AI Trajectory

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Seq	Timestamp	Type	Name	Duration
0/0	2026/09/12 02:35	flow	patch-triage	3m Args: null Results: { "EnableConfigs": [ "IP_VS", "IP_VS_PROTO_TCP", "IP_VS_FTP", "NF_CONNTRACK", "NF_NAT", "NF_CONNTRACK_FTP" ], "FocusSymbols": [ "ip_vs_schedule", "ip_vs_leave", "ip_vs_new_conn_out", "tcp_state_transition", "ip_vs_ftp_in", "ip_vs_ftp_out" ], "KMSANReasoning": "The patch introduces support for per-service hardened TCP state tracking (IP_VS_SVC_F_SECURE_TCP and IP_VS_CONN_F_SECURE_TCP) in IPVS. It allows connections belonging to a secure_tcp-enabled virtual service to use the existing hardened TCP state table (tcp_states_dos) rather than the default table, propagates this flag during connection creation and sync daemon handling (via IP_VS_CONN_F_BACKUP_MASK), and includes selftest utilities.\n\nAnalysis of uninitialized memory risk:\n1. Data structures \u0026 fields: The patch does not define new data structures or change the size, alignment, or padding of existing structures. It uses previously unused bit positions in existing integer fields (svc-\u003eflags and cp-\u003eflags).\n2. Initialization: Both struct ip_vs_service and struct ip_vs_conn have well-defined initialization routines (kzalloc and explicit member initialization in ip_vs_conn_new, respectively). Flags are initialized before use and propagated via standard bitwise operations on initialized variables.\n3. State lookup: The state table referenced (tcp_states_dos) is an existing, fully initialized static array of state transitions.\n4. User-space copies / info leaks: No uninitialized kernel memory or padding is exposed or copied to user space or across netlink/sockopt interfaces.\n\nAny potential defects in this patch (e.g., protocol state handling errors, synchronization or locking issues, or pointer dereferences) are functional bugs or within the scope of KASAN/LOCKDEP. There is no risk of uninitialized memory reads or information leaks detectable only by KMSAN. Therefore, a dedicated KMSAN session is not required.", "NeedsKMSAN": false, "Reasoning": "The patch adds support for per-service hardened TCP table configuration via new flags IP_VS_SVC_F_SECURE_TCP and IP_VS_CONN_F_SECURE_TCP. It updates connection creation logic in IPVS core and FTP helper routines to propagate the flag, and modifies the TCP state transition machine to select the DoS-hardened TCP state table when the connection flag is set. The code path is reachable in virtualized environments via standard IPVS netlink/setsockopt configuration and network traffic.", "WorthFuzzing": true }
1/1	2026/09/12 02:35	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit 99272cd2604c766adfa7ff72bd4a8cc0b203380b\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Sat Sep 12 02:35:44 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/include/uapi/linux/ip_vs.h b/include/uapi/linux/ip_vs.h\nindex 2c37c6ac7525a..34fcfaf13cd3f 100644\n--- a/include/uapi/linux/ip_vs.h\n+++ b/include/uapi/linux/ip_vs.h\n@@ -27,6 +27,7 @@\n \n #define IP_VS_SVC_F_SCHED_SH_FALLBACK\tIP_VS_SVC_F_SCHED1 /* SH fallback /\n #define IP_VS_SVC_F_SCHED_SH_PORT\tIP_VS_SVC_F_SCHED2 / SH use port /\n+#define IP_VS_SVC_F_SECURE_TCP\t0x0040\t\t/ use the hardened TCP table /\n \n /\n * IPVS sync daemon states\n@@ -89,6 +90,7 @@\n #define IP_VS_CONN_F_NO_CPORT\t0x0800\t\t/* no client port set yet /\n #define IP_VS_CONN_F_TEMPLATE\t0x1000\t\t/ template, not connection /\n #define IP_VS_CONN_F_ONE_PACKET\t0x2000\t\t/ forward only one packet /\n+#define IP_VS_CONN_F_SECURE_TCP\t0x0008\t\t/ use the hardened TCP table /\n \n / Initial bits allowed in backup server /\n #define IP_VS_CONN_F_BACKUP_MASK (IP_VS_CONN_F_FWD_MASK \| \\\n@@ -96,7 +98,8 @@\n \t\t\t\t IP_VS_CONN_F_INACTIVE \| \\\n \t\t\t\t IP_VS_CONN_F_SEQ_MASK \| \\\n \t\t\t\t IP_VS_CONN_F_NO_CPORT \| \\\n-\t\t\t\t IP_VS_CONN_F_TEMPLATE \\\n+\t\t\t\t IP_VS_CONN_F_TEMPLATE \| \\\n+\t\t\t\t IP_VS_CONN_F_SECURE_TCP \\\n \t\t\t\t )\n \n / Bits allowed to update in backup server /\ndiff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c\nindex ba0957798bad0..eead1b992dd96 100644\n--- a/net/netfilter/ipvs/ip_vs_core.c\n+++ b/net/netfilter/ipvs/ip_vs_core.c\n@@ -52,6 +52,13 @@\n #include \u003clinux/indirect_call_wrapper.h\u003e\n \n \n+/ Encode the per-service secure_tcp capability into a connection flag /\n+static inline unsigned int ip_vs_conn_secure_tcp_flags(struct ip_vs_service svc)\n+{\n+\treturn (svc-\u003eflags \u0026 IP_VS_SVC_F_SECURE_TCP) ?\n+\t\tIP_VS_CONN_F_SECURE_TCP : 0;\n+}\n+\n EXPORT_SYMBOL(register_ip_vs_scheduler);\n EXPORT_SYMBOL(unregister_ip_vs_scheduler);\n EXPORT_SYMBOL(ip_vs_proto_name);\n@@ -546,7 +553,9 @@ ip_vs_sched_persist(struct ip_vs_service svc,\n \t\t and thus param.pe_data will be destroyed\n \t\t * when the template expires /\n \t\tct = ip_vs_conn_new(\u0026param, dest-\u003eaf, \u0026dest-\u003eaddr, dport,\n-\t\t\t\t IP_VS_CONN_F_TEMPLATE, dest, skb-\u003emark);\n+\t\t\t\t IP_VS_CONN_F_TEMPLATE \|\n+\t\t\t\t ip_vs_conn_secure_tcp_flags(svc), dest,\n+\t\t\t\t skb-\u003emark);\n \t\tif (ct == NULL) {\n \t\t\tkfree(param.pe_data);\n \t\t\tignored = -1;\n@@ -567,6 +576,7 @@ ip_vs_sched_persist(struct ip_vs_service svc,\n \tflags = (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET\n \t\t \u0026\u0026 iph-\u003eprotocol == IPPROTO_UDP) ?\n \t\tIP_VS_CONN_F_ONE_PACKET : 0;\n+\tflags \|= ip_vs_conn_secure_tcp_flags(svc);\n \n \t/\n \t * Create a new connection according to the template\n@@ -714,6 +724,7 @@ ip_vs_schedule(struct ip_vs_service svc, struct sk_buff skb,\n \tflags = (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET\n \t\t \u0026\u0026 iph-\u003eprotocol == IPPROTO_UDP) ?\n \t\tIP_VS_CONN_F_ONE_PACKET : 0;\n+\tflags \|= ip_vs_conn_secure_tcp_flags(svc);\n \n \t/\n \t Create a connection entry.\n@@ -779,9 +790,10 @@ int ip_vs_leave(struct ip_vs_service svc, struct sk_buff skb,\n \t ip_vs_addr_is_unicast(net, svc-\u003eaf, \u0026iph-\u003edaddr)) {\n \t\tint ret;\n \t\tstruct ip_vs_conn cp;\n-\t\tunsigned int flags = (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET \u0026\u0026\n+\t\tunsigned int flags = ((svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET \u0026\u0026\n \t\t\t\t iph-\u003eprotocol == IPPROTO_UDP) ?\n-\t\t\t\t IP_VS_CONN_F_ONE_PACKET : 0;\n+\t\t\t\t IP_VS_CONN_F_ONE_PACKET : 0) \|\n+\t\t\t\t ip_vs_conn_secure_tcp_flags(svc);\n \t\tunion nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } };\n \n \t\t/ create a new connection entry /\n@@ -1350,7 +1362,9 @@ struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc,\n \t\t/ check if template exists and points to the same dest /\n \t\tif (!ct \|\| !ip_vs_check_template(ct, dest)) {\n \t\t\tct = ip_vs_conn_new(\u0026param, dest-\u003eaf, daddr, dport,\n-\t\t\t\t\t IP_VS_CONN_F_TEMPLATE, dest, 0);\n+\t\t\t\t\t IP_VS_CONN_F_TEMPLATE \|\n+\t\t\t\t\t ip_vs_conn_secure_tcp_flags(svc),\n+\t\t\t\t\t dest, 0);\n \t\t\tif (!ct) {\n \t\t\t\tkfree(param.pe_data);\n \t\t\t\treturn NULL;\n@@ -1364,6 +1378,7 @@ struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc,\n \t/ connection flags /\n \tflags = ((svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET) \u0026\u0026\n \t\t iph-\u003eprotocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0;\n+\tflags \|= ip_vs_conn_secure_tcp_flags(svc);\n \t/ create connection /\n \tip_vs_conn_fill_param(svc-\u003eipvs, svc-\u003eaf, iph-\u003eprotocol,\n \t\t\t caddr, cport, vaddr, vport, \u0026param);\ndiff --git a/net/netfilter/ipvs/ip_vs_ftp.c b/net/netfilter/ipvs/ip_vs_ftp.c\nindex b315c608fda43..73d2e79043038 100644\n--- a/net/netfilter/ipvs/ip_vs_ftp.c\n+++ b/net/netfilter/ipvs/ip_vs_ftp.c\n@@ -330,7 +330,8 @@ static int ip_vs_ftp_out(struct ip_vs_app app, struct ip_vs_conn cp,\n \t\t\t\t 0, \u0026cp-\u003evaddr, port, \u0026p);\n \t\tn_cp = ip_vs_conn_new(\u0026p, cp-\u003eaf, \u0026from, port,\n \t\t\t\t IP_VS_CONN_F_NO_CPORT \|\n-\t\t\t\t IP_VS_CONN_F_NFCT,\n+\t\t\t\t IP_VS_CONN_F_NFCT \|\n+\t\t\t\t (cp-\u003eflags \u0026 IP_VS_CONN_F_SECURE_TCP),\n \t\t\t\t cp-\u003edest, skb-\u003emark);\n \t\tif (!n_cp)\n \t\t\treturn 0;\n@@ -535,8 +536,9 @@ static int ip_vs_ftp_in(struct ip_vs_app app, struct ip_vs_conn cp,\n \t\tif (!n_cp) {\n \t\t\tn_cp = ip_vs_conn_new(\u0026p, cp-\u003eaf, \u0026cp-\u003edaddr,\n \t\t\t\t\t htons(ntohs(cp-\u003edport)-1),\n-\t\t\t\t\t IP_VS_CONN_F_NFCT, cp-\u003edest,\n-\t\t\t\t\t skb-\u003emark);\n+\t\t\t\t\t IP_VS_CONN_F_NFCT \|\n+\t\t\t\t\t (cp-\u003eflags \u0026 IP_VS_CONN_F_SECURE_TCP),\n+\t\t\t\t\t cp-\u003edest, skb-\u003emark);\n \t\t\tif (!n_cp)\n \t\t\t\treturn 0;\n \ndiff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c\nindex fec0e8b47b716..3b9a2c8e9a527 100644\n--- a/net/netfilter/ipvs/ip_vs_proto_tcp.c\n+++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c\n@@ -451,11 +451,10 @@ static void tcp_timeout_change(struct ip_vs_proto_data pd, int flags)\n \tint on = (flags \u0026 1);\t\t/* secure_tcp /\n \n \t/\n-\t FIXME: change secure_tcp to independent sysctl var\n-\t or make it per-service or per-app because it is valid\n-\t for most if not for all of the applications. Something\n-\t like \"capabilities\" (flags) for each object.\n-\t/\n+\t This remains the netns-wide default / global floor (e.g. when\n+\t * memory pressure kicks in). Per-service hardening is now carried\n+\t * by IP_VS_CONN_F_SECURE_TCP on each connection (set_tcp_state).\n+\t /\n \tpd-\u003etcp_state_table = (on ? tcp_states_dos : tcp_states);\n }\n \n@@ -479,6 +478,7 @@ set_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp,\n \tint state_idx;\n \tint new_state = IP_VS_TCP_S_CLOSE;\n \tint state_off = tcp_state_off[direction];\n+\tconst struct tcp_states_t table;\n \n \t/\n \t Update state offset to INPUT_ONLY if necessary\n@@ -496,8 +496,10 @@ set_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp,\n \t\tgoto tcp_state_out;\n \t}\n \n-\tnew_state =\n-\t\tpd-\u003etcp_state_table[state_off+state_idx].next_state[cp-\u003estate];\n+\ttable = pd-\u003etcp_state_table;\n+\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_SECURE_TCP)\n+\t\ttable = tcp_states_dos;\n+\tnew_state = table[state_off + state_idx].next_state[cp-\u003estate];\n \n tcp_state_out:\n \tif (new_state != cp-\u003estate) {\ndiff --git a/tools/testing/selftests/net/netfilter/Makefile b/tools/testing/selftests/net/netfilter/Makefile\nindex f88dd4ef8d264..fad05afadd41b 100644\n--- a/tools/testing/selftests/net/netfilter/Makefile\n+++ b/tools/testing/selftests/net/netfilter/Makefile\n@@ -20,6 +20,7 @@ TEST_PROGS := \\\n \tconntrack_tcp_unreplied.sh \\\n \tconntrack_vrf.sh \\\n \tipvs.sh \\\n+\tipvs_secure_tcp.sh \\\n \tnf_conntrack_packetdrill.sh \\\n \tnf_nat_edemux.sh \\\n \tnft_audit.sh \\\n@@ -50,6 +51,8 @@ TEST_GEN_FILES = \\\n \tconnect_close \\\n \tconntrack_dump_flush \\\n \tconntrack_reverse_clash \\\n+\tgen_tcp_probe \\\n+\tipvs_secure_tcp_mln \\\n \tnf_queue \\\n \tsctp_collision \\\n \tudpclash \\\n@@ -60,6 +63,9 @@ include ../../lib.mk\n $(OUTPUT)/nf_queue: CFLAGS += $(MNL_CFLAGS)\n $(OUTPUT)/nf_queue: LDLIBS += $(MNL_LDLIBS)\n \n+$(OUTPUT)/ipvs_secure_tcp_mln: CFLAGS += $(MNL_CFLAGS)\n+$(OUTPUT)/ipvs_secure_tcp_mln: LDLIBS += $(MNL_LDLIBS)\n+\n $(OUTPUT)/conntrack_dump_flush: CFLAGS += $(MNL_CFLAGS)\n $(OUTPUT)/conntrack_dump_flush: LDLIBS += $(MNL_LDLIBS)\n $(OUTPUT)/udpclash: LDLIBS += -lpthread\ndiff --git a/tools/testing/selftests/net/netfilter/gen_tcp_probe.c b/tools/testing/selftests/net/netfilter/gen_tcp_probe.c\nnew file mode 100644\nindex 0000000000000..d62bfdce70c06\n--- /dev/null\n+++ b/tools/testing/selftests/net/netfilter/gen_tcp_probe.c\n@@ -0,0 +1,127 @@\n+// SPDX-License-Identifier: GPL-2.0\n+/\n+ Send a TCP SYN then a TCP ACK (no SYN-ACK, no data) to the VIP.\n+ * IPVS's TCP state machine only inspects SYN/FIN/ACK/RST bits, so this\n+ * exercises the INPUT-direction state transition:\n+ \n+ SYN: NONE -\u003e SYN_RECV\n+ * ACK: SYN_RECV -\u003e ESTABLISHED (tcp_states, normal)\n+ * SYN_RECV -\u003e SYN_RECV (tcp_states_dos, secure_tcp)\n+ \n+ Requires CAP_NET_RAW.\n+ /\n+\n+#include \u003cstdio.h\u003e\n+#include \u003cstdlib.h\u003e\n+#include \u003cstring.h\u003e\n+#include \u003cunistd.h\u003e\n+#include \u003cstdint.h\u003e\n+#include \u003carpa/inet.h\u003e\n+#include \u003csys/socket.h\u003e\n+#include \u003cnetinet/ip.h\u003e\n+#include \u003cnetinet/tcp.h\u003e\n+#include \u003clinux/if_ether.h\u003e\n+\n+static inline uint16_t csump(const void data, size_t len)\n+{\n+\tconst uint16_t p = data;\n+\tuint32_t sum = 0;\n+\n+\twhile (len \u003e 1) {\n+\t\tsum += p++;\n+\t\tlen -= 2;\n+\t}\n+\tif (len)\n+\t\tsum += (const uint8_t )p;\n+\twhile (sum \u003e\u003e 16)\n+\t\tsum = (sum \u0026 0xffff) + (sum \u003e\u003e 16);\n+\treturn ~sum;\n+}\n+\n+static void send_seg(int fd, const struct in_addr sip, uint16_t sport,\n+\t\t const struct in_addr dip, uint16_t dport,\n+\t\t uint32_t seq, int syn, int ack)\n+{\n+\tuint8_t pkt[sizeof(struct iphdr) + sizeof(struct tcphdr)] = { 0 };\n+\tstruct iphdr ip = (struct iphdr )pkt;\n+\tstruct tcphdr tcp = (struct tcphdr )(pkt + sizeof(struct iphdr));\n+\tstruct sockaddr_in dst;\n+\n+\tip-\u003eversion = 4;\n+\tip-\u003eihl = 5;\n+\tip-\u003etot_len = htons(sizeof(pkt));\n+\tip-\u003eid = htons((uint16_t)(seq \u0026 0xffff));\n+\tip-\u003ettl = 64;\n+\tip-\u003eprotocol = IPPROTO_TCP;\n+\tip-\u003esaddr = sip-\u003es_addr;\n+\tip-\u003edaddr = dip-\u003es_addr;\n+\n+\ttcp-\u003esource = sport;\n+\ttcp-\u003edest = dport;\n+\ttcp-\u003eseq = htonl(seq);\n+\ttcp-\u003eack_seq = htonl(seq + 1);\n+\ttcp-\u003edoff = 5;\n+\tif (syn)\n+\t\ttcp-\u003esyn = 1;\n+\tif (ack)\n+\t\ttcp-\u003eack = 1;\n+\ttcp-\u003ewindow = htons(1024);\n+\n+\tip-\u003echeck = csump(ip, sizeof(struct iphdr));\n+\t/* pseudo header for TCP checksum /\n+\t{\n+\t\tuint8_t ph[12];\n+\n+\t\tmemcpy(ph, \u0026ip-\u003esaddr, 4);\n+\t\tmemcpy(ph + 4, \u0026ip-\u003edaddr, 4);\n+\t\tph[8] = 0;\n+\t\tph[9] = IPPROTO_TCP;\n+\t\tph[10] = (sizeof(struct tcphdr) \u003e\u003e 8) \u0026 0xff;\n+\t\tph[11] = sizeof(struct tcphdr) \u0026 0xff;\n+\n+\t\tuint8_t tcpbuf[12 + sizeof(struct tcphdr)];\n+\n+\t\tmemcpy(tcpbuf, ph, 12);\n+\t\tmemcpy(tcpbuf + 12, tcp, sizeof(struct tcphdr));\n+\t\ttcp-\u003echeck = csump(tcpbuf, sizeof(tcpbuf));\n+\t}\n+\n+\tmemset(\u0026dst, 0, sizeof(dst));\n+\tdst.sin_family = AF_INET;\n+\tdst.sin_addr = dip;\n+\tdst.sin_port = dport;\n+\tsendto(fd, pkt, sizeof(pkt), 0, (struct sockaddr )\u0026dst,\n+\t sizeof(dst));\n+}\n+\n+int main(int argc, char argv[])\n+{\n+\tstruct in_addr sip, dip;\n+\tuint16_t sport, dport;\n+\tint fd, one = 1;\n+\tuint32_t seq = 0x12345678;\n+\n+\tif (argc != 5) {\n+\t\tfprintf(stderr, \"usage: %s \u003csrc_ip\u003e \u003csrc_port\u003e \u003cdst_ip\u003e \u003cdst_port\u003e\\n\",\n+\t\t\targv[0]);\n+\t\treturn 2;\n+\t}\n+\tinet_pton(AF_INET, argv[1], \u0026sip);\n+\tsport = htons((uint16_t)atoi(argv[2]));\n+\tinet_pton(AF_INET, argv[3], \u0026dip);\n+\tdport = htons((uint16_t)atoi(argv[4]));\n+\n+\tfd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);\n+\tif (fd \u003c 0) {\n+\t\tperror(\"raw socket\");\n+\t\treturn 1;\n+\t}\n+\tsetsockopt(fd, IPPROTO_IP, IP_HDRINCL, \u0026one, sizeof(one));\n+\n+\tsend_seg(fd, \u0026sip, sport, \u0026dip, dport, seq, 1, 0);\n+\tusleep(100000);\n+\tsend_seg(fd, \u0026sip, sport, \u0026dip, dport, seq + 1, 0, 1);\n+\n+\tclose(fd);\n+\treturn 0;\n+}\ndiff --git a/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh\nnew file mode 100755\nindex 0000000000000..b079c0fe6b798\n--- /dev/null\n+++ b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh\n@@ -0,0 +1,158 @@\n+#!/bin/bash\n+# SPDX-License-Identifier: GPL-2.0\n+#\n+# Runtime test for per-service secure_tcp (IP_VS_SVC_F_SECURE_TCP).\n+#\n+# Sets up the same 3-namespace topology as ipvs.sh\n+# but checks the TCP state machine, not data forwarding. Two\n+# identical TCP services are added on the same VIP on different ports,\n+# one is marked secure_tcp, the other is not. For each a bare SYN is\n+# followed by a bare ACK (no SYN-ACK / no data). IPVS classifies the\n+# connection from the flag bits:\n+# * normal service: SYN -\u003e SYN_RECV, ACK -\u003e ESTABLISHED\n+# * secure_tcp service: SYN -\u003e SYN_RECV, ACK -\u003e SYN_RECV\n+# This test checks that this is the case via `ipvsadm -Lnc`.\n+#\n+# Requires root, netns, ipvsadm, nft, and the built helpers\n+# ipvs_secure_tcp_mln and gen_tcp_probe.\n+\n+source lib.sh\n+\n+ret=0\n+readonly vip=\"207.175.44.110\"\n+readonly gip=\"10.0.0.1\"\n+readonly dip=\"172.16.0.1\"\n+readonly rip=\"172.16.0.2\"\n+readonly cip=\"10.0.0.2\"\n+readonly sip=\"10.0.0.3\"\n+readonly port_secure=8081\n+readonly port_plain=8080\n+\n+GREEN='\\033[0;92m'\n+RED='\\033[0;31m'\n+NC='\\033[0m'\n+\n+checktool \"ipvsadm -v\" \"run test without ipvsadm\"\n+checktool \"nft --version\" \"run test without nft\"\n+\n+setup() {\n+\tsetup_ns ns0 ns1 ns2\n+\n+\tip link add veth01 netns \"${ns0}\" type veth peer name veth10 netns \"${ns1}\"\n+\tip link add veth02 netns \"${ns0}\" type veth peer name veth20 netns \"${ns2}\"\n+\tip link add veth12 netns \"${ns1}\" type veth peer name veth21 netns \"${ns2}\"\n+\n+\tip netns exec \"${ns0}\" ip link set veth01 up\n+\tip netns exec \"${ns0}\" ip link set veth02 up\n+\tip netns exec \"${ns0}\" ip link add br0 type bridge\n+\tip netns exec \"${ns0}\" ip link set veth01 master br0\n+\tip netns exec \"${ns0}\" ip link set veth02 master br0\n+\tip netns exec \"${ns0}\" ip link set br0 up\n+\tip netns exec \"${ns0}\" ip addr add \"${cip}/24\" dev br0\n+\n+\tip netns exec \"${ns1}\" ip link set veth10 up\n+\tip netns exec \"${ns1}\" ip addr add \"${gip}/24\" dev veth10\n+\tip netns exec \"${ns1}\" ip link set veth12 up\n+\tip netns exec \"${ns1}\" ip addr add \"${dip}/24\" dev veth12\n+\tip netns exec \"${ns1}\" ip link set lo up\n+\tip netns exec \"${ns1}\" ip addr add \"${vip}/32\" dev lo:1\n+\tip netns exec \"${ns1}\" sysctl -qw net.ipv4.ip_forward=1\n+\n+\tip netns exec \"${ns2}\" ip link set veth20 up\n+\tip netns exec \"${ns2}\" ip addr add \"${sip}/24\" dev veth20\n+\tip netns exec \"${ns2}\" ip link set veth21 up\n+\tip netns exec \"${ns2}\" ip addr add \"${rip}/24\" dev veth21\n+\n+\tip netns exec \"${ns2}\" ip addr add \"${vip}/32\" dev lo:1\n+\n+\tip netns exec \"${ns0}\" ip route add \"${vip}/32\" via \"${gip}\" dev br0\n+\n+\t# load ipvs, then the rr scheduler (separate calls: modprobe treats\n+\t# the second name as a module parameter, not a second module)\n+\tip netns exec \"${ns1}\" modprobe ip_vs\n+\tip netns exec \"${ns1}\" modprobe ip_vs_rr\n+\n+\tsleep 1\n+}\n+\n+cleanup() {\n+\tcleanup_all_ns\n+}\n+\n+# State of the connection to the VIP:port, from `ipvsadm -Lnc`.\n+# Fields: pro expire state source virtual destination\n+conn_state() {\n+\tlocal vport=$1\n+\tip netns exec \"${ns1}\" ipvsadm -Lnc 2\u003e/dev/null \|\n+\t\tawk -v vt=\"${vip}:${vport}\" '$5==vt { print $3; exit }'\n+}\n+\n+assert_state() {\n+\tlocal port=$1 want=$2\n+\tlocal got\n+\tgot=\"$(conn_state \"$port\")\"\n+\techo \" vip ${vip}:${port}: state=${got:-?}\"\n+\tif [ \"${got:-}\" != \"$want\" ]; then\n+\t\techo -e \"${RED}FAIL${NC}: vip ${vip}:${port} expected state\" \\\n+\t\t\t\"${want}, got ${got:-none}\"\n+\t\tret=1\n+\tfi\n+}\n+\n+test_secure() {\n+\tlocal bin probe\n+\n+\t# Register the two services (secure_tcp on the secure port)\n+\tbin=\"$(pwd)/ipvs_secure_tcp_mln\"\n+\tprobe=\"$(pwd)/gen_tcp_probe\"\n+\tip netns exec \"${ns1}\" \"$bin\" add \"${vip}\" \"${port_secure}\" secure\n+\tip netns exec \"${ns1}\" \"$bin\" add \"${vip}\" \"${port_plain}\" plain\n+\n+\t# Add a real server to both services. Use NAT (-m): in DR the conn gets\n+\t# IP_VS_CONN_F_NOOUTPUT, which makes the client ACK an INPUT_ONLY event\n+\t# and even tcp_states_dos promotes to ESTABLISHED, hiding the difference.\n+\tip netns exec \"${ns1}\" ipvsadm -a -m -t \"${vip}:${port_secure}\" -r \"${rip}:${port_secure}\"\n+\tip netns exec \"${ns1}\" ipvsadm -a -m -t \"${vip}:${port_plain}\" -r \"${rip}:${port_plain}\"\n+\n+\t# verify the flag was actually set\n+\tlocal got\n+\tgot=\"$(ip netns exec \"${ns1}\" \"$bin\" get \"${vip}\" \"${port_secure}\")\"\n+\techo \" secured service reports: ${got}\"\n+\techo \"${got}\" \| grep -q \"secure_tcp=1\" \|\|\n+\t\t{ echo -e \"${RED}FAIL${NC}: flag not set\"; ret=1; }\n+\tgot=\"$(ip netns exec \"${ns1}\" \"$bin\" get \"${vip}\" \"${port_plain}\")\"\n+\techo \"${got}\" \| grep -q \"secure_tcp=0\" \|\|\n+\t\t{ echo -e \"${RED}FAIL${NC}: flag unexpectedly set\"; ret=1; }\n+\n+\t# Drop any SYN on the real server so it stays silent (no RST that\n+\t# would interfere with the state-machine observation).\n+\tip netns exec \"${ns2}\" nft add table inet filter\n+\tip netns exec \"${ns2}\" nft add chain inet filter probe \\\n+\t\t'{ type filter hook input priority 0; }'\n+\tip netns exec \"${ns2}\" nft add rule inet filter probe \\\n+\t\ttcp dport '{ '\"${port_secure}\"', '\"${port_plain}\"' }' drop\n+\n+\t# Push SYN then ACK to each service from the client\n+\tip netns exec \"${ns0}\" \"$probe\" \"${cip}\" 40000 \"${vip}\" \"${port_secure}\"\n+\tip netns exec \"${ns0}\" \"$probe\" \"${cip}\" 40001 \"${vip}\" \"${port_plain}\"\n+\tsleep 1\n+\n+\techo \"Testing per-service secure_tcp...\"\n+\techo \" --- connection table (ipvsadm -Lnc) ---\"\n+\tip netns exec \"${ns1}\" ipvsadm -Lnc 2\u003e/dev/null\n+\techo \" --- end connection table ---\"\n+\tassert_state \"${port_plain}\" ESTABLISHED\n+\tassert_state \"${port_secure}\" SYN_RECV\n+}\n+\n+trap cleanup EXIT\n+\n+setup\n+test_secure\n+\n+if [ \"$ret\" -ne 0 ]; then\n+\techo -e \"$(basename $0): ${RED}FAIL${NC}\"\n+\texit 1\n+fi\n+echo -e \"$(basename $0): ${GREEN}PASS${NC}\"\n+exit 0\ndiff --git a/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c\nnew file mode 100644\nindex 0000000000000..c15a3c28e6fec\n--- /dev/null\n+++ b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c\n@@ -0,0 +1,310 @@\n+// SPDX-License-Identifier: GPL-2.0\n+/\n+ libmnl helper to set/query the per-service secure_tcp flag\n+ * (IP_VS_SVC_F_SECURE_TCP), which ipvsadm does not expose.\n+ \n+ Usage:\n+ * ipvs_secure_tcp_mln add \u003cvip\u003e \u003cport\u003e \u003csecure\|plain\u003e\n+ * Create a TCP virtual service (scheduler \"rr\") with the flag either\n+ * set or not. Add real servers afterwards with:\n+ * ipvsadm -a -t \u003cvip\u003e:\u003cport\u003e -r \u003crs\u003e:\u003cport\u003e\n+ * ipvs_secure_tcp_mln get \u003cvip\u003e \u003cport\u003e\n+ * Print \"secure_tcp=\u003c0\|1\u003e\" for the service.\n+ /\n+\n+#include \u003cstdio.h\u003e\n+#include \u003cstdlib.h\u003e\n+#include \u003cstring.h\u003e\n+#include \u003cerrno.h\u003e\n+#include \u003carpa/inet.h\u003e\n+\n+#include \u003clinux/netlink.h\u003e\n+#include \u003clinux/genetlink.h\u003e\n+#include \u003clinux/ip_vs.h\u003e\n+\n+#include \u003clibmnl/libmnl.h\u003e\n+\n+/ Fallback in case the kernel's installed uapi header is older /\n+#ifndef IP_VS_SVC_F_SECURE_TCP\n+#define IP_VS_SVC_F_SECURE_TCP\t0x0040\n+#endif\n+\n+/ 16-byte address storage, matching union nf_inet_addr for AF_INET /\n+struct inet_addr16 {\n+\tuint8_t all[16];\n+};\n+\n+/ ---------------- family resolver ---------------- /\n+static int ctrl_attr_cb(const struct nlattr attr, void data)\n+{\n+\tconst struct nlattr tb = data;\n+\tint type = mnl_attr_get_type(attr);\n+\n+\tif (mnl_attr_type_valid(attr, CTRL_ATTR_MAX) \u003c 0)\n+\t\treturn MNL_CB_ERROR;\n+\tif (type == CTRL_ATTR_FAMILY_ID) {\n+\t\tif (mnl_attr_validate(attr, MNL_TYPE_U16) \u003c 0)\n+\t\t\treturn MNL_CB_ERROR;\n+\t\ttb[CTRL_ATTR_FAMILY_ID] = attr;\n+\t}\n+\treturn MNL_CB_OK;\n+}\n+\n+static int ctrl_data_cb(const struct nlmsghdr nlh, void data)\n+{\n+\tconst struct nlattr tb[CTRL_ATTR_MAX + 1] = { 0 };\n+\tuint16_t fam = data;\n+\n+\tif (nlh-\u003enlmsg_type != GENL_ID_CTRL)\n+\t\treturn MNL_CB_OK;\n+\tmnl_attr_parse(nlh, sizeof(struct genlmsghdr),\n+\t\t (mnl_attr_cb_t)ctrl_attr_cb, tb);\n+\tif (tb[CTRL_ATTR_FAMILY_ID]) {\n+\t\tfam = mnl_attr_get_u16(tb[CTRL_ATTR_FAMILY_ID]);\n+\t\treturn MNL_CB_STOP;\n+\t}\n+\treturn MNL_CB_OK;\n+}\n+\n+static int resolve_family(const char name, uint16_t fam)\n+{\n+\tstruct mnl_socket nl;\n+\tchar buf[MNL_SOCKET_BUFFER_SIZE];\n+\tstruct nlmsghdr nlh;\n+\tstruct genlmsghdr genl;\n+\tint ret;\n+\n+\tnl = mnl_socket_open(NETLINK_GENERIC);\n+\tif (!nl)\n+\t\treturn -errno;\n+\tmnl_socket_bind(nl, 0, 0);\n+\n+\tnlh = mnl_nlmsg_put_header(buf);\n+\tgenl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr));\n+\tgenl-\u003ecmd = CTRL_CMD_GETFAMILY;\n+\tgenl-\u003eversion = 1;\n+\tnlh-\u003enlmsg_type = GENL_ID_CTRL;\n+\tnlh-\u003enlmsg_flags = NLM_F_REQUEST;\n+\tmnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, name);\n+\n+\tif (mnl_socket_sendto(nl, nlh, nlh-\u003enlmsg_len) \u003c 0) {\n+\t\tmnl_socket_close(nl);\n+\t\treturn -errno;\n+\t}\n+\tdo {\n+\t\tret = mnl_socket_recvfrom(nl, buf, sizeof(buf));\n+\t\tif (ret \u003c 0) {\n+\t\t\tif (errno == EAGAIN)\n+\t\t\t\tcontinue;\n+\t\t\tmnl_socket_close(nl);\n+\t\t\treturn -errno;\n+\t\t}\n+\t\tret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl),\n+\t\t\t\t (mnl_cb_t)ctrl_data_cb, fam);\n+\t} while (ret \u003e 0 \u0026\u0026 fam == 0);\n+\n+\tmnl_socket_close(nl);\n+\treturn fam ? 0 : -ENOENT;\n+}\n+\n+/ ---------------- fill service identifying attrs ---------------- /\n+static int fill_service(struct nlmsghdr nlh, const char vip,\n+\t\t\tuint16_t port, int full, int secure)\n+{\n+\tstruct inet_addr16 vaddr = { 0 };\n+\tstruct nlattr nest;\n+\tstruct ip_vs_flags fl;\n+\tint af = AF_INET;\n+\n+\tif (inet_pton(af, vip, vaddr.all) != 1) {\n+\t\tfprintf(stderr, \"bad VIP %s\\n\", vip);\n+\t\treturn -EINVAL;\n+\t}\n+\n+\tnest = mnl_attr_nest_start(nlh, IPVS_CMD_ATTR_SERVICE);\n+\tmnl_attr_put_u16(nlh, IPVS_SVC_ATTR_AF, af);\n+\tmnl_attr_put_u16(nlh, IPVS_SVC_ATTR_PROTOCOL, IPPROTO_TCP);\n+\tmnl_attr_put(nlh, IPVS_SVC_ATTR_ADDR, sizeof(vaddr), \u0026vaddr);\n+\t/* port/be16: port is passed in network order from main() /\n+\tmnl_attr_put_u16(nlh, IPVS_SVC_ATTR_PORT, port);\n+\n+\tif (full) {\n+\t\tmnl_attr_put_strz(nlh, IPVS_SVC_ATTR_SCHED_NAME, \"rr\");\n+\t\tmemset(\u0026fl, 0, sizeof(fl));\n+\t\tfl.mask = IP_VS_SVC_F_SECURE_TCP;\n+\t\tif (secure)\n+\t\t\tfl.flags = IP_VS_SVC_F_SECURE_TCP;\n+\t\tmnl_attr_put(nlh, IPVS_SVC_ATTR_FLAGS, sizeof(fl), \u0026fl);\n+\t\tmnl_attr_put_u32(nlh, IPVS_SVC_ATTR_TIMEOUT, 0);\n+\t\tmnl_attr_put_u32(nlh, IPVS_SVC_ATTR_NETMASK, 0xffffffff);\n+\t}\n+\tmnl_attr_nest_end(nlh, nest);\n+\treturn 0;\n+}\n+\n+static int send_cmd(struct mnl_socket nl, struct nlmsghdr nlh)\n+{\n+\tif (mnl_socket_sendto(nl, nlh, nlh-\u003enlmsg_len) \u003c 0) {\n+\t\tperror(\"sendto\");\n+\t\treturn -1;\n+\t}\n+\treturn 0;\n+}\n+\n+/ ---------------- get secure flag ---------------- /\n+static int svc_attr_cb(const struct nlattr attr, void data)\n+{\n+\tconst struct nlattr tb = data;\n+\tint type = mnl_attr_get_type(attr);\n+\n+\tif (mnl_attr_type_valid(attr, IPVS_SVC_ATTR_MAX) \u003c 0)\n+\t\treturn MNL_CB_ERROR;\n+\ttb[type] = attr;\n+\treturn MNL_CB_OK;\n+}\n+\n+static int get_cb(const struct nlmsghdr nlh, void data)\n+{\n+\tconst struct nlattr tb[IPVS_SVC_ATTR_MAX + 1] = { 0 };\n+\tstruct ip_vs_flags fl;\n+\tint secure = data;\n+\tstruct nlattr nest;\n+\n+\tmnl_attr_for_each(nest, nlh, sizeof(struct genlmsghdr)) {\n+\t\tif (mnl_attr_get_type(nest) == IPVS_CMD_ATTR_SERVICE)\n+\t\t\tmnl_attr_parse_nested(nest, (mnl_attr_cb_t)svc_attr_cb, tb);\n+\t}\n+\tif (tb[IPVS_SVC_ATTR_FLAGS]) {\n+\t\tmemcpy(\u0026fl, mnl_attr_get_payload(tb[IPVS_SVC_ATTR_FLAGS]),\n+\t\t sizeof(fl));\n+\t\tsecure = !!(fl.flags \u0026 IP_VS_SVC_F_SECURE_TCP);\n+\t}\n+\treturn MNL_CB_STOP;\n+}\n+\n+static int do_get(uint16_t fam, const char vip, uint16_t port)\n+{\n+\tstruct mnl_socket nl;\n+\tchar buf[MNL_SOCKET_BUFFER_SIZE];\n+\tstruct nlmsghdr nlh;\n+\tstruct genlmsghdr genl;\n+\tint ret, secure = -1;\n+\n+\tnl = mnl_socket_open(NETLINK_GENERIC);\n+\tmnl_socket_bind(nl, 0, 0);\n+\tnlh = mnl_nlmsg_put_header(buf);\n+\tgenl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr));\n+\tgenl-\u003ecmd = IPVS_CMD_GET_SERVICE;\n+\tgenl-\u003eversion = IPVS_GENL_VERSION;\n+\tnlh-\u003enlmsg_type = fam;\n+\tnlh-\u003enlmsg_flags = NLM_F_REQUEST;\n+\tfill_service(nlh, vip, port, 0, 0);\n+\tsend_cmd(nl, nlh);\n+\n+\tret = mnl_socket_recvfrom(nl, buf, sizeof(buf));\n+\twhile (ret \u003e= 0) {\n+\t\tret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl),\n+\t\t\t\t (mnl_cb_t)get_cb, \u0026secure);\n+\t\tif (ret \u003c= MNL_CB_STOP \|\| secure \u003e= 0)\n+\t\t\tbreak;\n+\t\tret = mnl_socket_recvfrom(nl, buf, sizeof(buf));\n+\t}\n+\tmnl_socket_close(nl);\n+\tif (secure \u003c 0)\n+\t\treturn -ENOENT;\n+\tprintf(\"secure_tcp=%d\\n\", secure);\n+\treturn 0;\n+}\n+\n+/ ---------------- add service with flag ---------------- /\n+static int do_add(uint16_t fam, const char vip, uint16_t port, int secure)\n+{\n+\tstruct mnl_socket nl;\n+\tchar buf[MNL_SOCKET_BUFFER_SIZE];\n+\tstruct nlmsghdr nlh;\n+\tstruct genlmsghdr genl;\n+\tint ret;\n+\n+\t/ NLM_F_EXCL: fail if the service already exists /\n+\tnlh = mnl_nlmsg_put_header(buf);\n+\tgenl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr));\n+\tgenl-\u003ecmd = IPVS_CMD_NEW_SERVICE;\n+\tgenl-\u003eversion = IPVS_GENL_VERSION;\n+\tnlh-\u003enlmsg_type = fam;\n+\tnlh-\u003enlmsg_flags = NLM_F_REQUEST \| NLM_F_ACK \| NLM_F_CREATE \| NLM_F_EXCL;\n+\tfill_service(nlh, vip, port, 1, secure);\n+\n+\tnl = mnl_socket_open(NETLINK_GENERIC);\n+\tmnl_socket_bind(nl, 0, 0);\n+\tif (send_cmd(nl, nlh) \u003c 0) {\n+\t\tmnl_socket_close(nl);\n+\t\treturn 1;\n+\t}\n+\n+\t/ Read the reply so we can report why a command may have failed /\n+\tfor (;;) {\n+\t\tret = mnl_socket_recvfrom(nl, buf, sizeof(buf));\n+\t\tif (ret \u003c= 0)\n+\t\t\tbreak;\n+\t\tret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl),\n+\t\t\t\t NULL, NULL);\n+\t\tif (ret \u003c 0) {\n+\t\t\tint e = errno;\n+\n+\t\t\tfprintf(stderr, \"IPVS netlink error: ret=%d errno=%d (%s)\\n\",\n+\t\t\t\tret, e, strerror(e));\n+\t\t\tmnl_socket_close(nl);\n+\t\t\treturn 1;\n+\t\t}\n+\t\tif (ret \u003c= MNL_CB_STOP)\n+\t\t\tbreak;\n+\t}\n+\tmnl_socket_close(nl);\n+\treturn 0;\n+}\n+\n+int main(int argc, char argv[])\n+{\n+\tconst char cmd, vip;\n+\tuint16_t fam;\n+\tuint16_t port;\n+\tint ret, secure = 0;\n+\n+\tif (argc \u003c 4) {\n+\t\tfprintf(stderr,\n+\t\t\t\"usage: %s add \u003cvip\u003e \u003cport\u003e \u003csecure\|plain\u003e\\n\"\n+\t\t\t\" %s get \u003cvip\u003e \u003cport\u003e\\n\", argv[0], argv[0]);\n+\t\treturn 2;\n+\t}\n+\tcmd = argv[1];\n+\tvip = argv[2];\n+\tport = (uint16_t)atoi(argv[3]);\n+\tport = htons(port);\n+\n+\tret = resolve_family(IPVS_GENL_NAME, \u0026fam);\n+\tif (ret) {\n+\t\tfprintf(stderr, \"cannot resolve IPVS genl family: %s\\n\",\n+\t\t\tstrerror(-ret));\n+\t\treturn 1;\n+\t}\n+\n+\tif (strcmp(cmd, \"add\") == 0) {\n+\t\tif (argc \u003c 5) {\n+\t\t\tfprintf(stderr, \"usage: %s add ... \u003csecure\|plain\u003e\\n\",\n+\t\t\t\targv[0]);\n+\t\t\treturn 2;\n+\t\t}\n+\t\tif (strcmp(argv[4], \"secure\") == 0) {\n+\t\t\tsecure = 1;\n+\t\t} else if (strcmp(argv[4], \"plain\") != 0) {\n+\t\t\tfprintf(stderr, \"unknown mode %s\\n\", argv[4]);\n+\t\t\treturn 2;\n+\t\t}\n+\t\treturn do_add(fam, vip, port, secure);\n+\t} else if (strcmp(cmd, \"get\") == 0) {\n+\t\treturn do_get(fam, vip, port);\n+\t}\n+\n+\tfprintf(stderr, \"unknown command %s\\n\", cmd);\n+\treturn 2;\n+}\n" }
2/1	2026/09/12 02:35	agent	patch-evaluator	1m Model: core Args: null Results: { "EnableConfigs": [ "IP_VS", "IP_VS_PROTO_TCP", "IP_VS_FTP", "NF_CONNTRACK", "NF_NAT", "NF_CONNTRACK_FTP" ], "FocusSymbols": [ "ip_vs_schedule", "ip_vs_leave", "ip_vs_new_conn_out", "tcp_state_transition", "ip_vs_ftp_in", "ip_vs_ftp_out" ], "Reasoning": "The patch adds support for per-service hardened TCP table configuration via new flags IP_VS_SVC_F_SECURE_TCP and IP_VS_CONN_F_SECURE_TCP. It updates connection creation logic in IPVS core and FTP helper routines to propagate the flag, and modifies the TCP state transition machine to select the DoS-hardened TCP state table when the connection flag is set. The code path is reachable in virtualized environments via standard IPVS netlink/setsockopt configuration and network traffic.", "WorthFuzzing": true } Instruction: You are an expert Linux kernel maintainer and security engineer. Your job is to review a provided patch series and evaluate whether it warrants fuzzing with syzkaller. IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in your workspace. Do NOT rely on internal assumptions. You must actively use your code access tools to inspect the actual source code, callers, and surrounding context. ================================================================================ 1. CORE TRIAGE PHILOSOPHY ================================================================================ The goal of patch fuzzing is to discover crashes, regressions, exposed latent bugs, and newly triggered assertions introduced by the patch series. - REACHABILITY IS THE PRIMARY GATE: Fuzzing can only discover bugs in code that can actually execute in standard virtualized environments (GCE or QEMU, utilizing software-emulated devices like USB gadgets, netdev, tun/tap). If the modified code is structurally unreachable (see Section 2), it MUST NOT be fuzzed, regardless of whether it adds assertions or complex logic. - DO NOT BLINDLY TRUST "NO FUNCTIONAL CHANGE" (NFCI) OR "REFACTORING" CLAIMS: Patch authors routinely label changes as "cleanups", "refactorings", or state "No functional change intended". Do NOT take these claims at face value. Code refactorings that rearrange logic, introduce helper functions, or alter state management in core subsystems frequently introduce subtle semantic shifts or uncover latent kernel bugs. If reachable executable code is modified or refactored, it MUST be fuzzed. - NEW OR MODIFIED ASSERTIONS IN REACHABLE CODE MUST BE FUZZED: When a patch introduces or modifies runtime checks or assertions (e.g., WARN_ON, VM_WARN_ON, BUG_ON, lockdep_assert) in reachable code paths, it enforces new or stricter invariants. Even if the author believes the invariant always holds, fuzzing is essential to verify whether an unusual sequence of operations can violate it. ================================================================================ 2. WHEN TO RETURN WorthFuzzing=false (NEGATIVE CRITERIA) ================================================================================ Return WorthFuzzing=false ONLY IF all modified code falls strictly into one or more of these categories: - Non-kernel and non-executable changes: * Modifications to Documentation/, comments, or spelling fixes. * User-space directories, self-tests, samples, or scripts (e.g., tools/, samples/, scripts/, usr/) that do not affect the compiled kernel image (vmlinux) or kernel modules. * Purely decorative logging (e.g., message strings in pr_err, printk, dev_info) or tracepoints that do not alter control flow or data structures. * Build system or Kconfig changes that do not alter compiled C logic. - Structurally unreachable hardware: * Vendor-specific PCIe switches, SmartNICs, or GPU drivers (e.g., mlxsw, pds_core, qed, ionic, amdgpu) requiring physical ASIC/PCIe cards not emulated in standard QEMU. - Unreachable execution paths: * Driver teardown callbacks (.remove, .shutdown, pci_unregister_driver) executed only during physical PCI hot-unplug or manual sysfs driver unbinding. * Code paths exclusive to architectures other than the target architecture. ================================================================================ 3. WHEN TO RETURN WorthFuzzing=true (POSITIVE CRITERIA) ================================================================================ Return WorthFuzzing=true whenever the patch touches reachable executable code, including: - Core Subsystems: * Any logic modifications in memory management (mm/), synchronization/locking (kernel/locking/), BPF, scheduler, core networking, VFS, or syscall handling. - Refactorings and Code Cleanups: * Any restructuring of reachable data structures, helper abstractions, or algorithm flows. - Runtime Assertions and Defensive Checks: * Any introduction or alteration of assertions (WARN_ON, VM_WARN_ON, BUG_ON, etc.) in reachable paths. - Reachable Drivers and Protocols: Drivers accessible via virtual buses (virtio, USB gadget, loopback, netlink, binder, sockets, etc.). ================================================================================ 4. EXTRACTING FocusSymbols (PREVENTING DILUTION) ================================================================================ When WorthFuzzing=true, you must extract specific kernel functions into FocusSymbols to guide the fuzzer: - AVOID UBIQUITOUS LIFECYCLE HOT-PATHS: Do NOT list generic, ubiquitous functions called by almost every program in the corpus (including, but not limited to: general memory allocators and deallocators, page fault and trap handlers, or core synchronization primitives; this is not an exhaustive list). Listing ubiquitous functions causes the fuzzer to classify thousands of unrelated tests as "focused", which severely dilutes fuzzing effort away from the actual changes. - TARGET SPECIFIC FEATURE LOGIC AND ENTRYPOINTS: List functions that specifically implement the logic being added or altered, or direct API entrypoints for the subsystem feature under review. - HANDLING STATIC INLINE FUNCTIONS IN HEADERS (.h): Compiler-inlined static functions (such as static inlines in mm/.h or include/linux/.h) lack distinct symbol addresses in vmlinux and cannot be targeted directly by symbol coverage filters. If the changes are primarily in static inline helpers, identify non-static, feature-specific caller functions in .c files that exercise them (avoiding ubiquitous lifecycle wrappers). ================================================================================ 5. IDENTIFYING EnableConfigs ================================================================================ Identify any specific CONFIG_ options required to properly compile and reach the modified code: - Inspect Kconfig files and #ifdef guards; do not make assumptions. - Check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed. - Strip any 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4"). Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: Target architecture: amd64 For your convenience, here is the diff of the changes: commit 99272cd2604c766adfa7ff72bd4a8cc0b203380b Author: syz-cluster <triage@syzkaller.com> Date: Sat Sep 12 02:35:44 2026 +0000 syz-cluster: applied patch under review diff --git a/include/uapi/linux/ip_vs.h b/include/uapi/linux/ip_vs.h index 2c37c6ac7525a..34fcfaf13cd3f 100644 --- a/include/uapi/linux/ip_vs.h +++ b/include/uapi/linux/ip_vs.h @@ -27,6 +27,7 @@ #define IP_VS_SVC_F_SCHED_SH_FALLBACK IP_VS_SVC_F_SCHED1 /* SH fallback / #define IP_VS_SVC_F_SCHED_SH_PORT IP_VS_SVC_F_SCHED2 / SH use port / +#define IP_VS_SVC_F_SECURE_TCP 0x0040 / use the hardened TCP table / / * IPVS sync daemon states @@ -89,6 +90,7 @@ #define IP_VS_CONN_F_NO_CPORT 0x0800 /* no client port set yet / #define IP_VS_CONN_F_TEMPLATE 0x1000 / template, not connection / #define IP_VS_CONN_F_ONE_PACKET 0x2000 / forward only one packet / +#define IP_VS_CONN_F_SECURE_TCP 0x0008 / use the hardened TCP table / / Initial bits allowed in backup server / #define IP_VS_CONN_F_BACKUP_MASK (IP_VS_CONN_F_FWD_MASK \| \ @@ -96,7 +98,8 @@ IP_VS_CONN_F_INACTIVE \| \ IP_VS_CONN_F_SEQ_MASK \| \ IP_VS_CONN_F_NO_CPORT \| \ - IP_VS_CONN_F_TEMPLATE \ + IP_VS_CONN_F_TEMPLATE \| \ + IP_VS_CONN_F_SECURE_TCP \ ) / Bits allowed to update in backup server / diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index ba0957798bad0..eead1b992dd96 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -52,6 +52,13 @@ #include <linux/indirect_call_wrapper.h> +/ Encode the per-service secure_tcp capability into a connection flag / +static inline unsigned int ip_vs_conn_secure_tcp_flags(struct ip_vs_service svc) +{ + return (svc->flags & IP_VS_SVC_F_SECURE_TCP) ? + IP_VS_CONN_F_SECURE_TCP : 0; +} + EXPORT_SYMBOL(register_ip_vs_scheduler); EXPORT_SYMBOL(unregister_ip_vs_scheduler); EXPORT_SYMBOL(ip_vs_proto_name); @@ -546,7 +553,9 @@ ip_vs_sched_persist(struct ip_vs_service svc, and thus param.pe_data will be destroyed * when the template expires / ct = ip_vs_conn_new(&param, dest->af, &dest->addr, dport, - IP_VS_CONN_F_TEMPLATE, dest, skb->mark); + IP_VS_CONN_F_TEMPLATE \| + ip_vs_conn_secure_tcp_flags(svc), dest, + skb->mark); if (ct == NULL) { kfree(param.pe_data); ignored = -1; @@ -567,6 +576,7 @@ ip_vs_sched_persist(struct ip_vs_service svc, flags = (svc->flags & IP_VS_SVC_F_ONEPACKET && iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0; + flags \|= ip_vs_conn_secure_tcp_flags(svc); / * Create a new connection according to the template @@ -714,6 +724,7 @@ ip_vs_schedule(struct ip_vs_service svc, struct sk_buff skb, flags = (svc->flags & IP_VS_SVC_F_ONEPACKET && iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0; + flags \|= ip_vs_conn_secure_tcp_flags(svc); /* * Create a connection entry. @@ -779,9 +790,10 @@ int ip_vs_leave(struct ip_vs_service svc, struct sk_buff skb, ip_vs_addr_is_unicast(net, svc->af, &iph->daddr)) { int ret; struct ip_vs_conn cp; - unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET && + unsigned int flags = ((svc->flags & IP_VS_SVC_F_ONEPACKET && iph->protocol == IPPROTO_UDP) ? - IP_VS_CONN_F_ONE_PACKET : 0; + IP_VS_CONN_F_ONE_PACKET : 0) \| + ip_vs_conn_secure_tcp_flags(svc); union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } }; / create a new connection entry / @@ -1350,7 +1362,9 @@ struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc, / check if template exists and points to the same dest / if (!ct \|\| !ip_vs_check_template(ct, dest)) { ct = ip_vs_conn_new(&param, dest->af, daddr, dport, - IP_VS_CONN_F_TEMPLATE, dest, 0); + IP_VS_CONN_F_TEMPLATE \| + ip_vs_conn_secure_tcp_flags(svc), + dest, 0); if (!ct) { kfree(param.pe_data); return NULL; @@ -1364,6 +1378,7 @@ struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc, / connection flags / flags = ((svc->flags & IP_VS_SVC_F_ONEPACKET) && iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0; + flags \|= ip_vs_conn_secure_tcp_flags(svc); / create connection / ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol, caddr, cport, vaddr, vport, &param); diff --git a/net/netfilter/ipvs/ip_vs_ftp.c b/net/netfilter/ipvs/ip_vs_ftp.c index b315c608fda43..73d2e79043038 100644 --- a/net/netfilter/ipvs/ip_vs_ftp.c +++ b/net/netfilter/ipvs/ip_vs_ftp.c @@ -330,7 +330,8 @@ static int ip_vs_ftp_out(struct ip_vs_app app, struct ip_vs_conn cp, 0, &cp->vaddr, port, &p); n_cp = ip_vs_conn_new(&p, cp->af, &from, port, IP_VS_CONN_F_NO_CPORT \| - IP_VS_CONN_F_NFCT, + IP_VS_CONN_F_NFCT \| + (cp->flags & IP_VS_CONN_F_SECURE_TCP), cp->dest, skb->mark); if (!n_cp) return 0; @@ -535,8 +536,9 @@ static int ip_vs_ftp_in(struct ip_vs_app app, struct ip_vs_conn cp, if (!n_cp) { n_cp = ip_vs_conn_new(&p, cp->af, &cp->daddr, htons(ntohs(cp->dport)-1), - IP_VS_CONN_F_NFCT, cp->dest, - skb->mark); + IP_VS_CONN_F_NFCT \| + (cp->flags & IP_VS_CONN_F_SECURE_TCP), + cp->dest, skb->mark); if (!n_cp) return 0; diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c index fec0e8b47b716..3b9a2c8e9a527 100644 --- a/net/netfilter/ipvs/ip_vs_proto_tcp.c +++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c @@ -451,11 +451,10 @@ static void tcp_timeout_change(struct ip_vs_proto_data pd, int flags) int on = (flags & 1); /* secure_tcp / / - FIXME: change secure_tcp to independent sysctl var - or make it per-service or per-app because it is valid - for most if not for all of the applications. Something - like "capabilities" (flags) for each object. - / + This remains the netns-wide default / global floor (e.g. when + * memory pressure kicks in). Per-service hardening is now carried + * by IP_VS_CONN_F_SECURE_TCP on each connection (set_tcp_state). + / pd->tcp_state_table = (on ? tcp_states_dos : tcp_states); } @@ -479,6 +478,7 @@ set_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp, int state_idx; int new_state = IP_VS_TCP_S_CLOSE; int state_off = tcp_state_off[direction]; + const struct tcp_states_t table; /* * Update state offset to INPUT_ONLY if necessary @@ -496,8 +496,10 @@ set_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp, goto tcp_state_out; } - new_state = - pd->tcp_state_table[state_off+state_idx].next_state[cp->state]; + table = pd->tcp_state_table; + if (cp->flags & IP_VS_CONN_F_SECURE_TCP) + table = tcp_states_dos; + new_state = table[state_off + state_idx].next_state[cp->state]; tcp_state_out: if (new_state != cp->state) { diff --git a/tools/testing/selftests/net/netfilter/Makefile b/tools/testing/selftests/net/netfilter/Makefile index f88dd4ef8d264..fad05afadd41b 100644 --- a/tools/testing/selftests/net/netfilter/Makefile +++ b/tools/testing/selftests/net/netfilter/Makefile @@ -20,6 +20,7 @@ TEST_PROGS := \ conntrack_tcp_unreplied.sh \ conntrack_vrf.sh \ ipvs.sh \ + ipvs_secure_tcp.sh \ nf_conntrack_packetdrill.sh \ nf_nat_edemux.sh \ nft_audit.sh \ @@ -50,6 +51,8 @@ TEST_GEN_FILES = \ connect_close \ conntrack_dump_flush \ conntrack_reverse_clash \ + gen_tcp_probe \ + ipvs_secure_tcp_mln \ nf_queue \ sctp_collision \ udpclash \ @@ -60,6 +63,9 @@ include ../../lib.mk $(OUTPUT)/nf_queue: CFLAGS += $(MNL_CFLAGS) $(OUTPUT)/nf_queue: LDLIBS += $(MNL_LDLIBS) +$(OUTPUT)/ipvs_secure_tcp_mln: CFLAGS += $(MNL_CFLAGS) +$(OUTPUT)/ipvs_secure_tcp_mln: LDLIBS += $(MNL_LDLIBS) + $(OUTPUT)/conntrack_dump_flush: CFLAGS += $(MNL_CFLAGS) $(OUTPUT)/conntrack_dump_flush: LDLIBS += $(MNL_LDLIBS) $(OUTPUT)/udpclash: LDLIBS += -lpthread diff --git a/tools/testing/selftests/net/netfilter/gen_tcp_probe.c b/tools/testing/selftests/net/netfilter/gen_tcp_probe.c new file mode 100644 index 0000000000000..d62bfdce70c06 --- /dev/null +++ b/tools/testing/selftests/net/netfilter/gen_tcp_probe.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Send a TCP SYN then a TCP ACK (no SYN-ACK, no data) to the VIP. + * IPVS's TCP state machine only inspects SYN/FIN/ACK/RST bits, so this + * exercises the INPUT-direction state transition: + * + * SYN: NONE -> SYN_RECV + * ACK: SYN_RECV -> ESTABLISHED (tcp_states, normal) + * SYN_RECV -> SYN_RECV (tcp_states_dos, secure_tcp) + * + * Requires CAP_NET_RAW. + / + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <stdint.h> +#include <arpa/inet.h> +#include <sys/socket.h> +#include <netinet/ip.h> +#include <netinet/tcp.h> +#include <linux/if_ether.h> + +static inline uint16_t csump(const void data, size_t len) +{ + const uint16_t p = data; + uint32_t sum = 0; + + while (len > 1) { + sum += p++; + len -= 2; + } + if (len) + sum += (const uint8_t )p; + while (sum >> 16) + sum = (sum & 0xffff) + (sum >> 16); + return ~sum; +} + +static void send_seg(int fd, const struct in_addr sip, uint16_t sport, + const struct in_addr dip, uint16_t dport, + uint32_t seq, int syn, int ack) +{ + uint8_t pkt[sizeof(struct iphdr) + sizeof(struct tcphdr)] = { 0 }; + struct iphdr ip = (struct iphdr )pkt; + struct tcphdr tcp = (struct tcphdr )(pkt + sizeof(struct iphdr)); + struct sockaddr_in dst; + + ip->version = 4; + ip->ihl = 5; + ip->tot_len = htons(sizeof(pkt)); + ip->id = htons((uint16_t)(seq & 0xffff)); + ip->ttl = 64; + ip->protocol = IPPROTO_TCP; + ip->saddr = sip->s_addr; + ip->daddr = dip->s_addr; + + tcp->source = sport; + tcp->dest = dport; + tcp->seq = htonl(seq); + tcp->ack_seq = htonl(seq + 1); + tcp->doff = 5; + if (syn) + tcp->syn = 1; + if (ack) + tcp->ack = 1; + tcp->window = htons(1024); + + ip->check = csump(ip, sizeof(struct iphdr)); + /* pseudo header for TCP checksum / + { + uint8_t ph[12]; + + memcpy(ph, &ip->saddr, 4); + memcpy(ph + 4, &ip->daddr, 4); + ph[8] = 0; + ph[9] = IPPROTO_TCP; + ph[10] = (sizeof(struct tcphdr) >> 8) & 0xff; + ph[11] = sizeof(struct tcphdr) & 0xff; + + uint8_t tcpbuf[12 + sizeof(struct tcphdr)]; + + memcpy(tcpbuf, ph, 12); + memcpy(tcpbuf + 12, tcp, sizeof(struct tcphdr)); + tcp->check = csump(tcpbuf, sizeof(tcpbuf)); + } + + memset(&dst, 0, sizeof(dst)); + dst.sin_family = AF_INET; + dst.sin_addr = dip; + dst.sin_port = dport; + sendto(fd, pkt, sizeof(pkt), 0, (struct sockaddr )&dst, + sizeof(dst)); +} + +int main(int argc, char argv[]) +{ + struct in_addr sip, dip; + uint16_t sport, dport; + int fd, one = 1; + uint32_t seq = 0x12345678; + + if (argc != 5) { + fprintf(stderr, "usage: %s <src_ip> <src_port> <dst_ip> <dst_port>\n", + argv[0]); + return 2; + } + inet_pton(AF_INET, argv[1], &sip); + sport = htons((uint16_t)atoi(argv[2])); + inet_pton(AF_INET, argv[3], &dip); + dport = htons((uint16_t)atoi(argv[4])); + + fd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW); + if (fd < 0) { + perror("raw socket"); + return 1; + } + setsockopt(fd, IPPROTO_IP, IP_HDRINCL, &one, sizeof(one)); + + send_seg(fd, &sip, sport, &dip, dport, seq, 1, 0); + usleep(100000); + send_seg(fd, &sip, sport, &dip, dport, seq + 1, 0, 1); + + close(fd); + return 0; +} diff --git a/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh new file mode 100755 index 0000000000000..b079c0fe6b798 --- /dev/null +++ b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh @@ -0,0 +1,158 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Runtime test for per-service secure_tcp (IP_VS_SVC_F_SECURE_TCP). +# +# Sets up the same 3-namespace topology as ipvs.sh +# but checks the TCP state machine, not data forwarding. Two +# identical TCP services are added on the same VIP on different ports, +# one is marked secure_tcp, the other is not. For each a bare SYN is +# followed by a bare ACK (no SYN-ACK / no data). IPVS classifies the +# connection from the flag bits: +# * normal service: SYN -> SYN_RECV, ACK -> ESTABLISHED +# * secure_tcp service: SYN -> SYN_RECV, ACK -> SYN_RECV +# This test checks that this is the case via `ipvsadm -Lnc`. +# +# Requires root, netns, ipvsadm, nft, and the built helpers +# ipvs_secure_tcp_mln and gen_tcp_probe. + +source lib.sh + +ret=0 +readonly vip="207.175.44.110" +readonly gip="10.0.0.1" +readonly dip="172.16.0.1" +readonly rip="172.16.0.2" +readonly cip="10.0.0.2" +readonly sip="10.0.0.3" +readonly port_secure=8081 +readonly port_plain=8080 + +GREEN='\033[0;92m' +RED='\033[0;31m' +NC='\033[0m' + +checktool "ipvsadm -v" "run test without ipvsadm" +checktool "nft --version" "run test without nft" + +setup() { + setup_ns ns0 ns1 ns2 + + ip link add veth01 netns "${ns0}" type veth peer name veth10 netns "${ns1}" + ip link add veth02 netns "${ns0}" type veth peer name veth20 netns "${ns2}" + ip link add veth12 netns "${ns1}" type veth peer name veth21 netns "${ns2}" + + ip netns exec "${ns0}" ip link set veth01 up + ip netns exec "${ns0}" ip link set veth02 up + ip netns exec "${ns0}" ip link add br0 type bridge + ip netns exec "${ns0}" ip link set veth01 master br0 + ip netns exec "${ns0}" ip link set veth02 master br0 + ip netns exec "${ns0}" ip link set br0 up + ip netns exec "${ns0}" ip addr add "${cip}/24" dev br0 + + ip netns exec "${ns1}" ip link set veth10 up + ip netns exec "${ns1}" ip addr add "${gip}/24" dev veth10 + ip netns exec "${ns1}" ip link set veth12 up + ip netns exec "${ns1}" ip addr add "${dip}/24" dev veth12 + ip netns exec "${ns1}" ip link set lo up + ip netns exec "${ns1}" ip addr add "${vip}/32" dev lo:1 + ip netns exec "${ns1}" sysctl -qw net.ipv4.ip_forward=1 + + ip netns exec "${ns2}" ip link set veth20 up + ip netns exec "${ns2}" ip addr add "${sip}/24" dev veth20 + ip netns exec "${ns2}" ip link set veth21 up + ip netns exec "${ns2}" ip addr add "${rip}/24" dev veth21 + + ip netns exec "${ns2}" ip addr add "${vip}/32" dev lo:1 + + ip netns exec "${ns0}" ip route add "${vip}/32" via "${gip}" dev br0 + + # load ipvs, then the rr scheduler (separate calls: modprobe treats + # the second name as a module parameter, not a second module) + ip netns exec "${ns1}" modprobe ip_vs + ip netns exec "${ns1}" modprobe ip_vs_rr + + sleep 1 +} + +cleanup() { + cleanup_all_ns +} + +# State of the connection to the VIP:port, from `ipvsadm -Lnc`. +# Fields: pro expire state source virtual destination +conn_state() { + local vport=$1 + ip netns exec "${ns1}" ipvsadm -Lnc 2>/dev/null \| + awk -v vt="${vip}:${vport}" '$5==vt { print $3; exit }' +} + +assert_state() { + local port=$1 want=$2 + local got + got="$(conn_state "$port")" + echo " vip ${vip}:${port}: state=${got:-?}" + if [ "${got:-}" != "$want" ]; then + echo -e "${RED}FAIL${NC}: vip ${vip}:${port} expected state" \ + "${want}, got ${got:-none}" + ret=1 + fi +} + +test_secure() { + local bin probe + + # Register the two services (secure_tcp on the secure port) + bin="$(pwd)/ipvs_secure_tcp_mln" + probe="$(pwd)/gen_tcp_probe" + ip netns exec "${ns1}" "$bin" add "${vip}" "${port_secure}" secure + ip netns exec "${ns1}" "$bin" add "${vip}" "${port_plain}" plain + + # Add a real server to both services. Use NAT (-m): in DR the conn gets + # IP_VS_CONN_F_NOOUTPUT, which makes the client ACK an INPUT_ONLY event + # and even tcp_states_dos promotes to ESTABLISHED, hiding the difference. + ip netns exec "${ns1}" ipvsadm -a -m -t "${vip}:${port_secure}" -r "${rip}:${port_secure}" + ip netns exec "${ns1}" ipvsadm -a -m -t "${vip}:${port_plain}" -r "${rip}:${port_plain}" + + # verify the flag was actually set + local got + got="$(ip netns exec "${ns1}" "$bin" get "${vip}" "${port_secure}")" + echo " secured service reports: ${got}" + echo "${got}" \| grep -q "secure_tcp=1" \|\| + { echo -e "${RED}FAIL${NC}: flag not set"; ret=1; } + got="$(ip netns exec "${ns1}" "$bin" get "${vip}" "${port_plain}")" + echo "${got}" \| grep -q "secure_tcp=0" \|\| + { echo -e "${RED}FAIL${NC}: flag unexpectedly set"; ret=1; } + + # Drop any SYN on the real server so it stays silent (no RST that + # would interfere with the state-machine observation). + ip netns exec "${ns2}" nft add table inet filter + ip netns exec "${ns2}" nft add chain inet filter probe \ + '{ type filter hook input priority 0; }' + ip netns exec "${ns2}" nft add rule inet filter probe \ + tcp dport '{ '"${port_secure}"', '"${port_plain}"' }' drop + + # Push SYN then ACK to each service from the client + ip netns exec "${ns0}" "$probe" "${cip}" 40000 "${vip}" "${port_secure}" + ip netns exec "${ns0}" "$probe" "${cip}" 40001 "${vip}" "${port_plain}" + sleep 1 + + echo "Testing per-service secure_tcp..." + echo " --- connection table (ipvsadm -Lnc) ---" + ip netns exec "${ns1}" ipvsadm -Lnc 2>/dev/null + echo " --- end connection table ---" + assert_state "${port_plain}" ESTABLISHED + assert_state "${port_secure}" SYN_RECV +} + +trap cleanup EXIT + +setup +test_secure + +if [ "$ret" -ne 0 ]; then + echo -e "$(basename $0): ${RED}FAIL${NC}" + exit 1 +fi +echo -e "$(basename $0): ${GREEN}PASS${NC}" +exit 0 diff --git a/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c new file mode 100644 index 0000000000000..c15a3c28e6fec --- /dev/null +++ b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * libmnl helper to set/query the per-service secure_tcp flag + * (IP_VS_SVC_F_SECURE_TCP), which ipvsadm does not expose. + * + * Usage: + * ipvs_secure_tcp_mln add <vip> <port> <secure\|plain> + * Create a TCP virtual service (scheduler "rr") with the flag either + * set or not. Add real servers afterwards with: + * ipvsadm -a -t <vip>:<port> -r <rs>:<port> + * ipvs_secure_tcp_mln get <vip> <port> + * Print "secure_tcp=<0\|1>" for the service. + / + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <arpa/inet.h> + +#include <linux/netlink.h> +#include <linux/genetlink.h> +#include <linux/ip_vs.h> + +#include <libmnl/libmnl.h> + +/ Fallback in case the kernel's installed uapi header is older / +#ifndef IP_VS_SVC_F_SECURE_TCP +#define IP_VS_SVC_F_SECURE_TCP 0x0040 +#endif + +/ 16-byte address storage, matching union nf_inet_addr for AF_INET / +struct inet_addr16 { + uint8_t all[16]; +}; + +/ ---------------- family resolver ---------------- / +static int ctrl_attr_cb(const struct nlattr attr, void data) +{ + const struct nlattr tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, CTRL_ATTR_MAX) < 0) + return MNL_CB_ERROR; + if (type == CTRL_ATTR_FAMILY_ID) { + if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0) + return MNL_CB_ERROR; + tb[CTRL_ATTR_FAMILY_ID] = attr; + } + return MNL_CB_OK; +} + +static int ctrl_data_cb(const struct nlmsghdr nlh, void data) +{ + const struct nlattr tb[CTRL_ATTR_MAX + 1] = { 0 }; + uint16_t fam = data; + + if (nlh->nlmsg_type != GENL_ID_CTRL) + return MNL_CB_OK; + mnl_attr_parse(nlh, sizeof(struct genlmsghdr), + (mnl_attr_cb_t)ctrl_attr_cb, tb); + if (tb[CTRL_ATTR_FAMILY_ID]) { + fam = mnl_attr_get_u16(tb[CTRL_ATTR_FAMILY_ID]); + return MNL_CB_STOP; + } + return MNL_CB_OK; +} + +static int resolve_family(const char name, uint16_t fam) +{ + struct mnl_socket nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr nlh; + struct genlmsghdr genl; + int ret; + + nl = mnl_socket_open(NETLINK_GENERIC); + if (!nl) + return -errno; + mnl_socket_bind(nl, 0, 0); + + nlh = mnl_nlmsg_put_header(buf); + genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); + genl->cmd = CTRL_CMD_GETFAMILY; + genl->version = 1; + nlh->nlmsg_type = GENL_ID_CTRL; + nlh->nlmsg_flags = NLM_F_REQUEST; + mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, name); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + mnl_socket_close(nl); + return -errno; + } + do { + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + if (ret < 0) { + if (errno == EAGAIN) + continue; + mnl_socket_close(nl); + return -errno; + } + ret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl), + (mnl_cb_t)ctrl_data_cb, fam); + } while (ret > 0 && fam == 0); + + mnl_socket_close(nl); + return fam ? 0 : -ENOENT; +} + +/ ---------------- fill service identifying attrs ---------------- / +static int fill_service(struct nlmsghdr nlh, const char vip, + uint16_t port, int full, int secure) +{ + struct inet_addr16 vaddr = { 0 }; + struct nlattr nest; + struct ip_vs_flags fl; + int af = AF_INET; + + if (inet_pton(af, vip, vaddr.all) != 1) { + fprintf(stderr, "bad VIP %s\n", vip); + return -EINVAL; + } + + nest = mnl_attr_nest_start(nlh, IPVS_CMD_ATTR_SERVICE); + mnl_attr_put_u16(nlh, IPVS_SVC_ATTR_AF, af); + mnl_attr_put_u16(nlh, IPVS_SVC_ATTR_PROTOCOL, IPPROTO_TCP); + mnl_attr_put(nlh, IPVS_SVC_ATTR_ADDR, sizeof(vaddr), &vaddr); + /* port/be16: port is passed in network order from main() / + mnl_attr_put_u16(nlh, IPVS_SVC_ATTR_PORT, port); + + if (full) { + mnl_attr_put_strz(nlh, IPVS_SVC_ATTR_SCHED_NAME, "rr"); + memset(&fl, 0, sizeof(fl)); + fl.mask = IP_VS_SVC_F_SECURE_TCP; + if (secure) + fl.flags = IP_VS_SVC_F_SECURE_TCP; + mnl_attr_put(nlh, IPVS_SVC_ATTR_FLAGS, sizeof(fl), &fl); + mnl_attr_put_u32(nlh, IPVS_SVC_ATTR_TIMEOUT, 0); + mnl_attr_put_u32(nlh, IPVS_SVC_ATTR_NETMASK, 0xffffffff); + } + mnl_attr_nest_end(nlh, nest); + return 0; +} + +static int send_cmd(struct mnl_socket nl, struct nlmsghdr nlh) +{ + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("sendto"); + return -1; + } + return 0; +} + +/ ---------------- get secure flag ---------------- / +static int svc_attr_cb(const struct nlattr attr, void data) +{ + const struct nlattr tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, IPVS_SVC_ATTR_MAX) < 0) + return MNL_CB_ERROR; + tb[type] = attr; + return MNL_CB_OK; +} + +static int get_cb(const struct nlmsghdr nlh, void data) +{ + const struct nlattr tb[IPVS_SVC_ATTR_MAX + 1] = { 0 }; + struct ip_vs_flags fl; + int secure = data; + struct nlattr nest; + + mnl_attr_for_each(nest, nlh, sizeof(struct genlmsghdr)) { + if (mnl_attr_get_type(nest) == IPVS_CMD_ATTR_SERVICE) + mnl_attr_parse_nested(nest, (mnl_attr_cb_t)svc_attr_cb, tb); + } + if (tb[IPVS_SVC_ATTR_FLAGS]) { + memcpy(&fl, mnl_attr_get_payload(tb[IPVS_SVC_ATTR_FLAGS]), + sizeof(fl)); + secure = !!(fl.flags & IP_VS_SVC_F_SECURE_TCP); + } + return MNL_CB_STOP; +} + +static int do_get(uint16_t fam, const char vip, uint16_t port) +{ + struct mnl_socket nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr nlh; + struct genlmsghdr genl; + int ret, secure = -1; + + nl = mnl_socket_open(NETLINK_GENERIC); + mnl_socket_bind(nl, 0, 0); + nlh = mnl_nlmsg_put_header(buf); + genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); + genl->cmd = IPVS_CMD_GET_SERVICE; + genl->version = IPVS_GENL_VERSION; + nlh->nlmsg_type = fam; + nlh->nlmsg_flags = NLM_F_REQUEST; + fill_service(nlh, vip, port, 0, 0); + send_cmd(nl, nlh); + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret >= 0) { + ret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl), + (mnl_cb_t)get_cb, &secure); + if (ret <= MNL_CB_STOP \|\| secure >= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + mnl_socket_close(nl); + if (secure < 0) + return -ENOENT; + printf("secure_tcp=%d\n", secure); + return 0; +} + +/ ---------------- add service with flag ---------------- / +static int do_add(uint16_t fam, const char vip, uint16_t port, int secure) +{ + struct mnl_socket nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr nlh; + struct genlmsghdr genl; + int ret; + + / NLM_F_EXCL: fail if the service already exists / + nlh = mnl_nlmsg_put_header(buf); + genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); + genl->cmd = IPVS_CMD_NEW_SERVICE; + genl->version = IPVS_GENL_VERSION; + nlh->nlmsg_type = fam; + nlh->nlmsg_flags = NLM_F_REQUEST \| NLM_F_ACK \| NLM_F_CREATE \| NLM_F_EXCL; + fill_service(nlh, vip, port, 1, secure); + + nl = mnl_socket_open(NETLINK_GENERIC); + mnl_socket_bind(nl, 0, 0); + if (send_cmd(nl, nlh) < 0) { + mnl_socket_close(nl); + return 1; + } + + / Read the reply so we can report why a command may have failed / + for (;;) { + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + if (ret <= 0) + break; + ret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl), + NULL, NULL); + if (ret < 0) { + int e = errno; + + fprintf(stderr, "IPVS netlink error: ret=%d errno=%d (%s)\n", + ret, e, strerror(e)); + mnl_socket_close(nl); + return 1; + } + if (ret <= MNL_CB_STOP) + break; + } + mnl_socket_close(nl); + return 0; +} + +int main(int argc, char argv[]) +{ + const char cmd, vip; + uint16_t fam; + uint16_t port; + int ret, secure = 0; + + if (argc < 4) { + fprintf(stderr, + "usage: %s add <vip> <port> <secure\|plain>\n" + " %s get <vip> <port>\n", argv[0], argv[0]); + return 2; + } + cmd = argv[1]; + vip = argv[2]; + port = (uint16_t)atoi(argv[3]); + port = htons(port); + + ret = resolve_family(IPVS_GENL_NAME, &fam); + if (ret) { + fprintf(stderr, "cannot resolve IPVS genl family: %s\n", + strerror(-ret)); + return 1; + } + + if (strcmp(cmd, "add") == 0) { + if (argc < 5) { + fprintf(stderr, "usage: %s add ... <secure\|plain>\n", + argv[0]); + return 2; + } + if (strcmp(argv[4], "secure") == 0) { + secure = 1; + } else if (strcmp(argv[4], "plain") != 0) { + fprintf(stderr, "unknown mode %s\n", argv[4]); + return 2; + } + return do_add(fam, vip, port, secure); + } else if (strcmp(cmd, "get") == 0) { + return do_get(fam, vip, port); + } + + fprintf(stderr, "unknown command %s\n", cmd); + return 2; +}
3/2	2026/09/12 02:35	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 13942 output: 36 thoughts: 591 Thoughts: My Analysis of the IPVS Patch Okay, so this patch is focused on IPVS, touching several key areas: `include/uapi/linux/ip_vs.h`, `net/netfilter/ipvs/ip_vs_core.c`, `net/netfilter/ipvs/ip_vs_ftp.c`, `net/netfilter/ipvs/ip_vs_proto_tcp.c`, and the selftests. Seems like a non-trivial change. I need to understand what this "SECURE_TCP" flag is all about. Diving into the code, in `include/uapi/linux/ip_vs.h`, I see that it defines `IP_VS_SVC_F_SECURE_TCP` and `IP_VS_CONN_F_SECURE_TCP`, adding the latter to `IP_VS_CONN_F_BACKUP_MASK`. This immediately tells me that this is a feature flag related to TCP connections, presumably to enable some form of enhanced security. The core logic appears to be in `net/netfilter/ipvs/ip_vs_core.c`. `ip_vs_conn_secure_tcp_flags` is the key function here. It sets the `IP_VS_CONN_F_SECURE_TCP` flag based on the service flag. I see it's used in several core connection handling functions: `ip_vs_sched_persist()`, `ip_vs_schedule()`, `ip_vs_leave()`, and `ip_vs_new_conn_out()`. This suggests the flag is propagated and used to influence connection scheduling and persistence behavior. Moving on to `net/netfilter/ipvs/ip_vs_ftp.c`, I see that `ip_vs_ftp_out()` and `ip_vs_ftp_in()` now propagate the `IP_VS_CONN_F_SECURE_TCP` flag to new connections. This makes sense; FTP control connections likely need to be treated consistently with the data connections they establish. Finally, in `net/netfilter/ipvs/ip_vs_proto_tcp.c`, there's a modification in `set_tcp_state`. The code now uses a different TCP state table (`tcp_states_dos`) if the `IP_VS_CONN_F_SECURE_TCP` flag is set. This is the most interesting part so far. This implies that the patch modifies the TCP state machine, likely to protect against certain DoS attacks. The original intent of this patch is clearer now. However, I'm left wondering: how is the user actually supposed to configure `IP_VS_SVC_F_SECURE_TCP`? Is it through `ipvsadm` or a new interface? I need to check how IPVS service flags are set and validated to understand how this feature is exposed to the user. I'll use `grepper` to figure that out. Time to dig deeper!
4/2	2026/09/12 02:35	tool	grepper	0m Args: { "Expression": "IP_VS_SVC_F_", "PathPrefix": "net/netfilter/ipvs/" } Results: { "Output": "net/netfilter/ipvs/ip_vs_conn.c=1837=static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn cp)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1843-\tsvc = rcu_dereference(cp-\u003edest-\u003esvc);\nnet/netfilter/ipvs/ip_vs_conn.c:1844:\treturn svc \u0026\u0026 (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET);\nnet/netfilter/ipvs/ip_vs_conn.c-1845-}\n--\nnet/netfilter/ipvs/ip_vs_core.c=56=static inline unsigned int ip_vs_conn_secure_tcp_flags(struct ip_vs_service svc)\nnet/netfilter/ipvs/ip_vs_core.c-57-{\nnet/netfilter/ipvs/ip_vs_core.c:58:\treturn (svc-\u003eflags \u0026 IP_VS_SVC_F_SECURE_TCP) ?\nnet/netfilter/ipvs/ip_vs_core.c-59-\t\tIP_VS_CONN_F_SECURE_TCP : 0;\n--\nnet/netfilter/ipvs/ip_vs_core.c=437=ip_vs_sched_persist(struct ip_vs_service svc,\n--\nnet/netfilter/ipvs/ip_vs_core.c-575-\nnet/netfilter/ipvs/ip_vs_core.c:576:\tflags = (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET\nnet/netfilter/ipvs/ip_vs_core.c-577-\t\t \u0026\u0026 iph-\u003eprotocol == IPPROTO_UDP) ?\n--\nnet/netfilter/ipvs/ip_vs_core.c=628=ip_vs_schedule(struct ip_vs_service svc, struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_core.c-693-\t /\nnet/netfilter/ipvs/ip_vs_core.c:694:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_PERSISTENT)\nnet/netfilter/ipvs/ip_vs_core.c-695-\t\treturn ip_vs_sched_persist(svc, skb, cport, vport, ignored,\n--\nnet/netfilter/ipvs/ip_vs_core.c-723-\nnet/netfilter/ipvs/ip_vs_core.c:724:\tflags = (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET\nnet/netfilter/ipvs/ip_vs_core.c-725-\t\t \u0026\u0026 iph-\u003eprotocol == IPPROTO_UDP) ?\n--\nnet/netfilter/ipvs/ip_vs_core.c=773=int ip_vs_leave(struct ip_vs_service svc, struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_core.c-792-\t\tstruct ip_vs_conn cp;\nnet/netfilter/ipvs/ip_vs_core.c:793:\t\tunsigned int flags = ((svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET \u0026\u0026\nnet/netfilter/ipvs/ip_vs_core.c-794-\t\t\t\t iph-\u003eprotocol == IPPROTO_UDP) ?\n--\nnet/netfilter/ipvs/ip_vs_core.c=1321=struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc,\n--\nnet/netfilter/ipvs/ip_vs_core.c-1346-\t/ for persistent service first create connection template /\nnet/netfilter/ipvs/ip_vs_core.c:1347:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_PERSISTENT) {\nnet/netfilter/ipvs/ip_vs_core.c-1348-\t\t/ apply netmask the same way ingress-side does /\n--\nnet/netfilter/ipvs/ip_vs_core.c-1378-\t/ connection flags /\nnet/netfilter/ipvs/ip_vs_core.c:1379:\tflags = ((svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET) \u0026\u0026\nnet/netfilter/ipvs/ip_vs_core.c-1380-\t\t iph-\u003eprotocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0;\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=382=static int ip_vs_svc_hash(struct ip_vs_service svc)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-388-\nnet/netfilter/ipvs/ip_vs_ctl.c:389:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_HASHED) {\nnet/netfilter/ipvs/ip_vs_ctl.c-390-\t\tpr_err(\"%s(): request for already hashed, called from %pS\\n\",\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-423-\tWRITE_ONCE(svc-\u003ehash_key, ip_vs_rht_build_hash_key(t, hash));\nnet/netfilter/ipvs/ip_vs_ctl.c:424:\tsvc-\u003eflags \|= IP_VS_SVC_F_HASHED;\nnet/netfilter/ipvs/ip_vs_ctl.c-425-\thlist_bl_add_head_rcu(\u0026svc-\u003es_list, head);\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=438=static int ip_vs_svc_unhash(struct ip_vs_service svc)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-445-\nnet/netfilter/ipvs/ip_vs_ctl.c:446:\tif (!(svc-\u003eflags \u0026 IP_VS_SVC_F_HASHED)) {\nnet/netfilter/ipvs/ip_vs_ctl.c-447-\t\tpr_err(\"%s(): request for unhash flagged, called from %pS\\n\",\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-481-\nnet/netfilter/ipvs/ip_vs_ctl.c:482:\tsvc-\u003eflags \u0026= ~IP_VS_SVC_F_HASHED;\nnet/netfilter/ipvs/ip_vs_ctl.c-483-\tatomic_dec(\u0026svc-\u003erefcnt);\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=1758=ip_vs_add_service(struct netns_ipvs ipvs, struct ip_vs_service_user_kern u,\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-1867-\tsvc-\u003efwmark = u-\u003efwmark;\nnet/netfilter/ipvs/ip_vs_ctl.c:1868:\tsvc-\u003eflags = u-\u003eflags \u0026 ~IP_VS_SVC_F_HASHED;\nnet/netfilter/ipvs/ip_vs_ctl.c-1869-\tsvc-\u003etimeout = u-\u003etimeout HZ;\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=1967=ip_vs_edit_service(struct ip_vs_service svc, struct ip_vs_service_user_kern u)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-2034-\t /\nnet/netfilter/ipvs/ip_vs_ctl.c:2035:\tsvc-\u003eflags = u-\u003eflags \| IP_VS_SVC_F_HASHED;\nnet/netfilter/ipvs/ip_vs_ctl.c-2036-\tsvc-\u003etimeout = u-\u003etimeout HZ;\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=3024=static int ip_vs_info_seq_show(struct seq_file seq, void v)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3057-\t\t\t\t\t sched_name,\nnet/netfilter/ipvs/ip_vs_ctl.c:3058:\t\t\t\t\t (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET)?\"ops \":\"\");\nnet/netfilter/ipvs/ip_vs_ctl.c-3059-\t\t} else {\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3061-\t\t\t\t svc-\u003efwmark, sched_name,\nnet/netfilter/ipvs/ip_vs_ctl.c:3062:\t\t\t\t (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET)?\"ops \":\"\");\nnet/netfilter/ipvs/ip_vs_ctl.c-3063-\t\t}\nnet/netfilter/ipvs/ip_vs_ctl.c-3064-\nnet/netfilter/ipvs/ip_vs_ctl.c:3065:\t\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_PERSISTENT)\nnet/netfilter/ipvs/ip_vs_ctl.c-3066-\t\t\tseq_printf(seq, \"persistent %d %08X\\n\",\n--\nnet/netfilter/ipvs/ip_vs_mh.c-33-\nnet/netfilter/ipvs/ip_vs_mh.c:34:#define IP_VS_SVC_F_SCHED_MH_FALLBACK\tIP_VS_SVC_F_SCHED1 /* MH fallback /\nnet/netfilter/ipvs/ip_vs_mh.c:35:#define IP_VS_SVC_F_SCHED_MH_PORT\tIP_VS_SVC_F_SCHED2 / MH use port /\nnet/netfilter/ipvs/ip_vs_mh.c-36-\n--\nnet/netfilter/ipvs/ip_vs_mh.c=471=ip_vs_mh_schedule(struct ip_vs_service svc, const struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_mh.c-482-\nnet/netfilter/ipvs/ip_vs_mh.c:483:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_SCHED_MH_PORT)\nnet/netfilter/ipvs/ip_vs_mh.c-484-\t\tport = ip_vs_mh_get_port(skb, iph);\n--\nnet/netfilter/ipvs/ip_vs_mh.c-487-\nnet/netfilter/ipvs/ip_vs_mh.c:488:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_SCHED_MH_FALLBACK)\nnet/netfilter/ipvs/ip_vs_mh.c-489-\t\tdest = ip_vs_mh_get_fallback(svc, s, hash_addr, port);\n--\nnet/netfilter/ipvs/ip_vs_sh.c=308=ip_vs_sh_schedule(struct ip_vs_service svc, const struct sk_buff *skb,\n--\nnet/netfilter/ipvs/ip_vs_sh.c-319-\nnet/netfilter/ipvs/ip_vs_sh.c:320:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_SCHED_SH_PORT)\nnet/netfilter/ipvs/ip_vs_sh.c-321-\t\tport = ip_vs_sh_get_port(skb, iph);\n--\nnet/netfilter/ipvs/ip_vs_sh.c-324-\nnet/netfilter/ipvs/ip_vs_sh.c:325:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_SCHED_SH_FALLBACK)\nnet/netfilter/ipvs/ip_vs_sh.c-326-\t\tdest = ip_vs_sh_get_fallback(svc, s, hash_addr, port);\n" }
5/2	2026/09/12 02:35	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 18220 output: 33 thoughts: 320 Thoughts: My Assessment of the IPVS Patch Okay, so this patch is introducing some new flags for IPVS, specifically `IP_VS_SVC_F_SECURE_TCP` (0x0040) for services and `IP_VS_CONN_F_SECURE_TCP` (0x0008) for connections. The core idea is that if a service is marked with this "secure TCP" flag, any new connections (or FTP sub-connections) inherit the connection flag. The actual behavior change happens within `set_tcp_state`; if that connection flag is set, it swaps out the standard `tcp_state_table` for `tcp_states_dos`. My immediate thought is: is this reachable? IPVS is a solid netfilter load-balancing component – part of the Linux kernel's standard networking stack, so the surface area should be wide enough. Services get added through netlink commands like `IPVS_CMD_NEW_SERVICE` and `IPVS_CMD_SET_SERVICE`, or even `setsockopt`, and tools like `ipvsadm`. Syzkaller should have everything described, in `netfilter_ipvs.txt` or genl ipvs. Crucially, the packet flow should be through the standard kernel paths, `ip_vs_in`, `ip_vs_schedule`, and finally, `set_tcp_state`, making it pretty well virtualized. I can run this in QEMU, network namespaces, veth, or even loopback. Nothing special there. Before I go further, I should check the Kconfig options for IPVS to nail down the precise configuration requirements. I need to be sure the relevant features are enabled, and I know where to look.
6/2	2026/09/12 02:35	tool	grepper	0m Args: { "Expression": "IP_VS", "PathPrefix": "net/netfilter/ipvs/Kconfig" } Results: { "Output": "net/netfilter/ipvs/Kconfig-4-#\nnet/netfilter/ipvs/Kconfig:5:menuconfig IP_VS\nnet/netfilter/ipvs/Kconfig-6-\ttristate \"IP virtual server support\"\n--\nnet/netfilter/ipvs/Kconfig-26-\nnet/netfilter/ipvs/Kconfig:27:if IP_VS\nnet/netfilter/ipvs/Kconfig-28-\nnet/netfilter/ipvs/Kconfig:29:config\tIP_VS_IPV6\nnet/netfilter/ipvs/Kconfig-30-\tbool \"IPv6 support for IPVS\"\nnet/netfilter/ipvs/Kconfig:31:\tdepends on IPV6 = y \|\| IP_VS = IPV6\nnet/netfilter/ipvs/Kconfig-32-\tselect NF_DEFRAG_IPV6\n--\nnet/netfilter/ipvs/Kconfig-37-\nnet/netfilter/ipvs/Kconfig:38:config\tIP_VS_DEBUG\nnet/netfilter/ipvs/Kconfig-39-\tbool \"IP virtual server debugging\"\n--\nnet/netfilter/ipvs/Kconfig-44-\nnet/netfilter/ipvs/Kconfig:45:config\tIP_VS_TAB_BITS\nnet/netfilter/ipvs/Kconfig-46-\tint \"IPVS connection table size (the Nth power of 2)\"\n--\nnet/netfilter/ipvs/Kconfig=77=comment \"IPVS transport protocol load balancing support\"\nnet/netfilter/ipvs/Kconfig-78-\nnet/netfilter/ipvs/Kconfig:79:config\tIP_VS_PROTO_TCP\nnet/netfilter/ipvs/Kconfig-80-\tbool \"TCP load balancing support\"\n--\nnet/netfilter/ipvs/Kconfig-84-\nnet/netfilter/ipvs/Kconfig:85:config\tIP_VS_PROTO_UDP\nnet/netfilter/ipvs/Kconfig-86-\tbool \"UDP load balancing support\"\n--\nnet/netfilter/ipvs/Kconfig-90-\nnet/netfilter/ipvs/Kconfig:91:config\tIP_VS_PROTO_AH_ESP\nnet/netfilter/ipvs/Kconfig:92:\tdef_bool IP_VS_PROTO_ESP \|\| IP_VS_PROTO_AH\nnet/netfilter/ipvs/Kconfig-93-\nnet/netfilter/ipvs/Kconfig:94:config\tIP_VS_PROTO_ESP\nnet/netfilter/ipvs/Kconfig-95-\tbool \"ESP load balancing support\"\n--\nnet/netfilter/ipvs/Kconfig-99-\nnet/netfilter/ipvs/Kconfig:100:config\tIP_VS_PROTO_AH\nnet/netfilter/ipvs/Kconfig-101-\tbool \"AH load balancing support\"\n--\nnet/netfilter/ipvs/Kconfig-105-\nnet/netfilter/ipvs/Kconfig:106:config IP_VS_PROTO_SCTP\nnet/netfilter/ipvs/Kconfig-107-\tbool \"SCTP load balancing support\"\n--\nnet/netfilter/ipvs/Kconfig=113=comment \"IPVS scheduler\"\nnet/netfilter/ipvs/Kconfig-114-\nnet/netfilter/ipvs/Kconfig:115:config\tIP_VS_RR\nnet/netfilter/ipvs/Kconfig-116-\ttristate \"round-robin scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-123- \nnet/netfilter/ipvs/Kconfig:124:config\tIP_VS_WRR\nnet/netfilter/ipvs/Kconfig-125-\ttristate \"weighted round-robin scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-136-\nnet/netfilter/ipvs/Kconfig:137:config\tIP_VS_LC\nnet/netfilter/ipvs/Kconfig-138-\ttristate \"least-connection scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-146-\nnet/netfilter/ipvs/Kconfig:147:config\tIP_VS_WLC\nnet/netfilter/ipvs/Kconfig-148-\ttristate \"weighted least-connection scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-156-\nnet/netfilter/ipvs/Kconfig:157:config IP_VS_FO\nnet/netfilter/ipvs/Kconfig-158-\t\ttristate \"weighted failover scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-166-\nnet/netfilter/ipvs/Kconfig:167:config IP_VS_OVF\nnet/netfilter/ipvs/Kconfig-168-\ttristate \"weighted overflow scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-177-\nnet/netfilter/ipvs/Kconfig:178:config\tIP_VS_LBLC\nnet/netfilter/ipvs/Kconfig-179-\ttristate \"locality-based least-connection scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-191-\nnet/netfilter/ipvs/Kconfig:192:config IP_VS_LBLCR\nnet/netfilter/ipvs/Kconfig-193-\ttristate \"locality-based least-connection with replication scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-209-\nnet/netfilter/ipvs/Kconfig:210:config\tIP_VS_DH\nnet/netfilter/ipvs/Kconfig-211-\ttristate \"destination hashing scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-219-\nnet/netfilter/ipvs/Kconfig:220:config\tIP_VS_SH\nnet/netfilter/ipvs/Kconfig-221-\ttristate \"source hashing scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-229-\nnet/netfilter/ipvs/Kconfig:230:config\tIP_VS_MH\nnet/netfilter/ipvs/Kconfig-231-\ttristate \"maglev hashing scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-248-\nnet/netfilter/ipvs/Kconfig:249:config\tIP_VS_SED\nnet/netfilter/ipvs/Kconfig-250-\ttristate \"shortest expected delay scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-261-\nnet/netfilter/ipvs/Kconfig:262:config\tIP_VS_NQ\nnet/netfilter/ipvs/Kconfig-263-\ttristate \"never queue scheduling\"\n--\nnet/netfilter/ipvs/Kconfig-274-\nnet/netfilter/ipvs/Kconfig:275:config\tIP_VS_TWOS\nnet/netfilter/ipvs/Kconfig-276-\ttristate \"weighted random twos choice least-connection scheduling\"\n--\nnet/netfilter/ipvs/Kconfig=286=comment 'IPVS SH scheduler'\nnet/netfilter/ipvs/Kconfig-287-\nnet/netfilter/ipvs/Kconfig:288:config IP_VS_SH_TAB_BITS\nnet/netfilter/ipvs/Kconfig-289-\tint \"IPVS source hashing table size (the Nth power of 2)\"\n--\nnet/netfilter/ipvs/Kconfig=301=comment 'IPVS MH scheduler'\nnet/netfilter/ipvs/Kconfig-302-\nnet/netfilter/ipvs/Kconfig:303:config IP_VS_MH_TAB_INDEX\nnet/netfilter/ipvs/Kconfig-304-\tint \"IPVS maglev hashing table index of size (the prime numbers)\"\n--\nnet/netfilter/ipvs/Kconfig=319=comment 'IPVS application helper'\nnet/netfilter/ipvs/Kconfig-320-\nnet/netfilter/ipvs/Kconfig:321:config\tIP_VS_FTP\nnet/netfilter/ipvs/Kconfig-322-\ttristate \"FTP protocol helper\"\nnet/netfilter/ipvs/Kconfig:323:\tdepends on IP_VS_PROTO_TCP \u0026\u0026 NF_CONNTRACK \u0026\u0026 NF_NAT \u0026\u0026 \\\nnet/netfilter/ipvs/Kconfig-324-\t\tNF_CONNTRACK_FTP\nnet/netfilter/ipvs/Kconfig:325:\tselect IP_VS_NFCT\nnet/netfilter/ipvs/Kconfig-326-\thelp\n--\nnet/netfilter/ipvs/Kconfig-336-\nnet/netfilter/ipvs/Kconfig:337:config\tIP_VS_NFCT\nnet/netfilter/ipvs/Kconfig-338-\tbool \"Netfilter connection tracking\"\n--\nnet/netfilter/ipvs/Kconfig-344-\nnet/netfilter/ipvs/Kconfig:345:config\tIP_VS_PE_SIP\nnet/netfilter/ipvs/Kconfig-346-\ttristate \"SIP persistence engine\"\nnet/netfilter/ipvs/Kconfig:347:\tdepends on IP_VS_PROTO_UDP\nnet/netfilter/ipvs/Kconfig-348-\tdepends on NF_CONNTRACK_SIP\n--\nnet/netfilter/ipvs/Kconfig=352=config GCOV_PROFILE_IPVS\n--\nnet/netfilter/ipvs/Kconfig-360-\nnet/netfilter/ipvs/Kconfig:361:endif # IP_VS\n" }
7/2	2026/09/12 02:35	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 21354 output: 36 thoughts: 71 Thoughts: Here's my thinking process: Diving into the Build Configuration Okay, so I've been working on these IPVS modules: `ip_vs_core.c`, `ip_vs_ftp.c`, and `ip_vs_proto_tcp.c`. Now, the next logical step is to understand precisely how these changes will impact the build process. I need to figure out which configurations are actually going to use these updated files. The best place to start is, naturally, the `Makefile`. That's where all the build magic happens. I'll need to carefully examine it to determine the dependencies and the specific build targets affected by these particular source files. This will tell me what configurations I need to test thoroughly to ensure my changes haven't introduced any regressions or unexpected behavior. Right, let's get to it.
8/2	2026/09/12 02:36	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/Kconfig", "FirstLine": 1, "LineCount": 40 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0-only\n 2:\t#\n 3:\t# IP Virtual Server configuration\n 4:\t#\n 5:\tmenuconfig IP_VS\n 6:\t\ttristate \"IP virtual server support\"\n 7:\t\tdepends on INET \u0026\u0026 NETFILTER\n 8:\t\tdepends on (NF_CONNTRACK \|\| NF_CONNTRACK=n)\n 9:\t\thelp\n 10:\t\t IP Virtual Server support will let you build a high-performance\n 11:\t\t virtual server based on cluster of two or more real servers. This\n 12:\t\t option must be enabled for at least one of the clustered computers\n 13:\t\t that will take care of intercepting incoming connections to a\n 14:\t\t single IP address and scheduling them to real servers.\n 15:\t\n 16:\t\t Three request dispatching techniques are implemented, they are\n 17:\t\t virtual server via NAT, virtual server via tunneling and virtual\n 18:\t\t server via direct routing. The several scheduling algorithms can\n 19:\t\t be used to choose which server the connection is directed to,\n 20:\t\t thus load balancing can be achieved among the servers. For more\n 21:\t\t information and its administration program, please visit the\n 22:\t\t following URL: \u003chttp://www.linuxvirtualserver.org/\u003e.\n 23:\t\n 24:\t\t If you want to compile it in kernel, say Y. To compile it as a\n 25:\t\t module, choose M here. If unsure, say N.\n 26:\t\n 27:\tif IP_VS\n 28:\t\n 29:\tconfig\tIP_VS_IPV6\n 30:\t\tbool \"IPv6 support for IPVS\"\n 31:\t\tdepends on IPV6 = y \|\| IP_VS = IPV6\n 32:\t\tselect NF_DEFRAG_IPV6\n 33:\t\thelp\n 34:\t\t Add IPv6 support to IPVS.\n 35:\t\n 36:\t\t Say Y if unsure.\n 37:\t\n 38:\tconfig\tIP_VS_DEBUG\n 39:\t\tbool \"IP virtual server debugging\"\n 40:\t\thelp\n" }
9/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 22200 output: 35 thoughts: 15 Thoughts: Here's a summary of my thought process, as if I were considering that Makefile: Analyzing the IPVS Makefile Okay, time to dive into `net/netfilter/ipvs/Makefile`. Given my experience with IPVS and the kernel build process, I'm likely looking for a few key things here. First, I'll be scanning for the overall build structure. What are the dependencies? How are the source files organized? Are there any obvious conditional compilations based on kernel versions or configuration options? I need to understand the relationship between the various `.c` files and how they're compiled into the IPVS module. I'll be paying close attention to any `obj-m` assignments, as those will define the modules being built. I also need to verify that all the necessary headers are included and properly handled. Next, I'll examine the rules themselves. Are the compilation flags standard or are there any unusual optimizations or debug flags being used? Does the Makefile employ any specific kernel build macros or helpers? I want to see if the build process is clean, well-documented (ideally, though that's often a stretch!), and follows established kernel coding conventions. Are there any potential build-time issues that might arise on different architectures or with specific kernel configurations? I'm looking for anything that could break or cause unexpected behavior when I configure or rebuild the module. Finally, I'll check for any post-processing steps or installation targets related to this module.
10/2	2026/09/12 02:36	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/Makefile", "FirstLine": 1, "LineCount": 50 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0\n 2:\t#\n 3:\t# Makefile for the IPVS modules on top of IPv4.\n 4:\t#\n 5:\t\n 6:\t# IPVS transport protocol load balancing support\n 7:\tip_vs_proto-objs-y :=\n 8:\tip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_TCP) += ip_vs_proto_tcp.o\n 9:\tip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_UDP) += ip_vs_proto_udp.o\n 10:\tip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_AH_ESP) += ip_vs_proto_ah_esp.o\n 11:\tip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_SCTP) += ip_vs_proto_sctp.o\n 12:\t\n 13:\tip_vs-extra_objs-y :=\n 14:\tip_vs-extra_objs-$(CONFIG_IP_VS_NFCT) += ip_vs_nfct.o\n 15:\t\n 16:\tip_vs-objs :=\tip_vs_conn.o ip_vs_core.o ip_vs_ctl.o ip_vs_sched.o\t \\\n 17:\t\t\tip_vs_xmit.o ip_vs_app.o ip_vs_sync.o\t \t\t \\\n 18:\t\t\tip_vs_est.o ip_vs_proto.o ip_vs_pe.o\t\t\t \\\n 19:\t\t\t$(ip_vs_proto-objs-y) $(ip_vs-extra_objs-y)\n 20:\t\n 21:\t\n 22:\t# IPVS core\n 23:\tobj-$(CONFIG_IP_VS) += ip_vs.o\n 24:\t\n 25:\t# IPVS schedulers\n 26:\tobj-$(CONFIG_IP_VS_RR) += ip_vs_rr.o\n 27:\tobj-$(CONFIG_IP_VS_WRR) += ip_vs_wrr.o\n 28:\tobj-$(CONFIG_IP_VS_LC) += ip_vs_lc.o\n 29:\tobj-$(CONFIG_IP_VS_WLC) += ip_vs_wlc.o\n 30:\tobj-$(CONFIG_IP_VS_FO) += ip_vs_fo.o\n 31:\tobj-$(CONFIG_IP_VS_OVF) += ip_vs_ovf.o\n 32:\tobj-$(CONFIG_IP_VS_LBLC) += ip_vs_lblc.o\n 33:\tobj-$(CONFIG_IP_VS_LBLCR) += ip_vs_lblcr.o\n 34:\tobj-$(CONFIG_IP_VS_DH) += ip_vs_dh.o\n 35:\tobj-$(CONFIG_IP_VS_SH) += ip_vs_sh.o\n 36:\tobj-$(CONFIG_IP_VS_MH) += ip_vs_mh.o\n 37:\tobj-$(CONFIG_IP_VS_SED) += ip_vs_sed.o\n 38:\tobj-$(CONFIG_IP_VS_NQ) += ip_vs_nq.o\n 39:\tobj-$(CONFIG_IP_VS_TWOS) += ip_vs_twos.o\n 40:\t\n 41:\t# IPVS application helpers\n 42:\tobj-$(CONFIG_IP_VS_FTP) += ip_vs_ftp.o\n 43:\t\n 44:\t# IPVS connection template retrievers\n 45:\tobj-$(CONFIG_IP_VS_PE_SIP) += ip_vs_pe_sip.o\n 46:\tifdef CONFIG_GCOV_PROFILE_IPVS\n 47:\tGCOV_PROFILE := y\n 48:\tendif\n" }
11/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 23545 output: 37 thoughts: 101 Thoughts: Kernel Configuration Conundrums Okay, so I'm diving into this kernel configuration, and it looks like `CONFIG_IP_VS` is the big kahuna, the main switch for IP Virtual Server functionality. That much is clear. Now, if I need the TCP protocol support – and let's face it, that's often the case – I'm going to need `CONFIG_IP_VS_PROTO_TCP`, which links to `ip_vs_proto_tcp.o`. While it should be set to "y" automatically if I enable `CONFIG_IP_VS`, it's always best to be sure, so I should double-check the Kconfig file on line 79. Just to be thorough. And, if I'm looking at FTP support? That will mean needing the `CONFIG_IP_VS_FTP`, which relates to the `ip_vs_ftp.o` module. I should also have a look at the Kconfig file to confirm whether `CONFIG_IP_VS_PROTO_TCP` is indeed being set up correctly.
12/2	2026/09/12 02:36	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/Kconfig", "FirstLine": 75, "LineCount": 20 } Results: { "Contents": " 75:\t\t IP VS was compiled built-in.\n 76:\t\n 77:\tcomment \"IPVS transport protocol load balancing support\"\n 78:\t\n 79:\tconfig\tIP_VS_PROTO_TCP\n 80:\t\tbool \"TCP load balancing support\"\n 81:\t\thelp\n 82:\t\t This option enables support for load balancing TCP transport\n 83:\t\t protocol. Say Y if unsure.\n 84:\t\n 85:\tconfig\tIP_VS_PROTO_UDP\n 86:\t\tbool \"UDP load balancing support\"\n 87:\t\thelp\n 88:\t\t This option enables support for load balancing UDP transport\n 89:\t\t protocol. Say Y if unsure.\n 90:\t\n 91:\tconfig\tIP_VS_PROTO_AH_ESP\n 92:\t\tdef_bool IP_VS_PROTO_ESP \|\| IP_VS_PROTO_AH\n 93:\t\n 94:\tconfig\tIP_VS_PROTO_ESP\n" }
13/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 24174 output: 42 thoughts: 268 Thoughts: My Analysis of the IP Virtual Server Changes Okay, let's break this down. It looks like the core of the IP Virtual Server functionality (`IP_VS`) hinges on the underlying network infrastructure (`INET`) and the netfilter framework (`NETFILTER`). Makes sense. And we have specific support modules: `IP_VS_PROTO_TCP`, which I'm assuming handles TCP load balancing – standard stuff – and `IP_VS_FTP`, which provides that crucial FTP helper functionality. Got it. Now, the interesting part: pinpointing the modifications. It seems a few functions are getting some attention. Firstly, `ip_vs_core.c` has seen some tweaks. Specifically, there's a `static inline` function called `ip_vs_conn_secure_tcp_flags`, and it's being used by a number of other functions, which are `ip_vs_sched_persist`, `ip_vs_schedule`, `ip_vs_leave`, and `ip_vs_new_conn_out`. I'll have to investigate how that inline function affects them. Then, `ip_vs_ftp.c` has these two new functions, `ip_vs_ftp_out` and `ip_vs_ftp_in`. Makes sense to have separate functions for inbound and outbound FTP connections. Finally, in `ip_vs_proto_tcp.c`, there's `set_tcp_state`, and there is also a comment about `tcp_timeout_change`. Wait... I see that `set_tcp_state` is declared as `static`. Since it's marked as static, I'm going to have to check within the same source file for any usage, otherwise there will be no way to tell how the function is used.
14/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "set_tcp_state", "PathPrefix": "net/netfilter/ipvs/ip_vs_proto_tcp.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_proto_tcp.c=449=static void tcp_timeout_change(struct ip_vs_proto_data pd, int flags)\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-455-\t memory pressure kicks in). Per-service hardening is now carried\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:456:\t * by IP_VS_CONN_F_SECURE_TCP on each connection (set_tcp_state).\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-457-\t /\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c=474=static inline void\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:475:set_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp,\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-476-\t int direction, struct tcphdr th)\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c=552=tcp_state_transition(struct ip_vs_conn *cp, int direction,\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-563-\tspin_lock_bh(\u0026cp-\u003elock);\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:564:\tset_tcp_state(pd, cp, direction, th);\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-565-\tspin_unlock_bh(\u0026cp-\u003elock);\n" }
15/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 25293 output: 42 thoughts: 47 Thoughts: Analyzing TCP State Transitions Okay, so `set_tcp_state` is a `static inline void` function, which is exactly what I expected. Now, it's called by `tcp_state_transition`, and I need to understand how these state changes are actually triggered. Time to check who's calling `tcp_state_transition` itself. That will give me a better picture of the overall flow and the specific scenarios driving those TCP state transitions. Let's see what the call graph reveals.
16/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "tcp_state_transition", "PathPrefix": "net/netfilter/ipvs/ip_vs_proto_tcp.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_proto_tcp.c=551=static void\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:552:tcp_state_transition(struct ip_vs_conn cp, int direction,\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-553-\t\t const struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c=684=struct ip_vs_protocol ip_vs_protocol_tcp = {\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-700-\t.state_name =\t\ttcp_state_name,\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:701:\t.state_transition =\ttcp_state_transition,\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-702-\t.app_conn_bind =\ttcp_app_conn_bind,\n" }
17/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 25756 output: 31 thoughts: 114 Thoughts: Analyzing the TCP State Transition Function Okay, so `tcp_state_transition` is static, which is interesting, but it's not inlined, which raises a flag. I need to figure out exactly how it's being used. It looks like `tcp_state_transition` is assigned to `.state_transition` – a function pointer within the `struct ip_vs_protocol`. This is key. Since `.state_transition` is a function pointer, the compiler cannot completely inline `tcp_state_transition`. It will definitely be present as a distinct function symbol in the vmlinux image or the `ip_vs.ko` kernel module. That's good to know. Now, the next step is to understand where and how that function pointer is being called. Let's trace all the callers of `.state_transition`. That's where the real insights will come from.
18/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "state_transition", "PathPrefix": "net/netfilter/ipvs/" } Results: { "Output": "net/netfilter/ipvs/ip_vs_core.c=405=ip_vs_set_state(struct ip_vs_conn cp, int direction,\n--\nnet/netfilter/ipvs/ip_vs_core.c-408-{\nnet/netfilter/ipvs/ip_vs_core.c:409:\tif (likely(pd-\u003epp-\u003estate_transition))\nnet/netfilter/ipvs/ip_vs_core.c:410:\t\tpd-\u003epp-\u003estate_transition(cp, direction, skb, pd, iph_len);\nnet/netfilter/ipvs/ip_vs_core.c-411-}\n--\nnet/netfilter/ipvs/ip_vs_proto_ah_esp.c=115=struct ip_vs_protocol ip_vs_protocol_ah = {\n--\nnet/netfilter/ipvs/ip_vs_proto_ah_esp.c-126-\t.dnat_handler =\t\tNULL,\nnet/netfilter/ipvs/ip_vs_proto_ah_esp.c:127:\t.state_transition =\tNULL,\nnet/netfilter/ipvs/ip_vs_proto_ah_esp.c-128-\t.register_app =\t\tNULL,\n--\nnet/netfilter/ipvs/ip_vs_proto_ah_esp.c=137=struct ip_vs_protocol ip_vs_protocol_esp = {\n--\nnet/netfilter/ipvs/ip_vs_proto_ah_esp.c-148-\t.dnat_handler =\t\tNULL,\nnet/netfilter/ipvs/ip_vs_proto_ah_esp.c:149:\t.state_transition =\tNULL,\nnet/netfilter/ipvs/ip_vs_proto_ah_esp.c-150-\t.register_app =\t\tNULL,\n--\nnet/netfilter/ipvs/ip_vs_proto_sctp.c=465=static void\nnet/netfilter/ipvs/ip_vs_proto_sctp.c:466:sctp_state_transition(struct ip_vs_conn cp, int direction,\nnet/netfilter/ipvs/ip_vs_proto_sctp.c-467-\t\tconst struct sk_buff skb, struct ip_vs_proto_data pd,\n--\nnet/netfilter/ipvs/ip_vs_proto_sctp.c=567=struct ip_vs_protocol ip_vs_protocol_sctp = {\n--\nnet/netfilter/ipvs/ip_vs_proto_sctp.c-583-\t.state_name\t= sctp_state_name,\nnet/netfilter/ipvs/ip_vs_proto_sctp.c:584:\t.state_transition = sctp_state_transition,\nnet/netfilter/ipvs/ip_vs_proto_sctp.c-585-\t.app_conn_bind\t= sctp_app_conn_bind,\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c=551=static void\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:552:tcp_state_transition(struct ip_vs_conn cp, int direction,\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-553-\t\t const struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c=684=struct ip_vs_protocol ip_vs_protocol_tcp = {\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-700-\t.state_name =\t\ttcp_state_name,\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:701:\t.state_transition =\ttcp_state_transition,\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-702-\t.app_conn_bind =\ttcp_app_conn_bind,\n--\nnet/netfilter/ipvs/ip_vs_proto_udp.c=416=static void\nnet/netfilter/ipvs/ip_vs_proto_udp.c:417:udp_state_transition(struct ip_vs_conn cp, int direction,\nnet/netfilter/ipvs/ip_vs_proto_udp.c-418-\t\t const struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_proto_udp.c=448=struct ip_vs_protocol ip_vs_protocol_udp = {\n--\nnet/netfilter/ipvs/ip_vs_proto_udp.c-461-\t.dnat_handler =\t\tudp_dnat_handler,\nnet/netfilter/ipvs/ip_vs_proto_udp.c:462:\t.state_transition =\tudp_state_transition,\nnet/netfilter/ipvs/ip_vs_proto_udp.c-463-\t.state_name =\t\tudp_state_name,\n" }
19/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 27360 output: 64 thoughts: 82 Thoughts: Examining the IPVS Core Functions Okay, let's dive into `ip_vs_core.c`. I need to confirm something about those core IPVS functions. Specifically, I'm interested in `ip_vs_sched_persist`, `ip_vs_schedule`, `ip_vs_leave`, and `ip_vs_new_conn_out`. I'm pretty sure I know the answer, but I want to double-check their scope. Are these functions declared as `static` within the file? If not, then... well, that's crucial for understanding how they interact with other parts of the kernel. To be completely certain, I'll examine the surrounding lines of code within `net/netfilter/ipvs/ip_vs_core.c` as well. Context is always key. Gotta make sure I haven't missed anything obvious.
20/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "ip_vs_sched_persist\|ip_vs_schedule\|ip_vs_leave\|ip_vs_new_conn_out", "PathPrefix": "net/netfilter/ipvs/ip_vs_core.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_core.c=56=static inline unsigned int ip_vs_conn_secure_tcp_flags(struct ip_vs_service svc)\n--\nnet/netfilter/ipvs/ip_vs_core.c-61-\nnet/netfilter/ipvs/ip_vs_core.c:62:EXPORT_SYMBOL(register_ip_vs_scheduler);\nnet/netfilter/ipvs/ip_vs_core.c:63:EXPORT_SYMBOL(unregister_ip_vs_scheduler);\nnet/netfilter/ipvs/ip_vs_core.c-64-EXPORT_SYMBOL(ip_vs_proto_name);\n--\nnet/netfilter/ipvs/ip_vs_core.c=73=EXPORT_SYMBOL(ip_vs_get_debug_level);\nnet/netfilter/ipvs/ip_vs_core.c-74-#endif\nnet/netfilter/ipvs/ip_vs_core.c:75:EXPORT_SYMBOL(ip_vs_new_conn_out);\nnet/netfilter/ipvs/ip_vs_core.c-76-\n--\nnet/netfilter/ipvs/ip_vs_core.c=436=static struct ip_vs_conn \nnet/netfilter/ipvs/ip_vs_core.c:437:ip_vs_sched_persist(struct ip_vs_service svc,\nnet/netfilter/ipvs/ip_vs_core.c-438-\t\t struct sk_buff skb, __be16 src_port, __be16 dst_port,\n--\nnet/netfilter/ipvs/ip_vs_core.c-525-\tif (!ct \|\| !ip_vs_check_template(ct, NULL)) {\nnet/netfilter/ipvs/ip_vs_core.c:526:\t\tstruct ip_vs_scheduler sched;\nnet/netfilter/ipvs/ip_vs_core.c-527-\n--\nnet/netfilter/ipvs/ip_vs_core.c-618- 0 : scheduler can not find destination, so try bypass or\nnet/netfilter/ipvs/ip_vs_core.c:619: * return ICMP and then NF_DROP (ip_vs_leave).\nnet/netfilter/ipvs/ip_vs_core.c-620- \n--\nnet/netfilter/ipvs/ip_vs_core.c-624- or pe_data. In this case we should return NF_DROP without\nnet/netfilter/ipvs/ip_vs_core.c:625: * any attempts to send ICMP with ip_vs_leave.\nnet/netfilter/ipvs/ip_vs_core.c-626- /\nnet/netfilter/ipvs/ip_vs_core.c=627=struct ip_vs_conn \nnet/netfilter/ipvs/ip_vs_core.c:628:ip_vs_schedule(struct ip_vs_service svc, struct sk_buff skb,\nnet/netfilter/ipvs/ip_vs_core.c-629-\t struct ip_vs_proto_data pd, int ignored,\n--\nnet/netfilter/ipvs/ip_vs_core.c-633-\tstruct ip_vs_conn cp = NULL;\nnet/netfilter/ipvs/ip_vs_core.c:634:\tstruct ip_vs_scheduler sched;\nnet/netfilter/ipvs/ip_vs_core.c-635-\tstruct ip_vs_dest dest;\n--\nnet/netfilter/ipvs/ip_vs_core.c-694-\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_PERSISTENT)\nnet/netfilter/ipvs/ip_vs_core.c:695:\t\treturn ip_vs_sched_persist(svc, skb, cport, vport, ignored,\nnet/netfilter/ipvs/ip_vs_core.c-696-\t\t\t\t\t iph);\n--\nnet/netfilter/ipvs/ip_vs_core.c=758=static inline int ip_vs_addr_is_unicast(struct net net, int af,\n--\nnet/netfilter/ipvs/ip_vs_core.c-772- /\nnet/netfilter/ipvs/ip_vs_core.c:773:int ip_vs_leave(struct ip_vs_service svc, struct sk_buff skb,\nnet/netfilter/ipvs/ip_vs_core.c-774-\t\tstruct ip_vs_proto_data pd, struct ip_vs_iphdr iph)\n--\nnet/netfilter/ipvs/ip_vs_core.c=1292=static inline bool is_new_conn_expected(const struct ip_vs_conn cp,\n--\nnet/netfilter/ipvs/ip_vs_core.c-1320- /\nnet/netfilter/ipvs/ip_vs_core.c:1321:struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc,\nnet/netfilter/ipvs/ip_vs_core.c-1322-\t\t\t\t struct ip_vs_dest dest,\n" }
21/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 29011 output: 50 thoughts: 240 Thoughts: Analyzing IPVS Function Scope Okay, let's break down these IPVS functions and their visibility. I see that `ip_vs_schedule`, `ip_vs_leave`, and `ip_vs_new_conn_out` are declared as non-static functions within `net/netfilter/ipvs/ip_vs_core.c`. This means they're accessible outside of that file, which is a key point for understanding how the core scheduling and connection management works. I'm also noting that `ip_vs_sched_persist` is declared as static within `ip_vs_core.c` and is specifically called by `ip_vs_schedule`. This is a classic encapsulation technique; it suggests that `ip_vs_sched_persist` is an internal helper function, not meant for direct external access, and this makes perfect sense in maintaining the modular design of IPVS. Now, shifting gears to `net/netfilter/ipvs/ip_vs_ftp.c`, I observe that `ip_vs_ftp_out` and `ip_vs_ftp_in` are static. This makes sense from an implementation standpoint as these are FTP specific handlers. This enforces the isolation of FTP-specific logic. Next, peering into `net/netfilter/ipvs/ip_vs_proto_tcp.c`, I see a static function named `tcp_state_transition` is registered as `.state_transition`. Further, `set_tcp_state` is static inline within `tcp_state_transition`. This is clever: the static declaration of `tcp_state_transition` limits its scope, making it an internal detail of TCP connection tracking, while `set_tcp_state` leverages inlining for potential performance optimization within that state transition function, and the inline nature provides additional compile time benefits. Now, let me go ahead and take a closer look at what's happening within `ip_vs_ftp_in` and `ip_vs_ftp_out` inside `ip_vs_ftp.c`. I need to figure out what functionality they are responsible for.
22/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "ip_vs_ftp_in\|ip_vs_ftp_out", "PathPrefix": "net/netfilter/ipvs/ip_vs_ftp.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_ftp.c=76=static int\nnet/netfilter/ipvs/ip_vs_ftp.c:77:ip_vs_ftp_init_conn(struct ip_vs_app app, struct ip_vs_conn cp)\nnet/netfilter/ipvs/ip_vs_ftp.c-78-{\n--\nnet/netfilter/ipvs/ip_vs_ftp.c=96=static int ip_vs_ftp_get_addrport(char data, char data_limit,\n--\nnet/netfilter/ipvs/ip_vs_ftp.c-247- /\nnet/netfilter/ipvs/ip_vs_ftp.c:248:static int ip_vs_ftp_out(struct ip_vs_app app, struct ip_vs_conn cp,\nnet/netfilter/ipvs/ip_vs_ftp.c-249-\t\t\t struct sk_buff skb, int diff,\n--\nnet/netfilter/ipvs/ip_vs_ftp.c-418- /\nnet/netfilter/ipvs/ip_vs_ftp.c:419:static int ip_vs_ftp_in(struct ip_vs_app app, struct ip_vs_conn cp,\nnet/netfilter/ipvs/ip_vs_ftp.c-420-\t\t\tstruct sk_buff skb, int diff,\n--\nnet/netfilter/ipvs/ip_vs_ftp.c=560=static struct ip_vs_app ip_vs_ftp = {\n--\nnet/netfilter/ipvs/ip_vs_ftp.c-565-\t.incs_list =\tLIST_HEAD_INIT(ip_vs_ftp.incs_list),\nnet/netfilter/ipvs/ip_vs_ftp.c:566:\t.init_conn =\tip_vs_ftp_init_conn,\nnet/netfilter/ipvs/ip_vs_ftp.c-567-\t.done_conn =\tip_vs_ftp_done_conn,\n--\nnet/netfilter/ipvs/ip_vs_ftp.c-569-\t.unbind_conn =\tNULL,\nnet/netfilter/ipvs/ip_vs_ftp.c:570:\t.pkt_out =\tip_vs_ftp_out,\nnet/netfilter/ipvs/ip_vs_ftp.c:571:\t.pkt_in =\tip_vs_ftp_in,\nnet/netfilter/ipvs/ip_vs_ftp.c-572-};\n--\nnet/netfilter/ipvs/ip_vs_ftp.c-576- /\nnet/netfilter/ipvs/ip_vs_ftp.c:577:static int __net_init __ip_vs_ftp_init(struct net net)\nnet/netfilter/ipvs/ip_vs_ftp.c-578-{\n--\nnet/netfilter/ipvs/ip_vs_ftp.c=616=static struct pernet_operations ip_vs_ftp_ops = {\nnet/netfilter/ipvs/ip_vs_ftp.c:617:\t.init = __ip_vs_ftp_init,\nnet/netfilter/ipvs/ip_vs_ftp.c-618-\t.exit = __ip_vs_ftp_exit,\n--\nnet/netfilter/ipvs/ip_vs_ftp.c-620-\nnet/netfilter/ipvs/ip_vs_ftp.c:621:static int __init ip_vs_ftp_init(void)\nnet/netfilter/ipvs/ip_vs_ftp.c-622-{\n--\nnet/netfilter/ipvs/ip_vs_ftp.c=630=static void __exit ip_vs_ftp_exit(void)\n--\nnet/netfilter/ipvs/ip_vs_ftp.c-637-\nnet/netfilter/ipvs/ip_vs_ftp.c:638:module_init(ip_vs_ftp_init);\nnet/netfilter/ipvs/ip_vs_ftp.c-639-module_exit(ip_vs_ftp_exit);\n" }
23/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 30792 output: 42 thoughts: 271 Thoughts: My Line of Reasoning Okay, so even if a function is technically static, if it's referenced through something like a struct operation or a function pointer, it has to have a symbol in the symbol table. It's not inlined, right? So, specifically, `ip_vs_ftp_out` and `ip_vs_ftp_in` are function pointers within the `ip_vs_ftp` struct, mapped to `.pkt_out` and `.pkt_in`, meaning they definitely have symbols. The same logic holds for `tcp_state_transition` – it's assigned to `.state_transition`, thus having a symbol. Now, looking at `ip_vs_core.c`, I need to make sure I understand the scope of the symbols. `ip_vs_schedule` is exported globally; that's straightforward. `ip_vs_sched_persist`, while static, is called by `ip_vs_schedule`, so I can trace it. `ip_vs_leave` is global as well. Finally, `ip_vs_new_conn_out` is also exported using `EXPORT_SYMBOL`, making it visible. Now, I'm thinking about how the `IP_VS_SVC_F_SECURE_TCP` flag is configured from user space. I need to understand if the user space flags are provided directly or if any masking is happening to prevent unwanted configurations, especially concerning security. I should check `ip_vs_ctl.c` to look at the process. Let me pull that up.
24/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "ip_vs_copy_service", "PathPrefix": "net/netfilter/ipvs/ip_vs_ctl.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_ctl.c=3622=static void\nnet/netfilter/ipvs/ip_vs_ctl.c:3623:ip_vs_copy_service(struct ip_vs_service_entry dst, struct ip_vs_service src)\nnet/netfilter/ipvs/ip_vs_ctl.c-3624-{\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=3645=__ip_vs_get_service_entries(struct netns_ipvs ipvs,\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3667-\t\t\tmemset(\u0026entry, 0, sizeof(entry));\nnet/netfilter/ipvs/ip_vs_ctl.c:3668:\t\t\tip_vs_copy_service(\u0026entry, svc);\nnet/netfilter/ipvs/ip_vs_ctl.c-3669-\t\t\tif (copy_to_user(\u0026uptr-\u003eentrytable[count],\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=3782=do_ip_vs_get_ctl(struct sock sk, int cmd, void __user user, int len)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3906-\t\tif (svc) {\nnet/netfilter/ipvs/ip_vs_ctl.c:3907:\t\t\tip_vs_copy_service(entry, svc);\nnet/netfilter/ipvs/ip_vs_ctl.c-3908-\t\t\tif (copy_to_user(user, entry, sizeof(*entry)) != 0)\n" }
25/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 31863 output: 45 thoughts: 29 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience: Analyzing the IPVS GENL Interface Okay, so I need to dig into the IPVS GENL interface, specifically the command parsing and setting functions. My first stop should be either `ip_vs_genl_set_cmd` or `ip_vs_genl_parse_service`. Given my current understanding of the architecture, I need to understand how the commands are handled and how the service parameters are validated and set. I'm leaning toward checking the `_set_cmd` first as that might give a more broad overview, but it might just be a wrapper. I expect `_parse_service` would be more specific to interpreting and sanity checking the actual configuration details for each service entry. I'll probably need to look at both in sequence, though. I want to know where the hooks for command handling are located, and how the payload is interpreted. Ultimately, I am trying to identify a potential vulnerability or optimization opportunity within the GENL command structure.
26/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "ip_vs_genl_parse_service", "PathPrefix": "net/netfilter/ipvs/ip_vs_ctl.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_ctl.c=4206=static bool ip_vs_is_af_valid(int af)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-4216-\nnet/netfilter/ipvs/ip_vs_ctl.c:4217:static int ip_vs_genl_parse_service(struct netns_ipvs ipvs,\nnet/netfilter/ipvs/ip_vs_ctl.c-4218-\t\t\t\t struct ip_vs_service_user_kern usvc,\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=4296=static struct ip_vs_service ip_vs_genl_find_service(struct netns_ipvs ipvs,\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-4302-\nnet/netfilter/ipvs/ip_vs_ctl.c:4303:\tret = ip_vs_genl_parse_service(ipvs, \u0026usvc, nla, false, \u0026svc);\nnet/netfilter/ipvs/ip_vs_ctl.c-4304-\treturn ret ? ERR_PTR(ret) : svc;\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=4685=static int ip_vs_genl_set_cmd(struct sk_buff skb, struct genl_info info)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-4718-\trcu_read_lock();\nnet/netfilter/ipvs/ip_vs_ctl.c:4719:\tret = ip_vs_genl_parse_service(ipvs, \u0026usvc,\nnet/netfilter/ipvs/ip_vs_ctl.c-4720-\t\t\t\t info-\u003eattrs[IPVS_CMD_ATTR_SERVICE],\n" }
27/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 32642 output: 44 thoughts: 27 Thoughts: Here's a summary of my thought process, as if I were the one thinking it: Diving into ip_vs_ctl.c: Parsing Services with ip_vs_genl_parse_service Okay, so I need to understand how IPVS handles parsing service-related commands, right? Time to dig into the code. Specifically, I'm going to focus my attention on `ip_vs_genl_parse_service` within `ip_vs_ctl.c`. This function name gives a clear indication it's handling the Genl-based interface and parsing service configurations. Knowing this, I expect to see the code that takes incoming Netlink messages, decodes the service parameters, and validates them. I'm keen to see the structure definitions used to represent the service (port, protocol, address, etc.) and also look at how it might handle things like flag parsing for options. I'll need to pay close attention to the error handling within this function – how are invalid or malformed requests handled? Are there specific error codes being used, and if so, how are they communicated back to the userspace tool? I want to see if the implementation takes any security considerations in validating inputs to avoid potential vulnerabilities.
28/2	2026/09/12 02:36	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_ctl.c", "FirstLine": 4217, "LineCount": 50 } Results: { "Contents": "4217:\tstatic int ip_vs_genl_parse_service(struct netns_ipvs ipvs,\n4218:\t\t\t\t\t struct ip_vs_service_user_kern usvc,\n4219:\t\t\t\t\t struct nlattr nla, bool full_entry,\n4220:\t\t\t\t\t struct ip_vs_service ret_svc)\n4221:\t{\n4222:\t\tstruct nlattr attrs[IPVS_SVC_ATTR_MAX + 1];\n4223:\t\tstruct nlattr nla_af, nla_port, nla_fwmark, nla_protocol, nla_addr;\n4224:\t\tstruct ip_vs_service svc;\n4225:\t\n4226:\t\t/* Parse mandatory identifying service fields first /\n4227:\t\tif (nla == NULL \|\|\n4228:\t\t nla_parse_nested_deprecated(attrs, IPVS_SVC_ATTR_MAX, nla, ip_vs_svc_policy, NULL))\n4229:\t\t\treturn -EINVAL;\n4230:\t\n4231:\t\tnla_af\t\t= attrs[IPVS_SVC_ATTR_AF];\n4232:\t\tnla_protocol\t= attrs[IPVS_SVC_ATTR_PROTOCOL];\n4233:\t\tnla_addr\t= attrs[IPVS_SVC_ATTR_ADDR];\n4234:\t\tnla_port\t= attrs[IPVS_SVC_ATTR_PORT];\n4235:\t\tnla_fwmark\t= attrs[IPVS_SVC_ATTR_FWMARK];\n4236:\t\n4237:\t\tif (!(nla_af \u0026\u0026 (nla_fwmark \|\| (nla_port \u0026\u0026 nla_protocol \u0026\u0026 nla_addr))))\n4238:\t\t\treturn -EINVAL;\n4239:\t\n4240:\t\tmemset(usvc, 0, sizeof(usvc));\n4241:\t\n4242:\t\tusvc-\u003eaf = nla_get_u16(nla_af);\n4243:\t\tif (!ip_vs_is_af_valid(usvc-\u003eaf))\n4244:\t\t\treturn -EAFNOSUPPORT;\n4245:\t\n4246:\t\tif (nla_fwmark) {\n4247:\t\t\tusvc-\u003eprotocol = IPPROTO_TCP;\n4248:\t\t\tusvc-\u003efwmark = nla_get_u32(nla_fwmark);\n4249:\t\t} else {\n4250:\t\t\tusvc-\u003eprotocol = nla_get_u16(nla_protocol);\n4251:\t\t\tnla_memcpy(\u0026usvc-\u003eaddr, nla_addr, sizeof(usvc-\u003eaddr));\n4252:\t\t\tusvc-\u003eport = nla_get_be16(nla_port);\n4253:\t\t\tusvc-\u003efwmark = 0;\n4254:\t\t}\n4255:\t\n4256:\t\tif (usvc-\u003efwmark)\n4257:\t\t\tsvc = __ip_vs_svc_fwm_find(ipvs, usvc-\u003eaf, usvc-\u003efwmark);\n4258:\t\telse\n4259:\t\t\tsvc = __ip_vs_service_find(ipvs, usvc-\u003eaf, usvc-\u003eprotocol,\n4260:\t\t\t\t\t\t \u0026usvc-\u003eaddr, usvc-\u003eport);\n4261:\t\tret_svc = svc;\n4262:\t\n4263:\t\t/ If a full entry was requested, check for the additional fields /\n4264:\t\tif (full_entry) {\n4265:\t\t\tstruct nlattr nla_sched, nla_flags, nla_pe, nla_timeout,\n4266:\t\t\t\t nla_netmask;\n" }
29/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 33944 output: 44 thoughts: 19 Thoughts: Okay, let's dive into this `ip_vs_genl_parse_service` function and see what it's all about. I'm curious to understand its implementation, especially how it's parsing service-related information within the context of IP Virtual Server (IPVS) and the generic netlink interface. I'm expecting to find details on how it handles attributes, data structures, and the overall logic for configuring and managing services. I'm really looking forward to dissecting the specific data structures and attribute handling within this function to see how it fits into the broader IPVS architecture. I'm keen to get a solid grasp of how this function contributes to IPVS's operation.
30/2	2026/09/12 02:36	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_ctl.c", "FirstLine": 4267, "LineCount": 35 } Results: { "Contents": "4267:\t\t\tstruct ip_vs_flags flags;\n4268:\t\n4269:\t\t\tnla_sched = attrs[IPVS_SVC_ATTR_SCHED_NAME];\n4270:\t\t\tnla_pe = attrs[IPVS_SVC_ATTR_PE_NAME];\n4271:\t\t\tnla_flags = attrs[IPVS_SVC_ATTR_FLAGS];\n4272:\t\t\tnla_timeout = attrs[IPVS_SVC_ATTR_TIMEOUT];\n4273:\t\t\tnla_netmask = attrs[IPVS_SVC_ATTR_NETMASK];\n4274:\t\n4275:\t\t\tif (!(nla_sched \u0026\u0026 nla_flags \u0026\u0026 nla_timeout \u0026\u0026 nla_netmask))\n4276:\t\t\t\treturn -EINVAL;\n4277:\t\n4278:\t\t\tnla_memcpy(\u0026flags, nla_flags, sizeof(flags));\n4279:\t\n4280:\t\t\t/* prefill flags from service if it already exists /\n4281:\t\t\tif (svc)\n4282:\t\t\t\tusvc-\u003eflags = svc-\u003eflags;\n4283:\t\n4284:\t\t\t/ set new flags from userland /\n4285:\t\t\tusvc-\u003eflags = (usvc-\u003eflags \u0026 ~flags.mask) \|\n4286:\t\t\t\t (flags.flags \u0026 flags.mask);\n4287:\t\t\tusvc-\u003esched_name = nla_data(nla_sched);\n4288:\t\t\tusvc-\u003epe_name = nla_pe ? nla_data(nla_pe) : NULL;\n4289:\t\t\tusvc-\u003etimeout = nla_get_u32(nla_timeout);\n4290:\t\t\tusvc-\u003enetmask = nla_get_be32(nla_netmask);\n4291:\t\t}\n4292:\t\n4293:\t\treturn 0;\n4294:\t}\n4295:\t\n4296:\tstatic struct ip_vs_service ip_vs_genl_find_service(struct netns_ipvs ipvs,\n4297:\t\t\t\t\t\t\t struct nlattr nla)\n4298:\t{\n4299:\t\tstruct ip_vs_service_user_kern usvc;\n4300:\t\tstruct ip_vs_service *svc;\n4301:\t\tint ret;\n" }
31/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 34760 output: 45 thoughts: 146 Thoughts: My Assessment of IPVS Service Flag Manipulation Okay, so I'm looking at how service flags in IPVS are handled, and it seems like `flags.mask` and `flags.flags` are entirely controlled by the user. That's a key observation. The core operation, `usvc->flags = (usvc->flags & ~flags.mask) \| (flags.flags & flags.mask);`, is where the user's input directly modifies the service flags. This means a user in userland can manipulate things like `IP_VS_SVC_F_SECURE_TCP` through the Netlink generic commands `IPVS_CMD_NEW_SERVICE` or `IPVS_CMD_SET_SERVICE`. And hold on, setsockopt `IP_VS_SO_SET_ADD` uses `struct ip_vs_service_user`, which also exposes that `flags` field. This confirms my suspicion that it’s another avenue for user control. Given this, I should probably take a closer look at `ip_vs_copy_usvc_compat` to see exactly how these user-provided flags are interpreted and validated, and make sure that any legacy compatibility methods don't introduce vulnerabilities.
32/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "ip_vs_copy_usvc_compat", "PathPrefix": "net/netfilter/ipvs/ip_vs_ctl.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_ctl.c=3422=union ip_vs_set_arglen {\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3436-\nnet/netfilter/ipvs/ip_vs_ctl.c:3437:static void ip_vs_copy_usvc_compat(struct ip_vs_service_user_kern usvc,\nnet/netfilter/ipvs/ip_vs_ctl.c-3438-\t\t\t\t struct ip_vs_service_user usvc_compat)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=3472=do_ip_vs_set_ctl(struct sock sk, int cmd, sockptr_t ptr, unsigned int len)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3539-\t structs to extended internal versions */\nnet/netfilter/ipvs/ip_vs_ctl.c:3540:\tip_vs_copy_usvc_compat(\u0026usvc, usvc_compat);\nnet/netfilter/ipvs/ip_vs_ctl.c-3541-\tip_vs_copy_udest_compat(\u0026udest, udest_compat);\n" }
33/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 35534 output: 44 thoughts: 13 Thoughts: Okay, here's my interpretation of that thought process, summarized as you requested: Understanding ip_vs_copy_usvc_compat Alright, let's break this down. From what I can gather, we're talking about `ip_vs_copy_usvc_compat`. Now, knowing how `ip_vs` (IP Virtual Server) works, this must relate to a compatibility layer or module, possibly within the user-space interactions. The "copy" part likely refers to data transfer or some form of state replication between different components, and "usvc_compat" hints at legacy or compatibility with older User-Space Virtual Connection (USVC) methods or protocols, maybe even emulating some behavior for backwards-compatibility. This probably comes into play with a specific, maybe older, system setup. I'd need more context to be sure. I can hypothesize that this module could be there so that the new IPVS system will work with older software.
34/2	2026/09/12 02:36	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_ctl.c", "FirstLine": 3437, "LineCount": 20 } Results: { "Contents": "3437:\tstatic void ip_vs_copy_usvc_compat(struct ip_vs_service_user_kern usvc,\n3438:\t\t\t\t\t struct ip_vs_service_user usvc_compat)\n3439:\t{\n3440:\t\tmemset(usvc, 0, sizeof(usvc));\n3441:\t\n3442:\t\tusvc-\u003eaf\t\t= AF_INET;\n3443:\t\tusvc-\u003eprotocol\t\t= usvc_compat-\u003eprotocol;\n3444:\t\tusvc-\u003eaddr.ip\t\t= usvc_compat-\u003eaddr;\n3445:\t\tusvc-\u003eport\t\t= usvc_compat-\u003eport;\n3446:\t\tusvc-\u003efwmark\t\t= usvc_compat-\u003efwmark;\n3447:\t\n3448:\t\t/ Deep copy of sched_name is not needed here /\n3449:\t\tusvc-\u003esched_name\t= usvc_compat-\u003esched_name;\n3450:\t\n3451:\t\tusvc-\u003eflags\t\t= usvc_compat-\u003eflags;\n3452:\t\tusvc-\u003etimeout\t\t= usvc_compat-\u003etimeout;\n3453:\t\tusvc-\u003enetmask\t\t= usvc_compat-\u003enetmask;\n3454:\t}\n3455:\t\n3456:\tstatic void ip_vs_copy_udest_compat(struct ip_vs_dest_user_kern udest,\n" }
35/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 36169 output: 35 thoughts: 461 Thoughts: Vulnerability Assessment: IPVS Secure TCP Flag Okay, so I've been digging into the IPVS code, and a potential vulnerability has jumped out at me. Both genl netlink and sockopt offer the ability for userland to set `flags`. Specifically, they can set `IP_VS_SVC_F_SECURE_TCP`! Now, the sync daemon seems to handle `IP_VS_CONN_F_BACKUP_MASK`, which, importantly, includes `IP_VS_CONN_F_SECURE_TCP`. Looking at the connection lifecycle, functions like `ip_vs_schedule`, `ip_vs_sched_persist`, `ip_vs_leave`, and `ip_vs_new_conn_out` all pass `ip_vs_conn_secure_tcp_flags(svc)` to the connection flags when connections are established to the service. Then, the real kicker: in `set_tcp_state` and `tcp_state_transition`, if `IP_VS_CONN_F_SECURE_TCP` is set, it uses the `tcp_states_dos` table instead of the usual `pd->tcp_state_table` for TCP state transitions. This has the potential to bypass normal flow control. On top of that, this flag is propagated for FTP helper connections too, in `ip_vs_ftp_in` and `ip_vs_ftp_out`. Given that this is all clearly reachable through standard networking and the use of netlink/sockopts within virtualized environments, and directly affects core IPVS load balancing logic, this looks like a prime candidate for fuzzing. The potential impact is significant, and the attack surface is relatively accessible. `WorthFuzzing=true`, definitely. Now, let's nail down the required configurations. We'll need `IP_VS` from net/netfilter/ipvs/Kconfig, which depends on `INET` and `NETFILTER`. We'll also need `IP_VS_PROTO_TCP`, which is "TCP load balancing support", and is necessary for `ip_vs_proto_tcp.c`. And since FTP is involved, we will need `IP_VS_FTP`, which is the "FTP protocol helper", and has its own dependencies: `IP_VS_PROTO_TCP`, `NF_CONNTRACK`, `NF_NAT`, and `NF_CONNTRACK_FTP`. This will ensure `ip_vs_ftp.c` is enabled. I need to quickly scan other relevant Kconfig files like `net/netfilter/Kconfig` and `net/Kconfig` for any other dependencies or configurations that might be relevant to IPVS, just to be thorough.
36/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "source \"net/netfilter/ipvs/Kconfig\"", "PathPrefix": "net/" } Results: { "Output": "net/netfilter/Kconfig=1662=source \"net/netfilter/ipset/Kconfig\"\nnet/netfilter/Kconfig-1663-\nnet/netfilter/Kconfig:1664:source \"net/netfilter/ipvs/Kconfig\"\n" }
37/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 37319 output: 35 thoughts: 747 Thoughts: My IPVS Focus Symbol Analysis Okay, let's break this down systematically. First, I need to make sure IPVS is even enabled. Looking at `net/netfilter/ipvs/Kconfig`, lines 5-10, confirms that `IP_VS` is indeed a menuconfig option, depending on `INET` and `NETFILTER` and either `NF_CONNTRACK` or its disabled state. That's good to know, and the necessary configs to enable are `IP_VS`, `IP_VS_PROTO_TCP`, and `IP_VS_FTP`. Now, the important part: defining the `FocusSymbols`. Remembering the instructions, I need to pinpoint the right functions to guide the fuzzer. I need to avoid ubiquitous functions like memory allocators or lock primitives – those are noise. I want specific feature logic or entry points for the IPVS subsystem. And I have to be careful with static inline functions. Since they don't have distinct symbols, I need to identify non-static caller functions in the .c files that exercise those static helpers. So, let's dive into the modified functions. Scanning through the files, I see: 1. In `net/netfilter/ipvs/ip_vs_core.c`, `ip_vs_conn_secure_tcp_flags` is static inline. Its callers in the same file include `ip_vs_sched_persist`, which is also static and called by `ip_vs_schedule`. I should avoid the static function. Other callers include `ip_vs_schedule`, `ip_vs_leave`, and `ip_vs_new_conn_out`, all of which are non-static and good candidates as targets. 2. In `net/netfilter/ipvs/ip_vs_proto_tcp.c`, `set_tcp_state` is another static inline function. Its caller is `tcp_state_transition`, which, crucially, is static as well. However, I see `tcp_state_transition` is assigned to the `.state_transition` function pointer in the `ip_vs_protocol_tcp` structure. This means `tcp_state_transition` won't be inlined. That's excellent! I can use `tcp_state_transition` as a `FocusSymbol` since it's a defined symbol. Where is it being called? Looking back at the `ip_vs_core.c` file, `ip_vs_set_state` calls `pd->pp->state_transition(...)`. Therefore, I need to review and potentially add `ip_vs_set_state` to the `FocusSymbols` list, too.
38/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "ip_vs_set_state", "PathPrefix": "net/netfilter/ipvs/" } Results: { "Output": "net/netfilter/ipvs/ip_vs_core.c=404=static inline void\nnet/netfilter/ipvs/ip_vs_core.c:405:ip_vs_set_state(struct ip_vs_conn cp, int direction,\nnet/netfilter/ipvs/ip_vs_core.c-406-\t\tconst struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_core.c=773=int ip_vs_leave(struct ip_vs_service svc, struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_core.c-816-\t\t/* set state /\nnet/netfilter/ipvs/ip_vs_core.c:817:\t\tip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd, iph-\u003elen);\nnet/netfilter/ipvs/ip_vs_core.c-818-\n--\nnet/netfilter/ipvs/ip_vs_core.c=1453=handle_response(int af, struct sk_buff skb, struct ip_vs_proto_data pd,\n--\nnet/netfilter/ipvs/ip_vs_core.c-1503-\tip_vs_out_stats(cp, skb);\nnet/netfilter/ipvs/ip_vs_core.c:1504:\tip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd, iph-\u003elen);\nnet/netfilter/ipvs/ip_vs_core.c-1505-\tskb-\u003eipvs_property = 1;\n--\nnet/netfilter/ipvs/ip_vs_core.c=2111=ip_vs_in_hook(void priv, struct sk_buff skb, const struct nf_hook_state state)\n--\nnet/netfilter/ipvs/ip_vs_core.c-2266-\tip_vs_in_stats(cp, skb);\nnet/netfilter/ipvs/ip_vs_core.c:2267:\tip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd, iph.len);\nnet/netfilter/ipvs/ip_vs_core.c-2268-\tif (cp-\u003epacket_xmit)\n" }
39/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 39294 output: 42 thoughts: 437 Thoughts: My Analysis of IPVS Core Functions Okay, let's break this down. My initial observation is that `tcp_state_transition` gets triggered through `pd->pp->state_transition` within `ip_vs_set_state`, which is, of course, present in `handle_response`, `ip_vs_in_hook`, and `ip_vs_leave`. Seems straightforward enough. Now, I'm pivoting to `net/netfilter/ipvs/ip_vs_ftp.c`. I need to differentiate `ip_vs_ftp_out` and `ip_vs_ftp_in`. It looks like these are static functions, accessed via function pointers in `struct ip_vs_app ip_vs_ftp` (`.pkt_out`, `.pkt_in`), so they should be distinct and not a problem. The real question here is whether `ip_vs_sched_persist` could be inlined. I see that it is static within `ip_vs_core.c` and is only ever called from `ip_vs_schedule`. This is interesting. `ip_vs_schedule` itself is non-static (`struct ip_vs_conn * ip_vs_schedule(...)`), as is `ip_vs_leave` and `ip_vs_new_conn_out`. So, the candidate functions to focus on are: - `ip_vs_schedule` - `ip_vs_leave` - `ip_vs_new_conn_out` - `tcp_state_transition` - `ip_vs_ftp_out` - `ip_vs_ftp_in` But what about `ip_vs_sched_persist`? Even if the compiler inlines it into `ip_vs_schedule`, analyzing `ip_vs_schedule` will cover its behavior. If it isn't inlined, then it's a great target on its own. I'll need to check the size of `ip_vs_sched_persist` to inform my final selection.
40/2	2026/09/12 02:36	tool	grepper	0m Args: { "Expression": "ip_vs_sched_persist", "PathPrefix": "net/netfilter/ipvs/ip_vs_core.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_core.c=436=static struct ip_vs_conn \nnet/netfilter/ipvs/ip_vs_core.c:437:ip_vs_sched_persist(struct ip_vs_service svc,\nnet/netfilter/ipvs/ip_vs_core.c-438-\t\t struct sk_buff skb, __be16 src_port, __be16 dst_port,\n--\nnet/netfilter/ipvs/ip_vs_core.c=628=ip_vs_schedule(struct ip_vs_service svc, struct sk_buff *skb,\n--\nnet/netfilter/ipvs/ip_vs_core.c-694-\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_PERSISTENT)\nnet/netfilter/ipvs/ip_vs_core.c:695:\t\treturn ip_vs_sched_persist(svc, skb, cport, vport, ignored,\nnet/netfilter/ipvs/ip_vs_core.c-696-\t\t\t\t\t iph);\n" }
41/2	2026/09/12 02:36	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 40503 output: 45 thoughts: 716 Thoughts: My Analysis of IPVS Code and Configuration Requirements Okay, so I'm diving into this `ip_vs` code. I've noticed `ip_vs_sched_persist` is a pretty hefty function – over 150 lines. That means the compiler might not always inline it unless it's explicitly marked `inline`. To be safe, and ensure that I cover the relevant code paths, even if the compiler doesn't inline, I need to focus on functions like `ip_vs_schedule`, `ip_vs_leave`, `ip_vs_new_conn_out`, `tcp_state_transition`, `ip_vs_ftp_in`, and `ip_vs_ftp_out` – these are the key pieces to be examined. I'll probably include `ip_vs_schedule` in the coverage as well. Now, before I go deeper into the code, I need to make sure I understand the full picture of the affected files and configuration dependencies. I've already identified the modified files: `include/uapi/linux/ip_vs.h`, `net/netfilter/ipvs/ip_vs_core.c`, `net/netfilter/ipvs/ip_vs_ftp.c`, `net/netfilter/ipvs/ip_vs_proto_tcp.c`, `tools/testing/selftests/net/netfilter/Makefile`, `tools/testing/selftests/net/netfilter/gen_tcp_probe.c`, `tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh`, and `tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c`. Good. Next, I need to nail down the configuration options needed for this to build and run correctly. I know I'm looking at `IP_VS`, `IP_VS_PROTO_TCP`, and `IP_VS_FTP`, but I need to be thorough. I don't want to make assumptions. Let's check for dependencies, starting with `IP_VS_FTP`. Okay, I'm checking the Kconfig for `IP_VS_FTP`, and it's clear: `depends on IP_VS_PROTO_TCP && NF_CONNTRACK && NF_NAT && NF_CONNTRACK_FTP`. Excellent! So that means I need to list not just `IP_VS_FTP`, `IP_VS_PROTO_TCP`, and `IP_VS`, but also `NF_CONNTRACK`, `NF_NAT`, and `NF_CONNTRACK_FTP`. Wait a moment, I should also check the instructions to ensure I am stripping the "CONFIG_" prefix. The instructions say to identify specific `CONFIG_` options, inspect Kconfig files and `#ifdef` guards, check `depends on` lines, and to strip the "CONFIG_" prefix. Now, let's confirm the list for `IP_VS_FTP` by looking at the Kconfig file for it. ```kconfig config IP_VS_FTP tristate "FTP protocol helper" depends on IP_VS_PROTO_TCP && NF_CONNTRACK && NF_NAT && \ NF_CONNTRACK_FTP select IP_VS_NFCT ``` So, that confirms I need `IP_VS`, `IP_VS_PROTO_TCP`, `IP_VS_FTP`, `NF_CONNTRACK`, `NF_NAT`, and `NF_CONNTRACK_FTP`. That's the correct list. Finally, I need to make sure I don't miss anything that's conditionally compiled. Let me specifically check the code in `net/netfilter/ipvs/ip_vs_proto_tcp.c` to see if `set_tcp_state` or `tcp_state_transition` is wrapped in any `#ifdef` directives. I don't want to miss a dependency.
42/2	2026/09/12 02:37	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_proto_tcp.c", "FirstLine": 470, "LineCount": 40 } Results: { "Contents": " 470:\t\t\treturn 2;\n 471:\t\treturn -1;\n 472:\t}\n 473:\t\n 474:\tstatic inline void\n 475:\tset_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp,\n 476:\t\t int direction, struct tcphdr th)\n 477:\t{\n 478:\t\tint state_idx;\n 479:\t\tint new_state = IP_VS_TCP_S_CLOSE;\n 480:\t\tint state_off = tcp_state_off[direction];\n 481:\t\tconst struct tcp_states_t table;\n 482:\t\n 483:\t\t/\n 484:\t\t Update state offset to INPUT_ONLY if necessary\n 485:\t\t * or delete NO_OUTPUT flag if output packet detected\n 486:\t\t /\n 487:\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_NOOUTPUT) {\n 488:\t\t\tif (state_off == TCP_DIR_OUTPUT)\n 489:\t\t\t\tcp-\u003eflags \u0026= ~IP_VS_CONN_F_NOOUTPUT;\n 490:\t\t\telse\n 491:\t\t\t\tstate_off = TCP_DIR_INPUT_ONLY;\n 492:\t\t}\n 493:\t\n 494:\t\tif ((state_idx = tcp_state_idx(th)) \u003c 0) {\n 495:\t\t\tIP_VS_DBG(8, \"tcp_state_idx=%d!!!\\n\", state_idx);\n 496:\t\t\tgoto tcp_state_out;\n 497:\t\t}\n 498:\t\n 499:\t\ttable = pd-\u003etcp_state_table;\n 500:\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_SECURE_TCP)\n 501:\t\t\ttable = tcp_states_dos;\n 502:\t\tnew_state = table[state_off + state_idx].next_state[cp-\u003estate];\n 503:\t\n 504:\t tcp_state_out:\n 505:\t\tif (new_state != cp-\u003estate) {\n 506:\t\t\tstruct ip_vs_dest dest = cp-\u003edest;\n 507:\t\n 508:\t\t\tIP_VS_DBG_BUF(8, \"%s %s [%c%c%c%c] c:%s:%d v:%s:%d \"\n 509:\t\t\t\t \"d:%s:%d state: %s-\u003e%s conn-\u003erefcnt:%d\\n\",\n" }
43/2	2026/09/12 02:37	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 42792 output: 239 thoughts: 187 Thoughts: Fuzzing Decision: Confirmed Okay, so I've just reviewed the setup for fuzzing this specific section of the code, and everything looks spot on. There are no preprocessor directives (#ifdefs) surrounding the `set_tcp_state` or `tcp_state_transition` functions, which is crucial for consistent analysis, and as expected, `ip_vs_proto_tcp.c` is compiled when `CONFIG_IP_VS_PROTO_TCP` is enabled. That's the baseline. Let's quickly run through the requirements. The `WorthFuzzing` flag is set to true, as it should be. The reasoning for this fuzzing target is concise and justified, which I appreciate. The `EnableConfigs` list looks accurate: we have `IP_VS`, `IP_VS_PROTO_TCP`, `IP_VS_FTP`, `NF_CONNTRACK`, `NF_NAT`, and `NF_CONNTRACK_FTP` all enabled. These are the expected prerequisites for this kind of work, ensuring the relevant code paths are active. And finally, the `FocusSymbols`: `ip_vs_schedule`, `ip_vs_leave`, `ip_vs_new_conn_out`, `tcp_state_transition`, `ip_vs_ftp_in`, and `ip_vs_ftp_out`. Those functions are exactly the critical entry points and state transition points that I'd expect to see targeted here. It all lines up perfectly. Yup, it's all clean, correct, and directly based on the code itself. The configuration and dependencies are all correctly represented. Time to call `set-results`. Let's get this fuzzing run going.
44/2	2026/09/12 02:37	tool	set-results	0m Args: { "EnableConfigs": [ "IP_VS", "IP_VS_PROTO_TCP", "IP_VS_FTP", "NF_CONNTRACK", "NF_NAT", "NF_CONNTRACK_FTP" ], "FocusSymbols": [ "ip_vs_schedule", "ip_vs_leave", "ip_vs_new_conn_out", "tcp_state_transition", "ip_vs_ftp_in", "ip_vs_ftp_out" ], "Reasoning": "The patch adds support for per-service hardened TCP table configuration via new flags IP_VS_SVC_F_SECURE_TCP and IP_VS_CONN_F_SECURE_TCP. It updates connection creation logic in IPVS core and FTP helper routines to propagate the flag, and modifies the TCP state transition machine to select the DoS-hardened TCP state table when the connection flag is set. The code path is reachable in virtualized environments via standard IPVS netlink/setsockopt configuration and network traffic.", "WorthFuzzing": true } Results: { "EnableConfigs": [ "IP_VS", "IP_VS_PROTO_TCP", "IP_VS_FTP", "NF_CONNTRACK", "NF_NAT", "NF_CONNTRACK_FTP" ], "FocusSymbols": [ "ip_vs_schedule", "ip_vs_leave", "ip_vs_new_conn_out", "tcp_state_transition", "ip_vs_ftp_in", "ip_vs_ftp_out" ], "Reasoning": "The patch adds support for per-service hardened TCP table configuration via new flags IP_VS_SVC_F_SECURE_TCP and IP_VS_CONN_F_SECURE_TCP. It updates connection creation logic in IPVS core and FTP helper routines to propagate the flag, and modifies the TCP state transition machine to select the DoS-hardened TCP state table when the connection flag is set. The code path is reachable in virtualized environments via standard IPVS netlink/setsockopt configuration and network traffic.", "WorthFuzzing": true }
45/1	2026/09/12 02:37	action	If	1m Args: { "WorthFuzzing": true } Results: null
46/2	2026/09/12 02:37	agent	kmsan-evaluator	1m Model: core Args: null Results: { "KMSANReasoning": "The patch introduces support for per-service hardened TCP state tracking (IP_VS_SVC_F_SECURE_TCP and IP_VS_CONN_F_SECURE_TCP) in IPVS. It allows connections belonging to a secure_tcp-enabled virtual service to use the existing hardened TCP state table (tcp_states_dos) rather than the default table, propagates this flag during connection creation and sync daemon handling (via IP_VS_CONN_F_BACKUP_MASK), and includes selftest utilities.\n\nAnalysis of uninitialized memory risk:\n1. Data structures \u0026 fields: The patch does not define new data structures or change the size, alignment, or padding of existing structures. It uses previously unused bit positions in existing integer fields (svc-\u003eflags and cp-\u003eflags).\n2. Initialization: Both struct ip_vs_service and struct ip_vs_conn have well-defined initialization routines (kzalloc and explicit member initialization in ip_vs_conn_new, respectively). Flags are initialized before use and propagated via standard bitwise operations on initialized variables.\n3. State lookup: The state table referenced (tcp_states_dos) is an existing, fully initialized static array of state transitions.\n4. User-space copies / info leaks: No uninitialized kernel memory or padding is exposed or copied to user space or across netlink/sockopt interfaces.\n\nAny potential defects in this patch (e.g., protocol state handling errors, synchronization or locking issues, or pointer dereferences) are functional bugs or within the scope of KASAN/LOCKDEP. There is no risk of uninitialized memory reads or information leaks detectable only by KMSAN. Therefore, a dedicated KMSAN session is not required.", "NeedsKMSAN": false } Instruction: You are an expert Linux kernel security engineer specializing in kernel memory error detectors (KASAN and KMSAN). Your job is to review the provided patch series and determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer) fuzzing session in addition to standard KASAN fuzzing. CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN: - Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable a comprehensive suite of debugging tools and sanitizers, including KASAN (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks. - KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap, or page allocations) and kernel-to-user memory info-leaks. Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN, LOCKDEP, OR OTHER STANDARD BUG DETECTORS. A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks that are detected ONLY by KMSAN. Look holistically at the patch series and surrounding code. Even if no direct uninitialized field accesses or new buffer allocations are added in the diff itself, a patch may alter control flow, bounds checking, or data length calculations in ways that change how the rest of the code operates on existing buffers (e.g. allowing uninitialized stack/heap memory to be read, copied to user space, or used in control flow). Do not hesitate to use your code access tools to inspect the surrounding code, called functions, and callers. Set NeedsKMSAN=true ONLY IF the patch introduces or modifies: 1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb attributes, ioctl output arguments, socket options, or BPF buffers) where fields or structure padding might not be fully initialized/zeroed. 2. Conditional logic or branching that depends on potentially uninitialized variables or struct fields. 3. Allocation or initialization of complex data structures where uninitialized fields could be read later in reachable code paths. 4. Bounds checks, lengths, or logic in a way that allows surrounding code to access uninitialized bytes of existing buffers. Set NeedsKMSAN=false IF: - The code changes primarily risk out-of-bounds access, array overflows, NULL pointer dereferences, locking deadlocks, or use-after-free bugs (these are already caught by KASAN, LOCKDEP, or standard bug detectors). - All stack/heap structures touched or introduced by the patch are fully zeroed or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied. - The patch does not introduce any risk of uninitialized memory usage or info-leaks. Use your code access tools to inspect the surrounding code if necessary, then provide detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch. Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: Target architecture: amd64 For your convenience, here is the diff of the changes: commit 99272cd2604c766adfa7ff72bd4a8cc0b203380b Author: syz-cluster <triage@syzkaller.com> Date: Sat Sep 12 02:35:44 2026 +0000 syz-cluster: applied patch under review diff --git a/include/uapi/linux/ip_vs.h b/include/uapi/linux/ip_vs.h index 2c37c6ac7525a..34fcfaf13cd3f 100644 --- a/include/uapi/linux/ip_vs.h +++ b/include/uapi/linux/ip_vs.h @@ -27,6 +27,7 @@ #define IP_VS_SVC_F_SCHED_SH_FALLBACK IP_VS_SVC_F_SCHED1 /* SH fallback / #define IP_VS_SVC_F_SCHED_SH_PORT IP_VS_SVC_F_SCHED2 / SH use port / +#define IP_VS_SVC_F_SECURE_TCP 0x0040 / use the hardened TCP table / / * IPVS sync daemon states @@ -89,6 +90,7 @@ #define IP_VS_CONN_F_NO_CPORT 0x0800 /* no client port set yet / #define IP_VS_CONN_F_TEMPLATE 0x1000 / template, not connection / #define IP_VS_CONN_F_ONE_PACKET 0x2000 / forward only one packet / +#define IP_VS_CONN_F_SECURE_TCP 0x0008 / use the hardened TCP table / / Initial bits allowed in backup server / #define IP_VS_CONN_F_BACKUP_MASK (IP_VS_CONN_F_FWD_MASK \| \ @@ -96,7 +98,8 @@ IP_VS_CONN_F_INACTIVE \| \ IP_VS_CONN_F_SEQ_MASK \| \ IP_VS_CONN_F_NO_CPORT \| \ - IP_VS_CONN_F_TEMPLATE \ + IP_VS_CONN_F_TEMPLATE \| \ + IP_VS_CONN_F_SECURE_TCP \ ) / Bits allowed to update in backup server / diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index ba0957798bad0..eead1b992dd96 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -52,6 +52,13 @@ #include <linux/indirect_call_wrapper.h> +/ Encode the per-service secure_tcp capability into a connection flag / +static inline unsigned int ip_vs_conn_secure_tcp_flags(struct ip_vs_service svc) +{ + return (svc->flags & IP_VS_SVC_F_SECURE_TCP) ? + IP_VS_CONN_F_SECURE_TCP : 0; +} + EXPORT_SYMBOL(register_ip_vs_scheduler); EXPORT_SYMBOL(unregister_ip_vs_scheduler); EXPORT_SYMBOL(ip_vs_proto_name); @@ -546,7 +553,9 @@ ip_vs_sched_persist(struct ip_vs_service svc, and thus param.pe_data will be destroyed * when the template expires / ct = ip_vs_conn_new(&param, dest->af, &dest->addr, dport, - IP_VS_CONN_F_TEMPLATE, dest, skb->mark); + IP_VS_CONN_F_TEMPLATE \| + ip_vs_conn_secure_tcp_flags(svc), dest, + skb->mark); if (ct == NULL) { kfree(param.pe_data); ignored = -1; @@ -567,6 +576,7 @@ ip_vs_sched_persist(struct ip_vs_service svc, flags = (svc->flags & IP_VS_SVC_F_ONEPACKET && iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0; + flags \|= ip_vs_conn_secure_tcp_flags(svc); / * Create a new connection according to the template @@ -714,6 +724,7 @@ ip_vs_schedule(struct ip_vs_service svc, struct sk_buff skb, flags = (svc->flags & IP_VS_SVC_F_ONEPACKET && iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0; + flags \|= ip_vs_conn_secure_tcp_flags(svc); /* * Create a connection entry. @@ -779,9 +790,10 @@ int ip_vs_leave(struct ip_vs_service svc, struct sk_buff skb, ip_vs_addr_is_unicast(net, svc->af, &iph->daddr)) { int ret; struct ip_vs_conn cp; - unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET && + unsigned int flags = ((svc->flags & IP_VS_SVC_F_ONEPACKET && iph->protocol == IPPROTO_UDP) ? - IP_VS_CONN_F_ONE_PACKET : 0; + IP_VS_CONN_F_ONE_PACKET : 0) \| + ip_vs_conn_secure_tcp_flags(svc); union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } }; / create a new connection entry / @@ -1350,7 +1362,9 @@ struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc, / check if template exists and points to the same dest / if (!ct \|\| !ip_vs_check_template(ct, dest)) { ct = ip_vs_conn_new(&param, dest->af, daddr, dport, - IP_VS_CONN_F_TEMPLATE, dest, 0); + IP_VS_CONN_F_TEMPLATE \| + ip_vs_conn_secure_tcp_flags(svc), + dest, 0); if (!ct) { kfree(param.pe_data); return NULL; @@ -1364,6 +1378,7 @@ struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc, / connection flags / flags = ((svc->flags & IP_VS_SVC_F_ONEPACKET) && iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0; + flags \|= ip_vs_conn_secure_tcp_flags(svc); / create connection / ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol, caddr, cport, vaddr, vport, &param); diff --git a/net/netfilter/ipvs/ip_vs_ftp.c b/net/netfilter/ipvs/ip_vs_ftp.c index b315c608fda43..73d2e79043038 100644 --- a/net/netfilter/ipvs/ip_vs_ftp.c +++ b/net/netfilter/ipvs/ip_vs_ftp.c @@ -330,7 +330,8 @@ static int ip_vs_ftp_out(struct ip_vs_app app, struct ip_vs_conn cp, 0, &cp->vaddr, port, &p); n_cp = ip_vs_conn_new(&p, cp->af, &from, port, IP_VS_CONN_F_NO_CPORT \| - IP_VS_CONN_F_NFCT, + IP_VS_CONN_F_NFCT \| + (cp->flags & IP_VS_CONN_F_SECURE_TCP), cp->dest, skb->mark); if (!n_cp) return 0; @@ -535,8 +536,9 @@ static int ip_vs_ftp_in(struct ip_vs_app app, struct ip_vs_conn cp, if (!n_cp) { n_cp = ip_vs_conn_new(&p, cp->af, &cp->daddr, htons(ntohs(cp->dport)-1), - IP_VS_CONN_F_NFCT, cp->dest, - skb->mark); + IP_VS_CONN_F_NFCT \| + (cp->flags & IP_VS_CONN_F_SECURE_TCP), + cp->dest, skb->mark); if (!n_cp) return 0; diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c index fec0e8b47b716..3b9a2c8e9a527 100644 --- a/net/netfilter/ipvs/ip_vs_proto_tcp.c +++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c @@ -451,11 +451,10 @@ static void tcp_timeout_change(struct ip_vs_proto_data pd, int flags) int on = (flags & 1); /* secure_tcp / / - FIXME: change secure_tcp to independent sysctl var - or make it per-service or per-app because it is valid - for most if not for all of the applications. Something - like "capabilities" (flags) for each object. - / + This remains the netns-wide default / global floor (e.g. when + * memory pressure kicks in). Per-service hardening is now carried + * by IP_VS_CONN_F_SECURE_TCP on each connection (set_tcp_state). + / pd->tcp_state_table = (on ? tcp_states_dos : tcp_states); } @@ -479,6 +478,7 @@ set_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp, int state_idx; int new_state = IP_VS_TCP_S_CLOSE; int state_off = tcp_state_off[direction]; + const struct tcp_states_t table; /* * Update state offset to INPUT_ONLY if necessary @@ -496,8 +496,10 @@ set_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp, goto tcp_state_out; } - new_state = - pd->tcp_state_table[state_off+state_idx].next_state[cp->state]; + table = pd->tcp_state_table; + if (cp->flags & IP_VS_CONN_F_SECURE_TCP) + table = tcp_states_dos; + new_state = table[state_off + state_idx].next_state[cp->state]; tcp_state_out: if (new_state != cp->state) { diff --git a/tools/testing/selftests/net/netfilter/Makefile b/tools/testing/selftests/net/netfilter/Makefile index f88dd4ef8d264..fad05afadd41b 100644 --- a/tools/testing/selftests/net/netfilter/Makefile +++ b/tools/testing/selftests/net/netfilter/Makefile @@ -20,6 +20,7 @@ TEST_PROGS := \ conntrack_tcp_unreplied.sh \ conntrack_vrf.sh \ ipvs.sh \ + ipvs_secure_tcp.sh \ nf_conntrack_packetdrill.sh \ nf_nat_edemux.sh \ nft_audit.sh \ @@ -50,6 +51,8 @@ TEST_GEN_FILES = \ connect_close \ conntrack_dump_flush \ conntrack_reverse_clash \ + gen_tcp_probe \ + ipvs_secure_tcp_mln \ nf_queue \ sctp_collision \ udpclash \ @@ -60,6 +63,9 @@ include ../../lib.mk $(OUTPUT)/nf_queue: CFLAGS += $(MNL_CFLAGS) $(OUTPUT)/nf_queue: LDLIBS += $(MNL_LDLIBS) +$(OUTPUT)/ipvs_secure_tcp_mln: CFLAGS += $(MNL_CFLAGS) +$(OUTPUT)/ipvs_secure_tcp_mln: LDLIBS += $(MNL_LDLIBS) + $(OUTPUT)/conntrack_dump_flush: CFLAGS += $(MNL_CFLAGS) $(OUTPUT)/conntrack_dump_flush: LDLIBS += $(MNL_LDLIBS) $(OUTPUT)/udpclash: LDLIBS += -lpthread diff --git a/tools/testing/selftests/net/netfilter/gen_tcp_probe.c b/tools/testing/selftests/net/netfilter/gen_tcp_probe.c new file mode 100644 index 0000000000000..d62bfdce70c06 --- /dev/null +++ b/tools/testing/selftests/net/netfilter/gen_tcp_probe.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Send a TCP SYN then a TCP ACK (no SYN-ACK, no data) to the VIP. + * IPVS's TCP state machine only inspects SYN/FIN/ACK/RST bits, so this + * exercises the INPUT-direction state transition: + * + * SYN: NONE -> SYN_RECV + * ACK: SYN_RECV -> ESTABLISHED (tcp_states, normal) + * SYN_RECV -> SYN_RECV (tcp_states_dos, secure_tcp) + * + * Requires CAP_NET_RAW. + / + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <stdint.h> +#include <arpa/inet.h> +#include <sys/socket.h> +#include <netinet/ip.h> +#include <netinet/tcp.h> +#include <linux/if_ether.h> + +static inline uint16_t csump(const void data, size_t len) +{ + const uint16_t p = data; + uint32_t sum = 0; + + while (len > 1) { + sum += p++; + len -= 2; + } + if (len) + sum += (const uint8_t )p; + while (sum >> 16) + sum = (sum & 0xffff) + (sum >> 16); + return ~sum; +} + +static void send_seg(int fd, const struct in_addr sip, uint16_t sport, + const struct in_addr dip, uint16_t dport, + uint32_t seq, int syn, int ack) +{ + uint8_t pkt[sizeof(struct iphdr) + sizeof(struct tcphdr)] = { 0 }; + struct iphdr ip = (struct iphdr )pkt; + struct tcphdr tcp = (struct tcphdr )(pkt + sizeof(struct iphdr)); + struct sockaddr_in dst; + + ip->version = 4; + ip->ihl = 5; + ip->tot_len = htons(sizeof(pkt)); + ip->id = htons((uint16_t)(seq & 0xffff)); + ip->ttl = 64; + ip->protocol = IPPROTO_TCP; + ip->saddr = sip->s_addr; + ip->daddr = dip->s_addr; + + tcp->source = sport; + tcp->dest = dport; + tcp->seq = htonl(seq); + tcp->ack_seq = htonl(seq + 1); + tcp->doff = 5; + if (syn) + tcp->syn = 1; + if (ack) + tcp->ack = 1; + tcp->window = htons(1024); + + ip->check = csump(ip, sizeof(struct iphdr)); + /* pseudo header for TCP checksum / + { + uint8_t ph[12]; + + memcpy(ph, &ip->saddr, 4); + memcpy(ph + 4, &ip->daddr, 4); + ph[8] = 0; + ph[9] = IPPROTO_TCP; + ph[10] = (sizeof(struct tcphdr) >> 8) & 0xff; + ph[11] = sizeof(struct tcphdr) & 0xff; + + uint8_t tcpbuf[12 + sizeof(struct tcphdr)]; + + memcpy(tcpbuf, ph, 12); + memcpy(tcpbuf + 12, tcp, sizeof(struct tcphdr)); + tcp->check = csump(tcpbuf, sizeof(tcpbuf)); + } + + memset(&dst, 0, sizeof(dst)); + dst.sin_family = AF_INET; + dst.sin_addr = dip; + dst.sin_port = dport; + sendto(fd, pkt, sizeof(pkt), 0, (struct sockaddr )&dst, + sizeof(dst)); +} + +int main(int argc, char argv[]) +{ + struct in_addr sip, dip; + uint16_t sport, dport; + int fd, one = 1; + uint32_t seq = 0x12345678; + + if (argc != 5) { + fprintf(stderr, "usage: %s <src_ip> <src_port> <dst_ip> <dst_port>\n", + argv[0]); + return 2; + } + inet_pton(AF_INET, argv[1], &sip); + sport = htons((uint16_t)atoi(argv[2])); + inet_pton(AF_INET, argv[3], &dip); + dport = htons((uint16_t)atoi(argv[4])); + + fd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW); + if (fd < 0) { + perror("raw socket"); + return 1; + } + setsockopt(fd, IPPROTO_IP, IP_HDRINCL, &one, sizeof(one)); + + send_seg(fd, &sip, sport, &dip, dport, seq, 1, 0); + usleep(100000); + send_seg(fd, &sip, sport, &dip, dport, seq + 1, 0, 1); + + close(fd); + return 0; +} diff --git a/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh new file mode 100755 index 0000000000000..b079c0fe6b798 --- /dev/null +++ b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp.sh @@ -0,0 +1,158 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Runtime test for per-service secure_tcp (IP_VS_SVC_F_SECURE_TCP). +# +# Sets up the same 3-namespace topology as ipvs.sh +# but checks the TCP state machine, not data forwarding. Two +# identical TCP services are added on the same VIP on different ports, +# one is marked secure_tcp, the other is not. For each a bare SYN is +# followed by a bare ACK (no SYN-ACK / no data). IPVS classifies the +# connection from the flag bits: +# * normal service: SYN -> SYN_RECV, ACK -> ESTABLISHED +# * secure_tcp service: SYN -> SYN_RECV, ACK -> SYN_RECV +# This test checks that this is the case via `ipvsadm -Lnc`. +# +# Requires root, netns, ipvsadm, nft, and the built helpers +# ipvs_secure_tcp_mln and gen_tcp_probe. + +source lib.sh + +ret=0 +readonly vip="207.175.44.110" +readonly gip="10.0.0.1" +readonly dip="172.16.0.1" +readonly rip="172.16.0.2" +readonly cip="10.0.0.2" +readonly sip="10.0.0.3" +readonly port_secure=8081 +readonly port_plain=8080 + +GREEN='\033[0;92m' +RED='\033[0;31m' +NC='\033[0m' + +checktool "ipvsadm -v" "run test without ipvsadm" +checktool "nft --version" "run test without nft" + +setup() { + setup_ns ns0 ns1 ns2 + + ip link add veth01 netns "${ns0}" type veth peer name veth10 netns "${ns1}" + ip link add veth02 netns "${ns0}" type veth peer name veth20 netns "${ns2}" + ip link add veth12 netns "${ns1}" type veth peer name veth21 netns "${ns2}" + + ip netns exec "${ns0}" ip link set veth01 up + ip netns exec "${ns0}" ip link set veth02 up + ip netns exec "${ns0}" ip link add br0 type bridge + ip netns exec "${ns0}" ip link set veth01 master br0 + ip netns exec "${ns0}" ip link set veth02 master br0 + ip netns exec "${ns0}" ip link set br0 up + ip netns exec "${ns0}" ip addr add "${cip}/24" dev br0 + + ip netns exec "${ns1}" ip link set veth10 up + ip netns exec "${ns1}" ip addr add "${gip}/24" dev veth10 + ip netns exec "${ns1}" ip link set veth12 up + ip netns exec "${ns1}" ip addr add "${dip}/24" dev veth12 + ip netns exec "${ns1}" ip link set lo up + ip netns exec "${ns1}" ip addr add "${vip}/32" dev lo:1 + ip netns exec "${ns1}" sysctl -qw net.ipv4.ip_forward=1 + + ip netns exec "${ns2}" ip link set veth20 up + ip netns exec "${ns2}" ip addr add "${sip}/24" dev veth20 + ip netns exec "${ns2}" ip link set veth21 up + ip netns exec "${ns2}" ip addr add "${rip}/24" dev veth21 + + ip netns exec "${ns2}" ip addr add "${vip}/32" dev lo:1 + + ip netns exec "${ns0}" ip route add "${vip}/32" via "${gip}" dev br0 + + # load ipvs, then the rr scheduler (separate calls: modprobe treats + # the second name as a module parameter, not a second module) + ip netns exec "${ns1}" modprobe ip_vs + ip netns exec "${ns1}" modprobe ip_vs_rr + + sleep 1 +} + +cleanup() { + cleanup_all_ns +} + +# State of the connection to the VIP:port, from `ipvsadm -Lnc`. +# Fields: pro expire state source virtual destination +conn_state() { + local vport=$1 + ip netns exec "${ns1}" ipvsadm -Lnc 2>/dev/null \| + awk -v vt="${vip}:${vport}" '$5==vt { print $3; exit }' +} + +assert_state() { + local port=$1 want=$2 + local got + got="$(conn_state "$port")" + echo " vip ${vip}:${port}: state=${got:-?}" + if [ "${got:-}" != "$want" ]; then + echo -e "${RED}FAIL${NC}: vip ${vip}:${port} expected state" \ + "${want}, got ${got:-none}" + ret=1 + fi +} + +test_secure() { + local bin probe + + # Register the two services (secure_tcp on the secure port) + bin="$(pwd)/ipvs_secure_tcp_mln" + probe="$(pwd)/gen_tcp_probe" + ip netns exec "${ns1}" "$bin" add "${vip}" "${port_secure}" secure + ip netns exec "${ns1}" "$bin" add "${vip}" "${port_plain}" plain + + # Add a real server to both services. Use NAT (-m): in DR the conn gets + # IP_VS_CONN_F_NOOUTPUT, which makes the client ACK an INPUT_ONLY event + # and even tcp_states_dos promotes to ESTABLISHED, hiding the difference. + ip netns exec "${ns1}" ipvsadm -a -m -t "${vip}:${port_secure}" -r "${rip}:${port_secure}" + ip netns exec "${ns1}" ipvsadm -a -m -t "${vip}:${port_plain}" -r "${rip}:${port_plain}" + + # verify the flag was actually set + local got + got="$(ip netns exec "${ns1}" "$bin" get "${vip}" "${port_secure}")" + echo " secured service reports: ${got}" + echo "${got}" \| grep -q "secure_tcp=1" \|\| + { echo -e "${RED}FAIL${NC}: flag not set"; ret=1; } + got="$(ip netns exec "${ns1}" "$bin" get "${vip}" "${port_plain}")" + echo "${got}" \| grep -q "secure_tcp=0" \|\| + { echo -e "${RED}FAIL${NC}: flag unexpectedly set"; ret=1; } + + # Drop any SYN on the real server so it stays silent (no RST that + # would interfere with the state-machine observation). + ip netns exec "${ns2}" nft add table inet filter + ip netns exec "${ns2}" nft add chain inet filter probe \ + '{ type filter hook input priority 0; }' + ip netns exec "${ns2}" nft add rule inet filter probe \ + tcp dport '{ '"${port_secure}"', '"${port_plain}"' }' drop + + # Push SYN then ACK to each service from the client + ip netns exec "${ns0}" "$probe" "${cip}" 40000 "${vip}" "${port_secure}" + ip netns exec "${ns0}" "$probe" "${cip}" 40001 "${vip}" "${port_plain}" + sleep 1 + + echo "Testing per-service secure_tcp..." + echo " --- connection table (ipvsadm -Lnc) ---" + ip netns exec "${ns1}" ipvsadm -Lnc 2>/dev/null + echo " --- end connection table ---" + assert_state "${port_plain}" ESTABLISHED + assert_state "${port_secure}" SYN_RECV +} + +trap cleanup EXIT + +setup +test_secure + +if [ "$ret" -ne 0 ]; then + echo -e "$(basename $0): ${RED}FAIL${NC}" + exit 1 +fi +echo -e "$(basename $0): ${GREEN}PASS${NC}" +exit 0 diff --git a/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c new file mode 100644 index 0000000000000..c15a3c28e6fec --- /dev/null +++ b/tools/testing/selftests/net/netfilter/ipvs_secure_tcp_mln.c @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * libmnl helper to set/query the per-service secure_tcp flag + * (IP_VS_SVC_F_SECURE_TCP), which ipvsadm does not expose. + * + * Usage: + * ipvs_secure_tcp_mln add <vip> <port> <secure\|plain> + * Create a TCP virtual service (scheduler "rr") with the flag either + * set or not. Add real servers afterwards with: + * ipvsadm -a -t <vip>:<port> -r <rs>:<port> + * ipvs_secure_tcp_mln get <vip> <port> + * Print "secure_tcp=<0\|1>" for the service. + / + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <arpa/inet.h> + +#include <linux/netlink.h> +#include <linux/genetlink.h> +#include <linux/ip_vs.h> + +#include <libmnl/libmnl.h> + +/ Fallback in case the kernel's installed uapi header is older / +#ifndef IP_VS_SVC_F_SECURE_TCP +#define IP_VS_SVC_F_SECURE_TCP 0x0040 +#endif + +/ 16-byte address storage, matching union nf_inet_addr for AF_INET / +struct inet_addr16 { + uint8_t all[16]; +}; + +/ ---------------- family resolver ---------------- / +static int ctrl_attr_cb(const struct nlattr attr, void data) +{ + const struct nlattr tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, CTRL_ATTR_MAX) < 0) + return MNL_CB_ERROR; + if (type == CTRL_ATTR_FAMILY_ID) { + if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0) + return MNL_CB_ERROR; + tb[CTRL_ATTR_FAMILY_ID] = attr; + } + return MNL_CB_OK; +} + +static int ctrl_data_cb(const struct nlmsghdr nlh, void data) +{ + const struct nlattr tb[CTRL_ATTR_MAX + 1] = { 0 }; + uint16_t fam = data; + + if (nlh->nlmsg_type != GENL_ID_CTRL) + return MNL_CB_OK; + mnl_attr_parse(nlh, sizeof(struct genlmsghdr), + (mnl_attr_cb_t)ctrl_attr_cb, tb); + if (tb[CTRL_ATTR_FAMILY_ID]) { + fam = mnl_attr_get_u16(tb[CTRL_ATTR_FAMILY_ID]); + return MNL_CB_STOP; + } + return MNL_CB_OK; +} + +static int resolve_family(const char name, uint16_t fam) +{ + struct mnl_socket nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr nlh; + struct genlmsghdr genl; + int ret; + + nl = mnl_socket_open(NETLINK_GENERIC); + if (!nl) + return -errno; + mnl_socket_bind(nl, 0, 0); + + nlh = mnl_nlmsg_put_header(buf); + genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); + genl->cmd = CTRL_CMD_GETFAMILY; + genl->version = 1; + nlh->nlmsg_type = GENL_ID_CTRL; + nlh->nlmsg_flags = NLM_F_REQUEST; + mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, name); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + mnl_socket_close(nl); + return -errno; + } + do { + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + if (ret < 0) { + if (errno == EAGAIN) + continue; + mnl_socket_close(nl); + return -errno; + } + ret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl), + (mnl_cb_t)ctrl_data_cb, fam); + } while (ret > 0 && fam == 0); + + mnl_socket_close(nl); + return fam ? 0 : -ENOENT; +} + +/ ---------------- fill service identifying attrs ---------------- / +static int fill_service(struct nlmsghdr nlh, const char vip, + uint16_t port, int full, int secure) +{ + struct inet_addr16 vaddr = { 0 }; + struct nlattr nest; + struct ip_vs_flags fl; + int af = AF_INET; + + if (inet_pton(af, vip, vaddr.all) != 1) { + fprintf(stderr, "bad VIP %s\n", vip); + return -EINVAL; + } + + nest = mnl_attr_nest_start(nlh, IPVS_CMD_ATTR_SERVICE); + mnl_attr_put_u16(nlh, IPVS_SVC_ATTR_AF, af); + mnl_attr_put_u16(nlh, IPVS_SVC_ATTR_PROTOCOL, IPPROTO_TCP); + mnl_attr_put(nlh, IPVS_SVC_ATTR_ADDR, sizeof(vaddr), &vaddr); + /* port/be16: port is passed in network order from main() / + mnl_attr_put_u16(nlh, IPVS_SVC_ATTR_PORT, port); + + if (full) { + mnl_attr_put_strz(nlh, IPVS_SVC_ATTR_SCHED_NAME, "rr"); + memset(&fl, 0, sizeof(fl)); + fl.mask = IP_VS_SVC_F_SECURE_TCP; + if (secure) + fl.flags = IP_VS_SVC_F_SECURE_TCP; + mnl_attr_put(nlh, IPVS_SVC_ATTR_FLAGS, sizeof(fl), &fl); + mnl_attr_put_u32(nlh, IPVS_SVC_ATTR_TIMEOUT, 0); + mnl_attr_put_u32(nlh, IPVS_SVC_ATTR_NETMASK, 0xffffffff); + } + mnl_attr_nest_end(nlh, nest); + return 0; +} + +static int send_cmd(struct mnl_socket nl, struct nlmsghdr nlh) +{ + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("sendto"); + return -1; + } + return 0; +} + +/ ---------------- get secure flag ---------------- / +static int svc_attr_cb(const struct nlattr attr, void data) +{ + const struct nlattr tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, IPVS_SVC_ATTR_MAX) < 0) + return MNL_CB_ERROR; + tb[type] = attr; + return MNL_CB_OK; +} + +static int get_cb(const struct nlmsghdr nlh, void data) +{ + const struct nlattr tb[IPVS_SVC_ATTR_MAX + 1] = { 0 }; + struct ip_vs_flags fl; + int secure = data; + struct nlattr nest; + + mnl_attr_for_each(nest, nlh, sizeof(struct genlmsghdr)) { + if (mnl_attr_get_type(nest) == IPVS_CMD_ATTR_SERVICE) + mnl_attr_parse_nested(nest, (mnl_attr_cb_t)svc_attr_cb, tb); + } + if (tb[IPVS_SVC_ATTR_FLAGS]) { + memcpy(&fl, mnl_attr_get_payload(tb[IPVS_SVC_ATTR_FLAGS]), + sizeof(fl)); + secure = !!(fl.flags & IP_VS_SVC_F_SECURE_TCP); + } + return MNL_CB_STOP; +} + +static int do_get(uint16_t fam, const char vip, uint16_t port) +{ + struct mnl_socket nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr nlh; + struct genlmsghdr genl; + int ret, secure = -1; + + nl = mnl_socket_open(NETLINK_GENERIC); + mnl_socket_bind(nl, 0, 0); + nlh = mnl_nlmsg_put_header(buf); + genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); + genl->cmd = IPVS_CMD_GET_SERVICE; + genl->version = IPVS_GENL_VERSION; + nlh->nlmsg_type = fam; + nlh->nlmsg_flags = NLM_F_REQUEST; + fill_service(nlh, vip, port, 0, 0); + send_cmd(nl, nlh); + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret >= 0) { + ret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl), + (mnl_cb_t)get_cb, &secure); + if (ret <= MNL_CB_STOP \|\| secure >= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + mnl_socket_close(nl); + if (secure < 0) + return -ENOENT; + printf("secure_tcp=%d\n", secure); + return 0; +} + +/ ---------------- add service with flag ---------------- / +static int do_add(uint16_t fam, const char vip, uint16_t port, int secure) +{ + struct mnl_socket nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr nlh; + struct genlmsghdr genl; + int ret; + + / NLM_F_EXCL: fail if the service already exists / + nlh = mnl_nlmsg_put_header(buf); + genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); + genl->cmd = IPVS_CMD_NEW_SERVICE; + genl->version = IPVS_GENL_VERSION; + nlh->nlmsg_type = fam; + nlh->nlmsg_flags = NLM_F_REQUEST \| NLM_F_ACK \| NLM_F_CREATE \| NLM_F_EXCL; + fill_service(nlh, vip, port, 1, secure); + + nl = mnl_socket_open(NETLINK_GENERIC); + mnl_socket_bind(nl, 0, 0); + if (send_cmd(nl, nlh) < 0) { + mnl_socket_close(nl); + return 1; + } + + / Read the reply so we can report why a command may have failed / + for (;;) { + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + if (ret <= 0) + break; + ret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl), + NULL, NULL); + if (ret < 0) { + int e = errno; + + fprintf(stderr, "IPVS netlink error: ret=%d errno=%d (%s)\n", + ret, e, strerror(e)); + mnl_socket_close(nl); + return 1; + } + if (ret <= MNL_CB_STOP) + break; + } + mnl_socket_close(nl); + return 0; +} + +int main(int argc, char argv[]) +{ + const char cmd, vip; + uint16_t fam; + uint16_t port; + int ret, secure = 0; + + if (argc < 4) { + fprintf(stderr, + "usage: %s add <vip> <port> <secure\|plain>\n" + " %s get <vip> <port>\n", argv[0], argv[0]); + return 2; + } + cmd = argv[1]; + vip = argv[2]; + port = (uint16_t)atoi(argv[3]); + port = htons(port); + + ret = resolve_family(IPVS_GENL_NAME, &fam); + if (ret) { + fprintf(stderr, "cannot resolve IPVS genl family: %s\n", + strerror(-ret)); + return 1; + } + + if (strcmp(cmd, "add") == 0) { + if (argc < 5) { + fprintf(stderr, "usage: %s add ... <secure\|plain>\n", + argv[0]); + return 2; + } + if (strcmp(argv[4], "secure") == 0) { + secure = 1; + } else if (strcmp(argv[4], "plain") != 0) { + fprintf(stderr, "unknown mode %s\n", argv[4]); + return 2; + } + return do_add(fam, vip, port, secure); + } else if (strcmp(cmd, "get") == 0) { + return do_get(fam, vip, port); + } + + fprintf(stderr, "unknown command %s\n", cmd); + return 2; +}
47/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 13154 output: 35 thoughts: 866 Thoughts: KMSAN Fuzzing Analysis: IPVS Secure TCP Patch Okay, let's break this down. My initial assessment is that this patch introduces new functionality around "secure TCP" handling within the IPVS (IP Virtual Server) subsystem, and I need to determine if it warrants a KMSAN fuzzing session. This requires careful consideration of where this new `IP_VS_CONN_F_SECURE_TCP` flag is used and how it might expose new memory access paths. First, the diffs themselves are straightforward. We have a new flag defined in `include/uapi/linux/ip_vs.h`, both for services (`IP_VS_SVC_F_SECURE_TCP`) and connections (`IP_VS_CONN_F_SECURE_TCP`). The service flag gets propagated to the connection flag in a few core IPVS functions within `ip_vs_core.c` like `ip_vs_sched_persist`, `ip_vs_schedule`, `ip_vs_leave`, and `ip_vs_new_conn_out`. This looks like a standard pattern: service-level configuration influencing connection behavior. We also see this connection flag being used in `ip_vs_ftp.c` for FTP connection helper creation. The most interesting part, and the one that raises the most immediate flags, is the change in `ip_vs_proto_tcp.c`. Specifically, the `set_tcp_state` function now conditionally uses a different TCP state table (`tcp_states_dos`) based on the `IP_VS_CONN_F_SECURE_TCP` flag. This is a clear path for control flow divergence based on the new flag. This is prime KMSAN territory. Different state tables imply different state transitions, different data structures, and the potential for new memory access patterns. The presence of selftests in `tools/testing/selftests/net/netfilter/...` is a good sign. It shows that someone has thought about how to exercise this functionality. These tests are useful, but self-tests have an inherent bias towards the intended functionality, and don't necessarily explore all possible code paths. However, how are these service flags set in the first place? I need to understand how `svc->flags` and thus `IP_VS_SVC_F_SECURE_TCP` get set. Is this via netlink, ioctl, or sockopt? I suspect netlink is involved, so I will need to check how the user-space sets this flag to determine whether any new input validation or data structures are relevant. I'll need to use `grepper` or similar tools to examine `ip_vs_ctl.c` or other relevant files. Based on the conditional change in `ip_vs_proto_tcp.c`, I'm leaning heavily towards `NeedsKMSAN = true`, but I need to confirm that user-space interactions are safe.
48/3	2026/09/12 02:37	tool	grepper	0m Args: { "Expression": "IP_VS_SVC_F_", "PathPrefix": "net/netfilter/ipvs" } Results: { "Output": "net/netfilter/ipvs/ip_vs_conn.c=1837=static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn cp)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1843-\tsvc = rcu_dereference(cp-\u003edest-\u003esvc);\nnet/netfilter/ipvs/ip_vs_conn.c:1844:\treturn svc \u0026\u0026 (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET);\nnet/netfilter/ipvs/ip_vs_conn.c-1845-}\n--\nnet/netfilter/ipvs/ip_vs_core.c=56=static inline unsigned int ip_vs_conn_secure_tcp_flags(struct ip_vs_service svc)\nnet/netfilter/ipvs/ip_vs_core.c-57-{\nnet/netfilter/ipvs/ip_vs_core.c:58:\treturn (svc-\u003eflags \u0026 IP_VS_SVC_F_SECURE_TCP) ?\nnet/netfilter/ipvs/ip_vs_core.c-59-\t\tIP_VS_CONN_F_SECURE_TCP : 0;\n--\nnet/netfilter/ipvs/ip_vs_core.c=437=ip_vs_sched_persist(struct ip_vs_service svc,\n--\nnet/netfilter/ipvs/ip_vs_core.c-575-\nnet/netfilter/ipvs/ip_vs_core.c:576:\tflags = (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET\nnet/netfilter/ipvs/ip_vs_core.c-577-\t\t \u0026\u0026 iph-\u003eprotocol == IPPROTO_UDP) ?\n--\nnet/netfilter/ipvs/ip_vs_core.c=628=ip_vs_schedule(struct ip_vs_service svc, struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_core.c-693-\t /\nnet/netfilter/ipvs/ip_vs_core.c:694:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_PERSISTENT)\nnet/netfilter/ipvs/ip_vs_core.c-695-\t\treturn ip_vs_sched_persist(svc, skb, cport, vport, ignored,\n--\nnet/netfilter/ipvs/ip_vs_core.c-723-\nnet/netfilter/ipvs/ip_vs_core.c:724:\tflags = (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET\nnet/netfilter/ipvs/ip_vs_core.c-725-\t\t \u0026\u0026 iph-\u003eprotocol == IPPROTO_UDP) ?\n--\nnet/netfilter/ipvs/ip_vs_core.c=773=int ip_vs_leave(struct ip_vs_service svc, struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_core.c-792-\t\tstruct ip_vs_conn cp;\nnet/netfilter/ipvs/ip_vs_core.c:793:\t\tunsigned int flags = ((svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET \u0026\u0026\nnet/netfilter/ipvs/ip_vs_core.c-794-\t\t\t\t iph-\u003eprotocol == IPPROTO_UDP) ?\n--\nnet/netfilter/ipvs/ip_vs_core.c=1321=struct ip_vs_conn ip_vs_new_conn_out(struct ip_vs_service svc,\n--\nnet/netfilter/ipvs/ip_vs_core.c-1346-\t/ for persistent service first create connection template /\nnet/netfilter/ipvs/ip_vs_core.c:1347:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_PERSISTENT) {\nnet/netfilter/ipvs/ip_vs_core.c-1348-\t\t/ apply netmask the same way ingress-side does /\n--\nnet/netfilter/ipvs/ip_vs_core.c-1378-\t/ connection flags /\nnet/netfilter/ipvs/ip_vs_core.c:1379:\tflags = ((svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET) \u0026\u0026\nnet/netfilter/ipvs/ip_vs_core.c-1380-\t\t iph-\u003eprotocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0;\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=382=static int ip_vs_svc_hash(struct ip_vs_service svc)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-388-\nnet/netfilter/ipvs/ip_vs_ctl.c:389:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_HASHED) {\nnet/netfilter/ipvs/ip_vs_ctl.c-390-\t\tpr_err(\"%s(): request for already hashed, called from %pS\\n\",\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-423-\tWRITE_ONCE(svc-\u003ehash_key, ip_vs_rht_build_hash_key(t, hash));\nnet/netfilter/ipvs/ip_vs_ctl.c:424:\tsvc-\u003eflags \|= IP_VS_SVC_F_HASHED;\nnet/netfilter/ipvs/ip_vs_ctl.c-425-\thlist_bl_add_head_rcu(\u0026svc-\u003es_list, head);\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=438=static int ip_vs_svc_unhash(struct ip_vs_service svc)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-445-\nnet/netfilter/ipvs/ip_vs_ctl.c:446:\tif (!(svc-\u003eflags \u0026 IP_VS_SVC_F_HASHED)) {\nnet/netfilter/ipvs/ip_vs_ctl.c-447-\t\tpr_err(\"%s(): request for unhash flagged, called from %pS\\n\",\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-481-\nnet/netfilter/ipvs/ip_vs_ctl.c:482:\tsvc-\u003eflags \u0026= ~IP_VS_SVC_F_HASHED;\nnet/netfilter/ipvs/ip_vs_ctl.c-483-\tatomic_dec(\u0026svc-\u003erefcnt);\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=1758=ip_vs_add_service(struct netns_ipvs ipvs, struct ip_vs_service_user_kern u,\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-1867-\tsvc-\u003efwmark = u-\u003efwmark;\nnet/netfilter/ipvs/ip_vs_ctl.c:1868:\tsvc-\u003eflags = u-\u003eflags \u0026 ~IP_VS_SVC_F_HASHED;\nnet/netfilter/ipvs/ip_vs_ctl.c-1869-\tsvc-\u003etimeout = u-\u003etimeout HZ;\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=1967=ip_vs_edit_service(struct ip_vs_service svc, struct ip_vs_service_user_kern u)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-2034-\t /\nnet/netfilter/ipvs/ip_vs_ctl.c:2035:\tsvc-\u003eflags = u-\u003eflags \| IP_VS_SVC_F_HASHED;\nnet/netfilter/ipvs/ip_vs_ctl.c-2036-\tsvc-\u003etimeout = u-\u003etimeout HZ;\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=3024=static int ip_vs_info_seq_show(struct seq_file seq, void v)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3057-\t\t\t\t\t sched_name,\nnet/netfilter/ipvs/ip_vs_ctl.c:3058:\t\t\t\t\t (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET)?\"ops \":\"\");\nnet/netfilter/ipvs/ip_vs_ctl.c-3059-\t\t} else {\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3061-\t\t\t\t svc-\u003efwmark, sched_name,\nnet/netfilter/ipvs/ip_vs_ctl.c:3062:\t\t\t\t (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET)?\"ops \":\"\");\nnet/netfilter/ipvs/ip_vs_ctl.c-3063-\t\t}\nnet/netfilter/ipvs/ip_vs_ctl.c-3064-\nnet/netfilter/ipvs/ip_vs_ctl.c:3065:\t\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_PERSISTENT)\nnet/netfilter/ipvs/ip_vs_ctl.c-3066-\t\t\tseq_printf(seq, \"persistent %d %08X\\n\",\n--\nnet/netfilter/ipvs/ip_vs_mh.c-33-\nnet/netfilter/ipvs/ip_vs_mh.c:34:#define IP_VS_SVC_F_SCHED_MH_FALLBACK\tIP_VS_SVC_F_SCHED1 /* MH fallback /\nnet/netfilter/ipvs/ip_vs_mh.c:35:#define IP_VS_SVC_F_SCHED_MH_PORT\tIP_VS_SVC_F_SCHED2 / MH use port /\nnet/netfilter/ipvs/ip_vs_mh.c-36-\n--\nnet/netfilter/ipvs/ip_vs_mh.c=471=ip_vs_mh_schedule(struct ip_vs_service svc, const struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_mh.c-482-\nnet/netfilter/ipvs/ip_vs_mh.c:483:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_SCHED_MH_PORT)\nnet/netfilter/ipvs/ip_vs_mh.c-484-\t\tport = ip_vs_mh_get_port(skb, iph);\n--\nnet/netfilter/ipvs/ip_vs_mh.c-487-\nnet/netfilter/ipvs/ip_vs_mh.c:488:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_SCHED_MH_FALLBACK)\nnet/netfilter/ipvs/ip_vs_mh.c-489-\t\tdest = ip_vs_mh_get_fallback(svc, s, hash_addr, port);\n--\nnet/netfilter/ipvs/ip_vs_sh.c=308=ip_vs_sh_schedule(struct ip_vs_service svc, const struct sk_buff *skb,\n--\nnet/netfilter/ipvs/ip_vs_sh.c-319-\nnet/netfilter/ipvs/ip_vs_sh.c:320:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_SCHED_SH_PORT)\nnet/netfilter/ipvs/ip_vs_sh.c-321-\t\tport = ip_vs_sh_get_port(skb, iph);\n--\nnet/netfilter/ipvs/ip_vs_sh.c-324-\nnet/netfilter/ipvs/ip_vs_sh.c:325:\tif (svc-\u003eflags \u0026 IP_VS_SVC_F_SCHED_SH_FALLBACK)\nnet/netfilter/ipvs/ip_vs_sh.c-326-\t\tdest = ip_vs_sh_get_fallback(svc, s, hash_addr, port);\n" }
49/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 17684 output: 39 thoughts: 59 Thoughts: Examining IPVS Connection Flags Okay, let's dive into how the `IP_VS_CONN_F_SECURE_TCP` flag, and connection flags in general, are managed within IPVS. My immediate focus is to pinpoint where these flags are actually used within the IPVS framework. I'm thinking specifically about the synchronization daemon, netlink interfaces, and whether they surface in proc or ioctl mechanisms. Understanding the propagation and interpretation of these flags is key to really grasping the connection lifecycle within the virtual server. I need to trace their flow through the system.
50/3	2026/09/12 02:37	tool	grepper	0m Args: { "Expression": "IP_VS_CONN_F_BACKUP_MASK", "PathPrefix": "net/netfilter/ipvs" } Results: { "Output": "net/netfilter/ipvs/ip_vs_sync.c=1066=static inline int ip_vs_proc_sync_conn(struct netns_ipvs ipvs, __u8 p, __u8 msg_end)\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1143-\t/ Get flags and Mask off unsupported */\nnet/netfilter/ipvs/ip_vs_sync.c:1144:\tflags = ntohl(s-\u003ev4.flags) \u0026 IP_VS_CONN_F_BACKUP_MASK;\nnet/netfilter/ipvs/ip_vs_sync.c-1145-\tflags \|= IP_VS_CONN_F_SYNC;\n" }
51/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 18094 output: 44 thoughts: 21 Thoughts: Here's my summary, as if I were thinking these thoughts: Diving into the `ip_vs_sync.c` Code Okay, time to get my hands dirty. I'm going to start by taking a look at `ip_vs_sync.c`. I have a hunch about a potential issue, and line 1144 sounds like a good starting point to explore it. Let's see what's happening around that section of the code and refresh my understanding. From there, I'll be better equipped to troubleshoot the area of concern.
52/3	2026/09/12 02:37	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_sync.c", "FirstLine": 1135, "LineCount": 40 } Results: { "Contents": "1135:\t\t\t\t\t\t ptype \u0026 ~IPVS_OPT_F_PARAM);\n1136:\t\t\t\t\tretc = 20;\n1137:\t\t\t\t\tgoto out;\n1138:\t\t\t\t}\n1139:\t\t\t}\n1140:\t\t\tp += plen; /* Next option /\n1141:\t\t}\n1142:\t\n1143:\t\t/ Get flags and Mask off unsupported /\n1144:\t\tflags = ntohl(s-\u003ev4.flags) \u0026 IP_VS_CONN_F_BACKUP_MASK;\n1145:\t\tflags \|= IP_VS_CONN_F_SYNC;\n1146:\t\tstate = ntohs(s-\u003ev4.state);\n1147:\t\n1148:\t\tif (!(flags \u0026 IP_VS_CONN_F_TEMPLATE)) {\n1149:\t\t\tpp = ip_vs_proto_get(s-\u003ev4.protocol);\n1150:\t\t\tif (!pp) {\n1151:\t\t\t\tIP_VS_DBG(3,\"BACKUP, Unsupported protocol %u\\n\",\n1152:\t\t\t\t\ts-\u003ev4.protocol);\n1153:\t\t\t\tretc = 30;\n1154:\t\t\t\tgoto out;\n1155:\t\t\t}\n1156:\t\t\tif (state \u003e= pp-\u003enum_states) {\n1157:\t\t\t\tIP_VS_DBG(3, \"BACKUP, Invalid %s state %u\\n\",\n1158:\t\t\t\t\tpp-\u003ename, state);\n1159:\t\t\t\tretc = 40;\n1160:\t\t\t\tgoto out;\n1161:\t\t\t}\n1162:\t\t} else {\n1163:\t\t\tif (state \u003e= IP_VS_CTPL_S_LAST)\n1164:\t\t\t\tIP_VS_DBG(7, \"BACKUP, Invalid tpl state %u\\n\",\n1165:\t\t\t\t\t state);\n1166:\t\t}\n1167:\t\tif (ip_vs_conn_fill_param_sync(ipvs, af, s, \u0026param, pe_data,\n1168:\t\t\t\t\t pe_data_len, pe_name, pe_name_len)) {\n1169:\t\t\tretc = 50;\n1170:\t\t\tgoto out;\n1171:\t\t}\n1172:\t\t/ If only IPv4, just silent skip IPv6 */\n1173:\t\tif (af == AF_INET)\n1174:\t\t\tip_vs_proc_conn(ipvs, \u0026param, flags, state, s-\u003ev4.protocol, af,\n" }
53/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 18939 output: 39 thoughts: 224 Thoughts: Analyzing the IPVS Connection Flag Update Okay, let's dive into this `IP_VS_CONN_F_BACKUP_MASK` update. It looks like we're changing the allowed initial bits for a backup server, specifically within the `include/uapi/linux/ip_vs.h` header file. The relevant code snippet shows the expansion of the macro: ```c /* Initial bits allowed in backup server */ #define IP_VS_CONN_F_BACKUP_MASK (IP_VS_CONN_F_FWD_MASK \| \ IP_VS_CONN_F_INACTIVE \| \ IP_VS_CONN_F_SEQ_MASK \| \ IP_VS_CONN_F_NO_CPORT \| \ - IP_VS_CONN_F_TEMPLATE \ + IP_VS_CONN_F_TEMPLATE \| \ + IP_VS_CONN_F_SECURE_TCP \ ) ``` So, they're adding `IP_VS_CONN_F_SECURE_TCP` to the mask. That makes sense, allows the backup server to deal with secure TCP connections as intended. However, I want to clarify what the previous meaning of bit 0x0008 was before the update. It's crucial to understand the implications of this change on existing code, so I'll need to review the older definition. Let's scroll back in the file and check the context around lines 70-110 to refresh my memory on what was there before the addition.
54/3	2026/09/12 02:37	tool	read-file	0m Args: { "File": "include/uapi/linux/ip_vs.h", "FirstLine": 70, "LineCount": 50 } Results: { "Contents": " 70:\t#define IP_VS_SO_GET_MAX\tIP_VS_SO_GET_DAEMON\n 71:\t\n 72:\t\n 73:\t/\n 74:\t IPVS Connection Flags\n 75:\t * Only flags 0..15 are sent to backup server\n 76:\t /\n 77:\t#define IP_VS_CONN_F_FWD_MASK\t0x0007\t\t/ mask for the fwd methods /\n 78:\t#define IP_VS_CONN_F_MASQ\t0x0000\t\t/ masquerading/NAT /\n 79:\t#define IP_VS_CONN_F_LOCALNODE\t0x0001\t\t/ local node /\n 80:\t#define IP_VS_CONN_F_TUNNEL\t0x0002\t\t/ tunneling /\n 81:\t#define IP_VS_CONN_F_DROUTE\t0x0003\t\t/ direct routing /\n 82:\t#define IP_VS_CONN_F_BYPASS\t0x0004\t\t/ cache bypass /\n 83:\t#define IP_VS_CONN_F_SYNC\t0x0020\t\t/ entry created by sync /\n 84:\t#define IP_VS_CONN_F_HASHED\t0x0040\t\t/ hashed entry /\n 85:\t#define IP_VS_CONN_F_NOOUTPUT\t0x0080\t\t/ no output packets /\n 86:\t#define IP_VS_CONN_F_INACTIVE\t0x0100\t\t/ not established /\n 87:\t#define IP_VS_CONN_F_OUT_SEQ\t0x0200\t\t/ must do output seq adjust /\n 88:\t#define IP_VS_CONN_F_IN_SEQ\t0x0400\t\t/ must do input seq adjust /\n 89:\t#define IP_VS_CONN_F_SEQ_MASK\t0x0600\t\t/ in/out sequence mask /\n 90:\t#define IP_VS_CONN_F_NO_CPORT\t0x0800\t\t/ no client port set yet /\n 91:\t#define IP_VS_CONN_F_TEMPLATE\t0x1000\t\t/ template, not connection /\n 92:\t#define IP_VS_CONN_F_ONE_PACKET\t0x2000\t\t/ forward only one packet /\n 93:\t#define IP_VS_CONN_F_SECURE_TCP\t0x0008\t\t/ use the hardened TCP table /\n 94:\t\n 95:\t/ Initial bits allowed in backup server /\n 96:\t#define IP_VS_CONN_F_BACKUP_MASK (IP_VS_CONN_F_FWD_MASK \| \\\n 97:\t\t\t\t\t IP_VS_CONN_F_NOOUTPUT \| \\\n 98:\t\t\t\t\t IP_VS_CONN_F_INACTIVE \| \\\n 99:\t\t\t\t\t IP_VS_CONN_F_SEQ_MASK \| \\\n 100:\t\t\t\t\t IP_VS_CONN_F_NO_CPORT \| \\\n 101:\t\t\t\t\t IP_VS_CONN_F_TEMPLATE \| \\\n 102:\t\t\t\t\t IP_VS_CONN_F_SECURE_TCP \\\n 103:\t\t\t\t\t )\n 104:\t\n 105:\t/ Bits allowed to update in backup server /\n 106:\t#define IP_VS_CONN_F_BACKUP_UPD_MASK (IP_VS_CONN_F_INACTIVE \| \\\n 107:\t\t\t\t\t IP_VS_CONN_F_SEQ_MASK)\n 108:\t\n 109:\t/ Flags that are not sent to backup server start from bit 16 /\n 110:\t#define IP_VS_CONN_F_NFCT\t(1 \u003c\u003c 16)\t/ use netfilter conntrack /\n 111:\t\n 112:\t/ Connection flags from destination that can be changed by user space */\n 113:\t#define IP_VS_CONN_F_DEST_MASK (IP_VS_CONN_F_FWD_MASK \| \\\n 114:\t\t\t\t\tIP_VS_CONN_F_ONE_PACKET \| \\\n 115:\t\t\t\t\tIP_VS_CONN_F_NFCT \| \\\n 116:\t\t\t\t\t0)\n 117:\t\n 118:\t#define IP_VS_SCHEDNAME_MAXLEN\t16\n 119:\t#define IP_VS_PENAME_MAXLEN\t16\n" }
55/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 20688 output: 39 thoughts: 123 Thoughts: Analyzing the IPVS Flags Okay, so I'm looking at this new IPVS configuration and immediately I see a few things. Bit 0x0008, that was previously unused, is now being assigned. Interesting. Now, I already know that Bits 0x0001, 0x0002, and 0x0004 are all part of the `FWD_MASK`, represented by 0x0007, which makes perfect sense. I also see that 0x0010 is still unused, and 0x0020 is, as expected, the SYNC flag. But the one that jumps out at me is `IP_VS_SVC_F_SECURE_TCP`, that's set to 0x0040. Now, to be absolutely sure what's going on here, I need to double-check my understanding of the relevant flags and ensure everything aligns with the kernel documentation. Let's pull up lines 20-40 of `include/uapi/linux/ip_vs.h` right now.
56/3	2026/09/12 02:37	tool	read-file	0m Args: { "File": "include/uapi/linux/ip_vs.h", "FirstLine": 20, "LineCount": 25 } Results: { "Contents": " 20:\t /\n 21:\t#define IP_VS_SVC_F_PERSISTENT\t0x0001\t\t/ persistent port /\n 22:\t#define IP_VS_SVC_F_HASHED\t0x0002\t\t/ hashed entry /\n 23:\t#define IP_VS_SVC_F_ONEPACKET\t0x0004\t\t/ one-packet scheduling /\n 24:\t#define IP_VS_SVC_F_SCHED1\t0x0008\t\t/ scheduler flag 1 /\n 25:\t#define IP_VS_SVC_F_SCHED2\t0x0010\t\t/ scheduler flag 2 /\n 26:\t#define IP_VS_SVC_F_SCHED3\t0x0020\t\t/ scheduler flag 3 /\n 27:\t\n 28:\t#define IP_VS_SVC_F_SCHED_SH_FALLBACK\tIP_VS_SVC_F_SCHED1 / SH fallback /\n 29:\t#define IP_VS_SVC_F_SCHED_SH_PORT\tIP_VS_SVC_F_SCHED2 / SH use port /\n 30:\t#define IP_VS_SVC_F_SECURE_TCP\t0x0040\t\t/ use the hardened TCP table /\n 31:\t\n 32:\t/\n 33:\t * IPVS sync daemon states\n 34:\t /\n 35:\t#define IP_VS_STATE_NONE\t0x0000\t\t/ daemon is stopped /\n 36:\t#define IP_VS_STATE_MASTER\t0x0001\t\t/ started as master /\n 37:\t#define IP_VS_STATE_BACKUP\t0x0002\t\t/ started as backup /\n 38:\t\n 39:\t/\n 40:\t * IPVS socket options\n 41:\t /\n 42:\t#define IP_VS_BASE_CTL\t\t(64+1024+64)\t\t/ base /\n 43:\t\n 44:\t#define IP_VS_SO_SET_NONE\tIP_VS_BASE_CTL\t\t/ just peek */\n" }
57/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 21642 output: 35 thoughts: 75 Thoughts: Here's my summary, as though I'm thinking through this process: Diving into the User-Space Service Population Alright, let's get down to brass tacks on how services are populated from user space. I need to understand the control flow, so I'll start with `ip_vs_ctl.c`. My hunch is that the crucial parsing will happen there. Specifically, I'll bet `IPVS_SVC_ATTR_FLAGS` is parsed within `ip_vs_genl_parse_service`. Okay, looks promising. To confirm and get some context, I should quickly cross-reference that tag, `IPVS_SVC_ATTR_FLAGS`, within the `net/netfilter/ipvs` directory. That'll provide the essential definition and usage context to solidify my understanding.
58/3	2026/09/12 02:37	tool	grepper	0m Args: { "Expression": "IPVS_SVC_ATTR_FLAGS", "PathPrefix": "net/netfilter/ipvs" } Results: { "Output": "net/netfilter/ipvs/ip_vs_ctl.c=3993=static const struct nla_policy ip_vs_svc_policy[IPVS_SVC_ATTR_MAX + 1] = {\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-4003-\t\t\t\t\t .len = IP_VS_PENAME_MAXLEN },\nnet/netfilter/ipvs/ip_vs_ctl.c:4004:\t[IPVS_SVC_ATTR_FLAGS]\t\t= { .type = NLA_BINARY,\nnet/netfilter/ipvs/ip_vs_ctl.c-4005-\t\t\t\t\t .len = sizeof(struct ip_vs_flags) },\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=4098=static int ip_vs_genl_fill_service(struct sk_buff skb,\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-4129-\t (pe \u0026\u0026 nla_put_string(skb, IPVS_SVC_ATTR_PE_NAME, pe-\u003ename)) \|\|\nnet/netfilter/ipvs/ip_vs_ctl.c:4130:\t nla_put(skb, IPVS_SVC_ATTR_FLAGS, sizeof(flags), \u0026flags) \|\|\nnet/netfilter/ipvs/ip_vs_ctl.c-4131-\t nla_put_u32(skb, IPVS_SVC_ATTR_TIMEOUT, svc-\u003etimeout / HZ) \|\|\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=4217=static int ip_vs_genl_parse_service(struct netns_ipvs ipvs,\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-4270-\t\tnla_pe = attrs[IPVS_SVC_ATTR_PE_NAME];\nnet/netfilter/ipvs/ip_vs_ctl.c:4271:\t\tnla_flags = attrs[IPVS_SVC_ATTR_FLAGS];\nnet/netfilter/ipvs/ip_vs_ctl.c-4272-\t\tnla_timeout = attrs[IPVS_SVC_ATTR_TIMEOUT];\n" }
59/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 22479 output: 44 thoughts: 29 Thoughts: Okay, here's my take on those functions, as if I were thinking it: Digging into the IPVS Genl Code Right, let's dive into `ip_vs_genl_fill_service` and `ip_vs_genl_parse_service`. Given the naming, they're clearly core to the generic netlink interface for handling IP Virtual Server (IPVS) service configurations. So, `fill` is likely about packing information into a generic netlink message, preparing it for transmission – probably for requests to read service details, or to return information to the user after an operation. I'd expect it to handle things like service address, port, protocol, flags, maybe statistics, and anything else relevant to the service's state. On the flip side, `parse` must be about unpacking a generic netlink message. It's the decoder ring, interpreting the incoming data – likely the user's commands to create, modify, or delete a service. It's responsible for validating the input, extracting the relevant parameters (like the destination addresses, weights, scheduler etc.), and making sure everything makes sense before applying the changes to the IPVS data structures. I'd need to confirm if these functions are used independently, or in tandem in other functions. I'd need to consider where their functions are used in the broader context of the genl interaction in IPVS.
60/3	2026/09/12 02:37	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_ctl.c", "FirstLine": 4120, "LineCount": 25 } Results: { "Contents": "4120:\t\t\t nla_put(skb, IPVS_SVC_ATTR_ADDR, sizeof(svc-\u003eaddr), \u0026svc-\u003eaddr) \|\|\n4121:\t\t\t nla_put_be16(skb, IPVS_SVC_ATTR_PORT, svc-\u003eport))\n4122:\t\t\t\tgoto nla_put_failure;\n4123:\t\t}\n4124:\t\n4125:\t\tsched = rcu_dereference(svc-\u003escheduler);\n4126:\t\tsched_name = sched ? sched-\u003ename : \"none\";\n4127:\t\tpe = rcu_dereference(svc-\u003epe);\n4128:\t\tif (nla_put_string(skb, IPVS_SVC_ATTR_SCHED_NAME, sched_name) \|\|\n4129:\t\t (pe \u0026\u0026 nla_put_string(skb, IPVS_SVC_ATTR_PE_NAME, pe-\u003ename)) \|\|\n4130:\t\t nla_put(skb, IPVS_SVC_ATTR_FLAGS, sizeof(flags), \u0026flags) \|\|\n4131:\t\t nla_put_u32(skb, IPVS_SVC_ATTR_TIMEOUT, svc-\u003etimeout / HZ) \|\|\n4132:\t\t nla_put_be32(skb, IPVS_SVC_ATTR_NETMASK, svc-\u003enetmask))\n4133:\t\t\tgoto nla_put_failure;\n4134:\t\tip_vs_copy_stats(\u0026kstats, \u0026svc-\u003estats);\n4135:\t\tif (ip_vs_genl_fill_stats(skb, IPVS_SVC_ATTR_STATS, \u0026kstats))\n4136:\t\t\tgoto nla_put_failure;\n4137:\t\tif (ip_vs_genl_fill_stats64(skb, IPVS_SVC_ATTR_STATS64, \u0026kstats))\n4138:\t\t\tgoto nla_put_failure;\n4139:\t\n4140:\t\tnla_nest_end(skb, nl_service);\n4141:\t\n4142:\t\treturn 0;\n4143:\t\n4144:\tnla_put_failure:\n" }
61/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 23414 output: 44 thoughts: 34 Thoughts: Okay, let's dive into this. Here's how I'd approach that snippet, considering I'm trying to understand the `flags` population process: Diving into `ip_vs_ctl.c` to Understand Flag Population Alright, so the question is how the `flags` variable is populated, right? My initial thought is to go straight to the code. Specifically, I need to understand what's happening within those lines you mentioned: 4100 through 4120 of `ip_vs_ctl.c`. That's where the critical logic concerning `flags` resides, according to your suggestion. My focus will be on the assignment and manipulation of that variable within that code block. I'll be looking for conditional statements, function calls, and any other indicators that tell the story of how that `flags` value gets its meaning. Are we using a bitwise OR operation? Assigning a direct value? Calling another function to compute something and return a bitmask? The context around those lines will be critical too – what are we processing at that stage, and what is `flags` actually representing? I'll probably also glance at the surrounding lines to make sure I am fully aware of the context of the code. This is how I'll gain a solid understanding of how those flags are ultimately set.
62/3	2026/09/12 02:37	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_ctl.c", "FirstLine": 4100, "LineCount": 20 } Results: { "Contents": "4100:\t{\n4101:\t\tstruct ip_vs_scheduler sched;\n4102:\t\tstruct ip_vs_pe pe;\n4103:\t\tstruct nlattr nl_service;\n4104:\t\tstruct ip_vs_flags flags = { .flags = svc-\u003eflags,\n4105:\t\t\t\t\t .mask = ~0 };\n4106:\t\tstruct ip_vs_kstats kstats;\n4107:\t\tchar sched_name;\n4108:\t\n4109:\t\tnl_service = nla_nest_start_noflag(skb, IPVS_CMD_ATTR_SERVICE);\n4110:\t\tif (!nl_service)\n4111:\t\t\treturn -EMSGSIZE;\n4112:\t\n4113:\t\tif (nla_put_u16(skb, IPVS_SVC_ATTR_AF, svc-\u003eaf))\n4114:\t\t\tgoto nla_put_failure;\n4115:\t\tif (svc-\u003efwmark) {\n4116:\t\t\tif (nla_put_u32(skb, IPVS_SVC_ATTR_FWMARK, svc-\u003efwmark))\n4117:\t\t\t\tgoto nla_put_failure;\n4118:\t\t} else {\n4119:\t\t\tif (nla_put_u16(skb, IPVS_SVC_ATTR_PROTOCOL, svc-\u003eprotocol) \|\|\n" }
63/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 24145 output: 45 thoughts: 64 Thoughts: Analyzing TCP Protocol Handling in IPVS Okay, so I'm looking at how flags are handled within the IPVS system. I've got this `flags` variable, currently set to `{ .flags = svc->flags, .mask = ~0 }`. Seems straightforward enough: it's initialized with the service's existing flags and a mask that effectively allows all bits to be considered. Now, my next move is to dive into the TCP protocol-specific code. Let's examine `ip_vs_proto_tcp.c`, specifically focusing on lines around 450 to 520. That section should give me the real meat of how TCP connections are being managed, the interactions of this `flags` with packet processing, and any specific flag manipulations occurring within that context. I'm hoping to get a clearer picture of the TCP state tracking and how it relates to the overall IPVS flow. I'll be looking for nuances and potential areas of interest within those lines.
64/3	2026/09/12 02:37	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_proto_tcp.c", "FirstLine": 445, "LineCount": 70 } Results: { "Contents": " 445:\t/ack/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},\n 446:\t/rst/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},\n 447:\t};\n 448:\t\n 449:\tstatic void tcp_timeout_change(struct ip_vs_proto_data pd, int flags)\n 450:\t{\n 451:\t\tint on = (flags \u0026 1);\t\t/ secure_tcp /\n 452:\t\n 453:\t\t/\n 454:\t\t * This remains the netns-wide default / global floor (e.g. when\n 455:\t\t * memory pressure kicks in). Per-service hardening is now carried\n 456:\t\t * by IP_VS_CONN_F_SECURE_TCP on each connection (set_tcp_state).\n 457:\t\t /\n 458:\t\tpd-\u003etcp_state_table = (on ? tcp_states_dos : tcp_states);\n 459:\t}\n 460:\t\n 461:\tstatic inline int tcp_state_idx(struct tcphdr th)\n 462:\t{\n 463:\t\tif (th-\u003erst)\n 464:\t\t\treturn 3;\n 465:\t\tif (th-\u003esyn)\n 466:\t\t\treturn 0;\n 467:\t\tif (th-\u003efin)\n 468:\t\t\treturn 1;\n 469:\t\tif (th-\u003eack)\n 470:\t\t\treturn 2;\n 471:\t\treturn -1;\n 472:\t}\n 473:\t\n 474:\tstatic inline void\n 475:\tset_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp,\n 476:\t\t int direction, struct tcphdr th)\n 477:\t{\n 478:\t\tint state_idx;\n 479:\t\tint new_state = IP_VS_TCP_S_CLOSE;\n 480:\t\tint state_off = tcp_state_off[direction];\n 481:\t\tconst struct tcp_states_t table;\n 482:\t\n 483:\t\t/\n 484:\t\t Update state offset to INPUT_ONLY if necessary\n 485:\t\t * or delete NO_OUTPUT flag if output packet detected\n 486:\t\t /\n 487:\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_NOOUTPUT) {\n 488:\t\t\tif (state_off == TCP_DIR_OUTPUT)\n 489:\t\t\t\tcp-\u003eflags \u0026= ~IP_VS_CONN_F_NOOUTPUT;\n 490:\t\t\telse\n 491:\t\t\t\tstate_off = TCP_DIR_INPUT_ONLY;\n 492:\t\t}\n 493:\t\n 494:\t\tif ((state_idx = tcp_state_idx(th)) \u003c 0) {\n 495:\t\t\tIP_VS_DBG(8, \"tcp_state_idx=%d!!!\\n\", state_idx);\n 496:\t\t\tgoto tcp_state_out;\n 497:\t\t}\n 498:\t\n 499:\t\ttable = pd-\u003etcp_state_table;\n 500:\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_SECURE_TCP)\n 501:\t\t\ttable = tcp_states_dos;\n 502:\t\tnew_state = table[state_off + state_idx].next_state[cp-\u003estate];\n 503:\t\n 504:\t tcp_state_out:\n 505:\t\tif (new_state != cp-\u003estate) {\n 506:\t\t\tstruct ip_vs_dest dest = cp-\u003edest;\n 507:\t\n 508:\t\t\tIP_VS_DBG_BUF(8, \"%s %s [%c%c%c%c] c:%s:%d v:%s:%d \"\n 509:\t\t\t\t \"d:%s:%d state: %s-\u003e%s conn-\u003erefcnt:%d\\n\",\n 510:\t\t\t\t pd-\u003epp-\u003ename,\n 511:\t\t\t\t ((state_off == TCP_DIR_OUTPUT) ?\n 512:\t\t\t\t \"output \" : \"input \"),\n 513:\t\t\t\t th-\u003esyn ? 'S' : '.',\n 514:\t\t\t\t th-\u003efin ? 'F' : '.',\n" }
65/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 25632 output: 36 thoughts: 65 Thoughts: Investigating Secure TCP Connection Flag Interactions Okay, so I'm digging deeper into how the `IP_VS_CONN_F_SECURE_TCP` flag interacts within the system. I need to understand its full reach. My first thought is to trace where else that specific `flags` member within the `ip_vs_conn` structure is being accessed. That's my starting point for a broader picture. Beyond that direct access, I'm thinking about potential methods for observation. Could `netlink`, the `/proc` filesystem, or perhaps an `ioctl` call be used to dump or expose these connection flags? Finding where this data is made visible will provide critical context. I need to figure out the different interfaces, if any, that are used to see, or modify the states of this flag.
66/3	2026/09/12 02:37	tool	grepper	0m Args: { "Expression": "flags", "PathPrefix": "net/netfilter/ipvs/ip_vs_conn.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_conn.c=54=static struct kmem_cache ip_vs_conn_cachep __read_mostly;\n--\nnet/netfilter/ipvs/ip_vs_conn.c-74- new table\nnet/netfilter/ipvs/ip_vs_conn.c:75: * - cp-\u003elock protects conn fields like cp-\u003eflags, cp-\u003edest\nnet/netfilter/ipvs/ip_vs_conn.c-76- /\n--\nnet/netfilter/ipvs/ip_vs_conn.c=261=static inline int ip_vs_conn_hash(struct ip_vs_conn cp)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-270-\nnet/netfilter/ipvs/ip_vs_conn.c:271:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_ONE_PACKET)\nnet/netfilter/ipvs/ip_vs_conn.c-272-\t\treturn 0;\n--\nnet/netfilter/ipvs/ip_vs_conn.c-292-\nnet/netfilter/ipvs/ip_vs_conn.c:293:\tcp-\u003eflags \|= IP_VS_CONN_F_HASHED;\nnet/netfilter/ipvs/ip_vs_conn.c-294-\tWRITE_ONCE(cp-\u003ehn0.hash_key, hash_key);\n--\nnet/netfilter/ipvs/ip_vs_conn.c-306-\tif (atomic_read(\u0026ipvs-\u003econn_count) \u003e t-\u003eu_thresh \u0026\u0026\nnet/netfilter/ipvs/ip_vs_conn.c:307:\t !test_and_set_bit(IP_VS_WORK_CONN_RESIZE, \u0026ipvs-\u003ework_flags))\nnet/netfilter/ipvs/ip_vs_conn.c-308-\t\tmod_delayed_work(system_dfl_long_wq, \u0026ipvs-\u003econn_resize_work, 0);\n--\nnet/netfilter/ipvs/ip_vs_conn.c=316=static inline bool ip_vs_conn_unlink(struct ip_vs_conn cp)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-324-\nnet/netfilter/ipvs/ip_vs_conn.c:325:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_ONE_PACKET)\nnet/netfilter/ipvs/ip_vs_conn.c-326-\t\treturn refcount_dec_if_one(\u0026cp-\u003erefcnt);\n--\nnet/netfilter/ipvs/ip_vs_conn.c-338-\nnet/netfilter/ipvs/ip_vs_conn.c:339:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_HASHED) {\nnet/netfilter/ipvs/ip_vs_conn.c-340-\t\t/ Decrease refcnt and unlink conn only if we are last user /\n--\nnet/netfilter/ipvs/ip_vs_conn.c-345-\t\t\t\thlist_bl_del_rcu(\u0026cp-\u003ehn1.node);\nnet/netfilter/ipvs/ip_vs_conn.c:346:\t\t\tcp-\u003eflags \u0026= ~IP_VS_CONN_F_HASHED;\nnet/netfilter/ipvs/ip_vs_conn.c-347-\t\t\tret = true;\n--\nnet/netfilter/ipvs/ip_vs_conn.c=367=__ip_vs_conn_in_get(const struct ip_vs_conn_param p)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-395-\t\t\t\t (!p-\u003ecport ^\nnet/netfilter/ipvs/ip_vs_conn.c:396:\t\t\t\t (!(cp-\u003eflags \u0026 IP_VS_CONN_F_NO_CPORT))) \u0026\u0026\nnet/netfilter/ipvs/ip_vs_conn.c-397-\t\t\t\t p-\u003eprotocol == cp-\u003eprotocol) {\n--\nnet/netfilter/ipvs/ip_vs_conn.c=475=struct ip_vs_conn ip_vs_ct_in_get(const struct ip_vs_conn_param p)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-514-\t\t\t\t p-\u003ecport == cp-\u003ecport \u0026\u0026\nnet/netfilter/ipvs/ip_vs_conn.c:515:\t\t\t\t cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE \u0026\u0026\nnet/netfilter/ipvs/ip_vs_conn.c-516-\t\t\t\t p-\u003eprotocol == cp-\u003eprotocol \u0026\u0026\n--\nnet/netfilter/ipvs/ip_vs_conn.c=620=static void __ip_vs_conn_put_timer(struct ip_vs_conn cp)\nnet/netfilter/ipvs/ip_vs_conn.c-621-{\nnet/netfilter/ipvs/ip_vs_conn.c:622:\tunsigned long t = (cp-\u003eflags \u0026 IP_VS_CONN_F_ONE_PACKET) ?\nnet/netfilter/ipvs/ip_vs_conn.c-623-\t\t0 : cp-\u003etimeout;\n--\nnet/netfilter/ipvs/ip_vs_conn.c=629=void ip_vs_conn_put(struct ip_vs_conn cp)\nnet/netfilter/ipvs/ip_vs_conn.c-630-{\nnet/netfilter/ipvs/ip_vs_conn.c:631:\tif ((cp-\u003eflags \u0026 IP_VS_CONN_F_ONE_PACKET) \u0026\u0026\nnet/netfilter/ipvs/ip_vs_conn.c-632-\t (refcount_read(\u0026cp-\u003erefcnt) == 1) \u0026\u0026\n--\nnet/netfilter/ipvs/ip_vs_conn.c=643=void ip_vs_conn_fill_cport(struct ip_vs_conn cp, __be16 cport)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-684-\t\t\tspin_lock_bh(\u0026cp-\u003elock);\nnet/netfilter/ipvs/ip_vs_conn.c:685:\t\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_NO_CPORT \u0026\u0026 by_me)\nnet/netfilter/ipvs/ip_vs_conn.c-686-\t\t\t\tcp-\u003ecport = 0;\n--\nnet/netfilter/ipvs/ip_vs_conn.c-709-\nnet/netfilter/ipvs/ip_vs_conn.c:710:\t/ Protect the cp-\u003eflags modification /\nnet/netfilter/ipvs/ip_vs_conn.c-711-\tspin_lock_bh(\u0026cp-\u003elock);\n--\nnet/netfilter/ipvs/ip_vs_conn.c-757-\t/ Fill cport once, even if multiple packets try to do it /\nnet/netfilter/ipvs/ip_vs_conn.c:758:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_NO_CPORT \u0026\u0026 (!cp-\u003ecport \|\| by_me)) {\nnet/netfilter/ipvs/ip_vs_conn.c-759-\t\t/ If we race with resizing make sure cport is set for dir 1 /\n--\nnet/netfilter/ipvs/ip_vs_conn.c-765-\t\t\tatomic_dec(\u0026ipvs-\u003eno_cport_conns[af_id]);\nnet/netfilter/ipvs/ip_vs_conn.c:766:\t\t\tcp-\u003eflags \u0026= ~IP_VS_CONN_F_NO_CPORT;\nnet/netfilter/ipvs/ip_vs_conn.c-767-\t\t}\n--\nnet/netfilter/ipvs/ip_vs_conn.c-774-\t\t\tWRITE_ONCE(cp-\u003ehn1.hash_key, hash_key_r);\nnet/netfilter/ipvs/ip_vs_conn.c:775:\t\t/ For dir=1 we do not check in flags if hn is already\nnet/netfilter/ipvs/ip_vs_conn.c-776-\t\t * rehashed but this check will do it.\n--\nnet/netfilter/ipvs/ip_vs_conn.c-796-/* Change forwarding method for hashed conn /\nnet/netfilter/ipvs/ip_vs_conn.c:797:static void ip_vs_conn_change_fwd_mask(struct ip_vs_conn cp, u32 new_flags)\nnet/netfilter/ipvs/ip_vs_conn.c-798-{\n--\nnet/netfilter/ipvs/ip_vs_conn.c-804-\t/* See ip_vs_conn_use_hash2() for reference /\nnet/netfilter/ipvs/ip_vs_conn.c:805:\tif ((cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE) \|\|\nnet/netfilter/ipvs/ip_vs_conn.c-806-\t / No change in double hashing ? /\nnet/netfilter/ipvs/ip_vs_conn.c-807-\t (IP_VS_FWD_METHOD(cp) == IP_VS_CONN_F_MASQ) ==\nnet/netfilter/ipvs/ip_vs_conn.c:808:\t ((new_flags \u0026 IP_VS_CONN_F_FWD_MASK) == IP_VS_CONN_F_MASQ)) {\nnet/netfilter/ipvs/ip_vs_conn.c:809:\t\tcp-\u003eflags = new_flags;\nnet/netfilter/ipvs/ip_vs_conn.c-810-\t\treturn;\n--\nnet/netfilter/ipvs/ip_vs_conn.c-825-\t\thlist_bl_del_rcu(\u0026cp-\u003ehn1.node);\nnet/netfilter/ipvs/ip_vs_conn.c:826:\t\tcp-\u003eflags = new_flags;\nnet/netfilter/ipvs/ip_vs_conn.c-827-\n--\nnet/netfilter/ipvs/ip_vs_conn.c-843-\t\tWRITE_ONCE(cp-\u003ehn1.hash_key, hash_key2);\nnet/netfilter/ipvs/ip_vs_conn.c:844:\t\tcp-\u003eflags = new_flags;\nnet/netfilter/ipvs/ip_vs_conn.c-845-\t\thlist_bl_add_head_rcu(\u0026cp-\u003ehn1.node, head2);\n--\nnet/netfilter/ipvs/ip_vs_conn.c=896=static void conn_resize_work_handler(struct work_struct work)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-914-\t/* Allow work to be queued again /\nnet/netfilter/ipvs/ip_vs_conn.c:915:\tclear_bit(IP_VS_WORK_CONN_RESIZE, \u0026ipvs-\u003ework_flags);\nnet/netfilter/ipvs/ip_vs_conn.c-916-\tt = rcu_dereference_protected(ipvs-\u003econn_tab, 1);\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1089=ip_vs_bind_dest(struct ip_vs_conn cp, struct ip_vs_dest dest)\nnet/netfilter/ipvs/ip_vs_conn.c-1090-{\nnet/netfilter/ipvs/ip_vs_conn.c:1091:\tunsigned int conn_flags;\nnet/netfilter/ipvs/ip_vs_conn.c:1092:\t__u32 flags;\nnet/netfilter/ipvs/ip_vs_conn.c-1093-\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1100-\nnet/netfilter/ipvs/ip_vs_conn.c:1101:\tconn_flags = atomic_read(\u0026dest-\u003econn_flags);\nnet/netfilter/ipvs/ip_vs_conn.c-1102-\tif (cp-\u003eprotocol != IPPROTO_UDP)\nnet/netfilter/ipvs/ip_vs_conn.c:1103:\t\tconn_flags \u0026= ~IP_VS_CONN_F_ONE_PACKET;\nnet/netfilter/ipvs/ip_vs_conn.c:1104:\tflags = cp-\u003eflags;\nnet/netfilter/ipvs/ip_vs_conn.c-1105-\t/ Bind with the destination and its corresponding transmitter /\nnet/netfilter/ipvs/ip_vs_conn.c:1106:\tif (flags \u0026 IP_VS_CONN_F_SYNC) {\nnet/netfilter/ipvs/ip_vs_conn.c-1107-\t\t/ Synced conns are hashed, so they can not get this flag /\nnet/netfilter/ipvs/ip_vs_conn.c:1108:\t\tconn_flags \u0026= ~IP_VS_CONN_F_ONE_PACKET;\nnet/netfilter/ipvs/ip_vs_conn.c-1109-\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1112-\t\t /\nnet/netfilter/ipvs/ip_vs_conn.c:1113:\t\tif (!(flags \u0026 IP_VS_CONN_F_TEMPLATE))\nnet/netfilter/ipvs/ip_vs_conn.c:1114:\t\t\tconn_flags \u0026= ~IP_VS_CONN_F_INACTIVE;\nnet/netfilter/ipvs/ip_vs_conn.c-1115-\t\t/* connections inherit forwarding method from dest /\nnet/netfilter/ipvs/ip_vs_conn.c:1116:\t\tflags \u0026= ~(IP_VS_CONN_F_FWD_MASK \| IP_VS_CONN_F_NOOUTPUT);\nnet/netfilter/ipvs/ip_vs_conn.c:1117:\t\tflags \|= conn_flags;\nnet/netfilter/ipvs/ip_vs_conn.c-1118-\t\t/ Changing forwarding method for hashed conn can\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1120-\t\t /\nnet/netfilter/ipvs/ip_vs_conn.c:1121:\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_HASHED)\nnet/netfilter/ipvs/ip_vs_conn.c:1122:\t\t\tip_vs_conn_change_fwd_mask(cp, flags);\nnet/netfilter/ipvs/ip_vs_conn.c-1123-\t\telse\nnet/netfilter/ipvs/ip_vs_conn.c:1124:\t\t\tcp-\u003eflags = flags;\nnet/netfilter/ipvs/ip_vs_conn.c-1125-\t} else {\nnet/netfilter/ipvs/ip_vs_conn.c:1126:\t\tflags \|= conn_flags;\nnet/netfilter/ipvs/ip_vs_conn.c:1127:\t\tcp-\u003eflags = flags;\nnet/netfilter/ipvs/ip_vs_conn.c-1128-\t}\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1131-\tIP_VS_DBG_BUF(7, \"Bind-dest %s c:%s:%d v:%s:%d \"\nnet/netfilter/ipvs/ip_vs_conn.c:1132:\t\t \"d:%s:%d fwd:%c s:%u conn-\u003eflags:%X conn-\u003erefcnt:%d \"\nnet/netfilter/ipvs/ip_vs_conn.c-1133-\t\t \"dest-\u003erefcnt:%d\\n\",\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1138-\t\t ip_vs_fwd_tag(cp), cp-\u003estate,\nnet/netfilter/ipvs/ip_vs_conn.c:1139:\t\t cp-\u003eflags, refcount_read(\u0026cp-\u003erefcnt),\nnet/netfilter/ipvs/ip_vs_conn.c-1140-\t\t refcount_read(\u0026dest-\u003erefcnt));\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1142-\t/ Update the connection counters /\nnet/netfilter/ipvs/ip_vs_conn.c:1143:\tif (!(flags \u0026 IP_VS_CONN_F_TEMPLATE)) {\nnet/netfilter/ipvs/ip_vs_conn.c-1144-\t\tint tc;\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1146-\t\t/ It is a normal connection, so modify the counters\nnet/netfilter/ipvs/ip_vs_conn.c:1147:\t\t * according to the flags, later the protocol can\nnet/netfilter/ipvs/ip_vs_conn.c-1148-\t\t * update them on state change\nnet/netfilter/ipvs/ip_vs_conn.c-1149-\t\t /\nnet/netfilter/ipvs/ip_vs_conn.c:1150:\t\tif (!(flags \u0026 IP_VS_CONN_F_INACTIVE))\nnet/netfilter/ipvs/ip_vs_conn.c-1151-\t\t\tatomic_inc(\u0026dest-\u003eactiveconns);\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1167=void ip_vs_try_bind_dest(struct ip_vs_conn cp)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1179-\t\t\t cp-\u003edport, \u0026cp-\u003evaddr, cp-\u003evport,\nnet/netfilter/ipvs/ip_vs_conn.c:1180:\t\t\t cp-\u003eprotocol, cp-\u003efwmark, cp-\u003eflags);\nnet/netfilter/ipvs/ip_vs_conn.c-1181-\tif (dest) {\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1220=static inline void ip_vs_unbind_dest(struct ip_vs_conn cp)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1227-\tIP_VS_DBG_BUF(7, \"Unbind-dest %s c:%s:%d v:%s:%d \"\nnet/netfilter/ipvs/ip_vs_conn.c:1228:\t\t \"d:%s:%d fwd:%c s:%u conn-\u003eflags:%X conn-\u003erefcnt:%d \"\nnet/netfilter/ipvs/ip_vs_conn.c-1229-\t\t \"dest-\u003erefcnt:%d\\n\",\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1234-\t\t ip_vs_fwd_tag(cp), cp-\u003estate,\nnet/netfilter/ipvs/ip_vs_conn.c:1235:\t\t cp-\u003eflags, refcount_read(\u0026cp-\u003erefcnt),\nnet/netfilter/ipvs/ip_vs_conn.c-1236-\t\t refcount_read(\u0026dest-\u003erefcnt));\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1238-\t/ Update the connection counters /\nnet/netfilter/ipvs/ip_vs_conn.c:1239:\tif (!(cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE)) {\nnet/netfilter/ipvs/ip_vs_conn.c-1240-\t\tint tc;\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1242-\t\t/ It is a normal connection, so decrease the counters /\nnet/netfilter/ipvs/ip_vs_conn.c:1243:\t\tif (!(cp-\u003eflags \u0026 IP_VS_CONN_F_INACTIVE))\nnet/netfilter/ipvs/ip_vs_conn.c-1244-\t\t\tatomic_dec(\u0026dest-\u003eactiveconns);\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1273=int ip_vs_check_template(struct ip_vs_conn ct, struct ip_vs_dest cdest)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1281-\tif ((dest == NULL) \|\|\nnet/netfilter/ipvs/ip_vs_conn.c:1282:\t !(dest-\u003ecflags \u0026 IP_VS_DEST_CF_AVAILABLE) \|\|\nnet/netfilter/ipvs/ip_vs_conn.c-1283-\t expire_quiescent_template(ipvs, dest) \|\|\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1347=static void ip_vs_conn_expire(struct timer_list t)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1371-\t\t\tif (has_ref \u0026\u0026 !atomic_read(\u0026ct-\u003en_control) \u0026\u0026\nnet/netfilter/ipvs/ip_vs_conn.c:1372:\t\t\t (!(ct-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE) \|\|\nnet/netfilter/ipvs/ip_vs_conn.c-1373-\t\t\t !(ct-\u003estate \u0026 IP_VS_CTPL_S_ASSURED))) {\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1380-\nnet/netfilter/ipvs/ip_vs_conn.c:1381:\t\tif ((cp-\u003eflags \u0026 IP_VS_CONN_F_NFCT) \u0026\u0026\nnet/netfilter/ipvs/ip_vs_conn.c:1382:\t\t !(cp-\u003eflags \u0026 IP_VS_CONN_F_ONE_PACKET)) {\nnet/netfilter/ipvs/ip_vs_conn.c-1383-\t\t\t/* Do not access conntracks during subsys cleanup\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1394-\t\tip_vs_unbind_dest(cp);\nnet/netfilter/ipvs/ip_vs_conn.c:1395:\t\tif (unlikely(cp-\u003eflags \u0026 IP_VS_CONN_F_NO_CPORT)) {\nnet/netfilter/ipvs/ip_vs_conn.c-1396-\t\t\tint af_id = ip_vs_af_index(cp-\u003eaf);\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1399-\t\t}\nnet/netfilter/ipvs/ip_vs_conn.c:1400:\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_ONE_PACKET)\nnet/netfilter/ipvs/ip_vs_conn.c-1401-\t\t\tip_vs_conn_rcu_free(\u0026cp-\u003ercu_head);\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1444=ip_vs_conn_new(const struct ip_vs_conn_param p, int dest_af,\nnet/netfilter/ipvs/ip_vs_conn.c:1445:\t const union nf_inet_addr daddr, __be16 dport, unsigned int flags,\nnet/netfilter/ipvs/ip_vs_conn.c-1446-\t struct ip_vs_dest dest, __u32 fwmark)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1484-\tcp-\u003edport = dport;\nnet/netfilter/ipvs/ip_vs_conn.c:1485:\tcp-\u003eflags\t = flags;\nnet/netfilter/ipvs/ip_vs_conn.c-1486-\tcp-\u003efwmark = fwmark;\nnet/netfilter/ipvs/ip_vs_conn.c:1487:\tif (flags \u0026 IP_VS_CONN_F_TEMPLATE \u0026\u0026 p-\u003epe) {\nnet/netfilter/ipvs/ip_vs_conn.c-1488-\t\tip_vs_pe_get(p-\u003epe);\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1516-\nnet/netfilter/ipvs/ip_vs_conn.c:1517:\tif (unlikely(flags \u0026 IP_VS_CONN_F_NO_CPORT)) {\nnet/netfilter/ipvs/ip_vs_conn.c-1518-\t\tint af_id = ip_vs_af_index(cp-\u003eaf);\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1551-\tif (ip_vs_conntrack_enabled(ipvs))\nnet/netfilter/ipvs/ip_vs_conn.c:1552:\t\tcp-\u003eflags \|= IP_VS_CONN_F_NFCT;\nnet/netfilter/ipvs/ip_vs_conn.c-1553-\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1734=static const struct seq_operations ip_vs_conn_seq_ops = {\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1740-\nnet/netfilter/ipvs/ip_vs_conn.c:1741:static const char ip_vs_origin_name(unsigned int flags)\nnet/netfilter/ipvs/ip_vs_conn.c-1742-{\nnet/netfilter/ipvs/ip_vs_conn.c:1743:\tif (flags \u0026 IP_VS_CONN_F_SYNC)\nnet/netfilter/ipvs/ip_vs_conn.c-1744-\t\treturn \"SYNC\";\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1749=static int ip_vs_conn_sync_seq_show(struct seq_file seq, void v)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1775-\t\t\t\tip_vs_state_name(cp),\nnet/netfilter/ipvs/ip_vs_conn.c:1776:\t\t\t\tip_vs_origin_name(cp-\u003eflags),\nnet/netfilter/ipvs/ip_vs_conn.c-1777-\t\t\t\tjiffies_delta_to_msecs(cp-\u003etimer.expires -\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1788-\t\t\t\tip_vs_state_name(cp),\nnet/netfilter/ipvs/ip_vs_conn.c:1789:\t\t\t\tip_vs_origin_name(cp-\u003eflags),\nnet/netfilter/ipvs/ip_vs_conn.c-1790-\t\t\t\tjiffies_delta_to_msecs(cp-\u003etimer.expires -\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1837=static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn cp)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1843-\tsvc = rcu_dereference(cp-\u003edest-\u003esvc);\nnet/netfilter/ipvs/ip_vs_conn.c:1844:\treturn svc \u0026\u0026 (svc-\u003eflags \u0026 IP_VS_SVC_F_ONEPACKET);\nnet/netfilter/ipvs/ip_vs_conn.c-1845-}\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1847=void ip_vs_random_dropentry(struct netns_ipvs ipvs)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1875-\t\t\t\tcontinue;\nnet/netfilter/ipvs/ip_vs_conn.c:1876:\t\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE) {\nnet/netfilter/ipvs/ip_vs_conn.c-1877-\t\t\t\t/* connection template of OPS /\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1998=void ip_vs_expire_nodest_conn_flush(struct netns_ipvs ipvs)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-2022-\t\t\tdest = cp-\u003edest;\nnet/netfilter/ipvs/ip_vs_conn.c:2023:\t\t\tif (!dest \|\| (dest-\u003ecflags \u0026 IP_VS_DEST_CF_AVAILABLE))\nnet/netfilter/ipvs/ip_vs_conn.c-2024-\t\t\t\tcontinue;\n" }
67/3	2026/09/12 02:37	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 32983 output: 44 thoughts: 100 Thoughts: My Initial Thoughts on IPVS Connection Allocation Okay, so I'm diving into the IPVS connection management, specifically the allocation process. Let's start with `ip_vs_conn_new`. Ah, here it is, the line that kicks off the allocation: `cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);`. Wait a second! I need to be absolutely sure about how this struct, `ip_vs_conn`, is being created. Best to double-check that `ip_vs_conn_new` function in `net/netfilter/ipvs/ip_vs_conn.c` to confirm my understanding of the allocation details.
68/3	2026/09/12 02:38	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_conn.c", "FirstLine": 1444, "LineCount": 45 } Results: { "Contents": "1444:\tip_vs_conn_new(const struct ip_vs_conn_param p, int dest_af,\n1445:\t\t const union nf_inet_addr daddr, __be16 dport, unsigned int flags,\n1446:\t\t struct ip_vs_dest dest, __u32 fwmark)\n1447:\t{\n1448:\t\tstruct ip_vs_conn cp;\n1449:\t\tstruct netns_ipvs ipvs = p-\u003eipvs;\n1450:\t\tstruct ip_vs_proto_data pd = ip_vs_proto_data_get(p-\u003eipvs,\n1451:\t\t\t\t\t\t\t\t p-\u003eprotocol);\n1452:\t\t/* Increment conn_count up to conn_max /\n1453:\t\tint count = atomic_read(\u0026ipvs-\u003econn_count);\n1454:\t\tint max = sysctl_conn_max(ipvs);\n1455:\t\n1456:\t\tdo {\n1457:\t\t\tif (count \u003e= max)\n1458:\t\t\t\treturn NULL;\n1459:\t\t} while (!atomic_try_cmpxchg(\u0026ipvs-\u003econn_count, \u0026count, count + 1));\n1460:\t\n1461:\t\tcp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);\n1462:\t\tif (cp == NULL) {\n1463:\t\t\tatomic_dec(\u0026ipvs-\u003econn_count);\n1464:\t\t\tIP_VS_ERR_RL(\"%s(): no memory\\n\", __func__);\n1465:\t\t\treturn NULL;\n1466:\t\t}\n1467:\t\n1468:\t\tINIT_HLIST_BL_NODE(\u0026cp-\u003ehn0.node);\n1469:\t\tINIT_HLIST_BL_NODE(\u0026cp-\u003ehn1.node);\n1470:\t\ttimer_setup(\u0026cp-\u003etimer, ip_vs_conn_expire, 0);\n1471:\t\tcp-\u003eipvs\t = ipvs;\n1472:\t\tcp-\u003ehn0.dir\t = 0;\n1473:\t\tcp-\u003eaf\t\t = p-\u003eaf;\n1474:\t\tcp-\u003ehn1.dir\t = 1;\n1475:\t\tcp-\u003edaf\t\t = dest_af;\n1476:\t\tcp-\u003eprotocol\t = p-\u003eprotocol;\n1477:\t\tip_vs_addr_set(p-\u003eaf, \u0026cp-\u003ecaddr, p-\u003ecaddr);\n1478:\t\tcp-\u003ecport\t = p-\u003ecport;\n1479:\t\t/ proto should only be IPPROTO_IP if p-\u003evaddr is a fwmark */\n1480:\t\tip_vs_addr_set(p-\u003eprotocol == IPPROTO_IP ? AF_UNSPEC : p-\u003eaf,\n1481:\t\t\t \u0026cp-\u003evaddr, p-\u003evaddr);\n1482:\t\tcp-\u003evport\t = p-\u003evport;\n1483:\t\tip_vs_addr_set(cp-\u003edaf, \u0026cp-\u003edaddr, daddr);\n1484:\t\tcp-\u003edport = dport;\n1485:\t\tcp-\u003eflags\t = flags;\n1486:\t\tcp-\u003efwmark = fwmark;\n1487:\t\tif (flags \u0026 IP_VS_CONN_F_TEMPLATE \u0026\u0026 p-\u003epe) {\n1488:\t\t\tip_vs_pe_get(p-\u003epe);\n" }
69/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 34164 output: 35 thoughts: 63 Thoughts: Here's my take on the thought process, as if it were my own: Investigating the Allocation Path Okay, so I'm looking at how connections are managed, and it seems `kmem_cache_alloc` is grabbing the connection struct, let's call it `cp`, from `ip_vs_conn_cachep`. That's the key. Where does this cache come from? I need to understand how `ip_vs_conn_cachep` is set up. My next move is clear: I need to trace its creation and initialization. I'll jump over to the `ip_vs_conn_init` function, or wherever the thing is actually defined. That should lead me to the necessary context.
70/3	2026/09/12 02:38	tool	grepper	0m Args: { "Expression": "ip_vs_conn_cachep", "PathPrefix": "net/netfilter/ipvs" } Results: { "Output": "net/netfilter/ipvs/ip_vs_conn.c=51=int ip_vs_conn_tab_size __read_mostly;\n--\nnet/netfilter/ipvs/ip_vs_conn.c-53-/* SLAB cache for IPVS connections /\nnet/netfilter/ipvs/ip_vs_conn.c:54:static struct kmem_cache ip_vs_conn_cachep __read_mostly;\nnet/netfilter/ipvs/ip_vs_conn.c-55-\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1312=static void ip_vs_conn_rcu_free(struct rcu_head head)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1318-\tkfree(cp-\u003epe_data);\nnet/netfilter/ipvs/ip_vs_conn.c:1319:\tkmem_cache_free(ip_vs_conn_cachep, cp);\nnet/netfilter/ipvs/ip_vs_conn.c-1320-}\n--\nnet/netfilter/ipvs/ip_vs_conn.c=1444=ip_vs_conn_new(const struct ip_vs_conn_param p, int dest_af,\n--\nnet/netfilter/ipvs/ip_vs_conn.c-1460-\nnet/netfilter/ipvs/ip_vs_conn.c:1461:\tcp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);\nnet/netfilter/ipvs/ip_vs_conn.c-1462-\tif (cp == NULL) {\n--\nnet/netfilter/ipvs/ip_vs_conn.c=2106=int __init ip_vs_conn_init(void)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-2128-\t/* Allocate ip_vs_conn slab cache /\nnet/netfilter/ipvs/ip_vs_conn.c:2129:\tip_vs_conn_cachep = KMEM_CACHE(ip_vs_conn, SLAB_HWCACHE_ALIGN);\nnet/netfilter/ipvs/ip_vs_conn.c:2130:\tif (!ip_vs_conn_cachep)\nnet/netfilter/ipvs/ip_vs_conn.c-2131-\t\treturn -ENOMEM;\n--\nnet/netfilter/ipvs/ip_vs_conn.c=2141=void ip_vs_conn_cleanup(void)\n--\nnet/netfilter/ipvs/ip_vs_conn.c-2145-\t/ Release the empty cache */\nnet/netfilter/ipvs/ip_vs_conn.c:2146:\tkmem_cache_destroy(ip_vs_conn_cachep);\nnet/netfilter/ipvs/ip_vs_conn.c-2147-}\n" }
71/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 35163 output: 32 thoughts: 154 Thoughts: Diving into the TCP State Machine in IPVS Okay, time to dig into `ip_vs_proto_tcp.c` and refresh my understanding of how IPVS handles TCP states. Specifically, I need to see how the connection states are managed. Looking at `set_tcp_state`, I see this section: ```c table = pd->tcp_state_table; if (cp->flags & IP_VS_CONN_F_SECURE_TCP) table = tcp_states_dos; new_state = table[state_off + state_idx].next_state[cp->state]; ``` Hmm, interesting. I understand `pd->tcp_state_table` points to a state table, likely the default one. But that `if` statement… `tcp_states_dos`? And the fact it's used when `IP_VS_CONN_F_SECURE_TCP` is set suggests it is a specific state table. My spidey-sense is tingling. I need to understand this better. What's so special about `tcp_states_dos`? What are the implications of using it over the default? Guess I'll be checking `tcp_states_dos` definition right now in the same file. I need to understand how the connection state transitions work under this "DOS" flag. I bet it has some implications on how connections are handled to mitigate against DoS attacks.
72/3	2026/09/12 02:38	tool	grepper	0m Args: { "Expression": "tcp_states_dos", "PathPrefix": "net/netfilter/ipvs" } Results: { "Output": "net/netfilter/ipvs/ip_vs_proto_tcp.c=403=static struct tcp_states_t tcp_states[] = {\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-425-\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:426:static struct tcp_states_t tcp_states_dos[] = {\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-427-/\tINPUT /\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c=449=static void tcp_timeout_change(struct ip_vs_proto_data pd, int flags)\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-457-\t /\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:458:\tpd-\u003etcp_state_table = (on ? tcp_states_dos : tcp_states);\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-459-}\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c=475=set_tcp_state(struct ip_vs_proto_data pd, struct ip_vs_conn cp,\n--\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-500-\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_SECURE_TCP)\nnet/netfilter/ipvs/ip_vs_proto_tcp.c:501:\t\ttable = tcp_states_dos;\nnet/netfilter/ipvs/ip_vs_proto_tcp.c-502-\tnew_state = table[state_off + state_idx].next_state[cp-\u003estate];\n" }
73/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 36115 output: 36 thoughts: 275 Thoughts: My Analysis of the `tcp_states_dos` Patch Okay, so I'm looking at this patch and immediately, the `tcp_states_dos` table in `ip_vs_proto_tcp.c` catches my eye. It's static, and seems structurally identical to `tcp_states`. Before this, the code would switch `pd->tcp_state_table` between the two based on `secure_tcp` sysctl or timeout changes. Now, it appears if `cp->flags` has the `IP_VS_CONN_F_SECURE_TCP` flag set, it's directly setting `table` to `tcp_states_dos`. Hmm, this feels like it's going to cause issues. I have to think about the user space interaction here. How does user space even manipulate the `IP_VS_SVC_F_SECURE_TCP` flag? Where's that set and retrieved? I need to dig into `ip_vs_ctl.c` to understand the flow. Specifically, I need to see how `svc->flags` is being set or returned to user space. I bet it goes through netlink, ioctl, or sockopt – that's usually how these things are exposed. I'm going to have to check `ip_vs_genl_fill_service` and `ip_vs_genl_parse_service`, and also the `do_ip_vs_get_ctl` and `do_ip_vs_set_ctl` functions. I need to know exactly how those flags are marshaled to and from user space, because if they're not synchronized correctly, this is going to be a disaster. I'm imagining a situation where the kernel sets `tcp_states_dos` internally, but user space thinks it's operating on `tcp_states`. This whole change depends on that user-space interaction being right. Gotta get the full picture here.
74/3	2026/09/12 02:38	tool	grepper	0m Args: { "Expression": "do_ip_vs_get_ctl", "PathPrefix": "net/netfilter/ipvs" } Results: { "Output": "net/netfilter/ipvs/ip_vs_ctl.c=3781=static int\nnet/netfilter/ipvs/ip_vs_ctl.c:3782:do_ip_vs_get_ctl(struct sock sk, int cmd, void __user user, int *len)\nnet/netfilter/ipvs/ip_vs_ctl.c-3783-{\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=3951=static struct nf_sockopt_ops ip_vs_sockopts = {\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3957-\t.get_optmax\t= IP_VS_SO_GET_MAX+1,\nnet/netfilter/ipvs/ip_vs_ctl.c:3958:\t.get\t\t= do_ip_vs_get_ctl,\nnet/netfilter/ipvs/ip_vs_ctl.c-3959-\t.owner\t\t= THIS_MODULE,\n" }
75/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 37105 output: 44 thoughts: 33 Thoughts: Okay, let's dive into this. Here's how I'd approach that snippet of code, assuming I'm an expert in this field: Diving into `ip_vs_ctl.c` Alright, time to get my hands dirty. I need to refresh my memory on the specifics of the `do_ip_vs_get_ctl` function within the `ip_vs_ctl.c` file in the netfilter/ipvs directory. I know this file houses crucial control functions for the IPVS (IP Virtual Server) subsystem, and specifically, I suspect this function might be the heart of how we retrieve control information. I'll need to understand what specific control parameters it handles, how it interacts with the internal IPVS data structures, and how it handles potential errors. Is it primarily for getting global stats, or perhaps details about a specific virtual server, real server, or connection entry? Context is key. I'll be looking for things like mutexes, locking, memory allocation, and obviously, the data it returns. Understanding this retrieval process is essential for troubleshooting, monitoring, and potentially even extending the IPVS functionality.
76/3	2026/09/12 02:38	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_ctl.c", "FirstLine": 3780, "LineCount": 80 } Results: { "Contents": "3780:\t\n3781:\tstatic int\n3782:\tdo_ip_vs_get_ctl(struct sock sk, int cmd, void __user user, int len)\n3783:\t{\n3784:\t\tunsigned char arg[MAX_GET_ARGLEN];\n3785:\t\tint ret = 0;\n3786:\t\tunsigned int copylen;\n3787:\t\tstruct net net = sock_net(sk);\n3788:\t\tstruct netns_ipvs ipvs = net_ipvs(net);\n3789:\t\n3790:\t\tBUG_ON(!net);\n3791:\t\tBUILD_BUG_ON(sizeof(arg) \u003e 255);\n3792:\t\tif (!ns_capable(sock_net(sk)-\u003euser_ns, CAP_NET_ADMIN))\n3793:\t\t\treturn -EPERM;\n3794:\t\n3795:\t\tif (cmd \u003c IP_VS_BASE_CTL \|\| cmd \u003e IP_VS_SO_GET_MAX)\n3796:\t\t\treturn -EINVAL;\n3797:\t\n3798:\t\tcopylen = get_arglen[CMDID(cmd)];\n3799:\t\tif (len \u003c (int) copylen) {\n3800:\t\t\tIP_VS_DBG(1, \"get_ctl: len %d \u003c %u\\n\", len, copylen);\n3801:\t\t\treturn -EINVAL;\n3802:\t\t}\n3803:\t\n3804:\t\tif (copy_from_user(arg, user, copylen) != 0)\n3805:\t\t\treturn -EFAULT;\n3806:\t\t/\n3807:\t\t * Handle daemons first since it has its own locking\n3808:\t\t /\n3809:\t\tif (cmd == IP_VS_SO_GET_DAEMON) {\n3810:\t\t\tstruct ip_vs_daemon_user d[2];\n3811:\t\n3812:\t\t\tmemset(\u0026d, 0, sizeof(d));\n3813:\t\t\tmutex_lock(\u0026ipvs-\u003esync_mutex);\n3814:\t\t\tif (ipvs-\u003esync_state \u0026 IP_VS_STATE_MASTER) {\n3815:\t\t\t\td[0].state = IP_VS_STATE_MASTER;\n3816:\t\t\t\tstrscpy(d[0].mcast_ifn, ipvs-\u003emcfg.mcast_ifn,\n3817:\t\t\t\t\tsizeof(d[0].mcast_ifn));\n3818:\t\t\t\td[0].syncid = ipvs-\u003emcfg.syncid;\n3819:\t\t\t}\n3820:\t\t\tif (ipvs-\u003esync_state \u0026 IP_VS_STATE_BACKUP) {\n3821:\t\t\t\td[1].state = IP_VS_STATE_BACKUP;\n3822:\t\t\t\tstrscpy(d[1].mcast_ifn, ipvs-\u003ebcfg.mcast_ifn,\n3823:\t\t\t\t\tsizeof(d[1].mcast_ifn));\n3824:\t\t\t\td[1].syncid = ipvs-\u003ebcfg.syncid;\n3825:\t\t\t}\n3826:\t\t\tif (copy_to_user(user, \u0026d, sizeof(d)) != 0)\n3827:\t\t\t\tret = -EFAULT;\n3828:\t\t\tmutex_unlock(\u0026ipvs-\u003esync_mutex);\n3829:\t\t\treturn ret;\n3830:\t\t}\n3831:\t\n3832:\t\tif (cmd == IP_VS_SO_GET_SERVICES) {\n3833:\t\t\tstruct ip_vs_get_services get;\n3834:\t\t\tsize_t size;\n3835:\t\n3836:\t\t\tget = (struct ip_vs_get_services )arg;\n3837:\t\t\tsize = struct_size(get, entrytable, get-\u003enum_services);\n3838:\t\t\tif (len != size) {\n3839:\t\t\t\tpr_err(\"length: %u != %zu\\n\", len, size);\n3840:\t\t\t\treturn -EINVAL;\n3841:\t\t\t}\n3842:\t\t\t/ Prevent modifications to the list with services.\n3843:\t\t\t * Try reverse locking, so that we do not hold the mutex\n3844:\t\t\t * while waiting for semaphore.\n3845:\t\t\t */\n3846:\t\t\twhile (1) {\n3847:\t\t\t\tret = down_read_killable(\u0026ipvs-\u003esvc_resize_sem);\n3848:\t\t\t\tif (ret \u003c 0)\n3849:\t\t\t\t\treturn ret;\n3850:\t\t\t\tif (mutex_trylock(\u0026ipvs-\u003eservice_mutex))\n3851:\t\t\t\t\tbreak;\n3852:\t\t\t\tup_read(\u0026ipvs-\u003esvc_resize_sem);\n3853:\t\t\t\tcond_resched();\n3854:\t\t\t}\n3855:\t\t\tret = __ip_vs_get_service_entries(ipvs, get, user);\n3856:\t\t\tup_read(\u0026ipvs-\u003esvc_resize_sem);\n3857:\t\t\tmutex_unlock(\u0026ipvs-\u003eservice_mutex);\n3858:\t\t\treturn ret;\n3859:\t\t}\n" }
77/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 38760 output: 44 thoughts: 46 Thoughts: Here's my take on those lines of code, focusing on the potential implications: Analyzing `__ip_vs_get_service_entries` and `IP_VS_SO_GET_SERVICE` Okay, so I'm looking at `__ip_vs_get_service_entries` in conjunction with `IP_VS_SO_GET_SERVICE`. I'm immediately interested because of the "get" operation on service entries. This hints at the core functionality: retrieving information about virtual server configurations, probably the associated reals or just the configuration itself. My gut says this has to do with how the system exposes its state to user space. `IP_VS_SO_GET_SERVICE` sounds like the socket option used to trigger the retrieval, likely by a tool like `ipvsadm`. Let me zero in on lines 3860-3910. I'll bet those lines contain the crucial logic. I expect I'll find the following: the validation and handling of the socket option, the mechanism for traversing the internal data structures that hold the service entries, and the serialization of that data into a format that can be sent back to the user space process. Depending on the design, I might find protection of the data structures with locks to ensure atomicity. I might also find the handling of various error conditions and the return codes to signal them.
78/3	2026/09/12 02:38	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_ctl.c", "FirstLine": 3860, "LineCount": 50 } Results: { "Contents": "3860:\t\n3861:\t\tmutex_lock(\u0026ipvs-\u003eservice_mutex);\n3862:\t\tswitch (cmd) {\n3863:\t\tcase IP_VS_SO_GET_VERSION:\n3864:\t\t{\n3865:\t\t\tchar buf[64];\n3866:\t\n3867:\t\t\tsprintf(buf, \"IP Virtual Server version %d.%d.%d (size=%d)\",\n3868:\t\t\t\tNVERSION(IP_VS_VERSION_CODE), get_conn_tab_size(ipvs));\n3869:\t\t\tif (copy_to_user(user, buf, strlen(buf)+1) != 0) {\n3870:\t\t\t\tret = -EFAULT;\n3871:\t\t\t\tgoto out;\n3872:\t\t\t}\n3873:\t\t\tlen = strlen(buf)+1;\n3874:\t\t}\n3875:\t\tbreak;\n3876:\t\n3877:\t\tcase IP_VS_SO_GET_INFO:\n3878:\t\t{\n3879:\t\t\tstruct ip_vs_getinfo info;\n3880:\t\n3881:\t\t\tinfo.version = IP_VS_VERSION_CODE;\n3882:\t\t\tinfo.size = get_conn_tab_size(ipvs);\n3883:\t\t\tinfo.num_services =\n3884:\t\t\t\tatomic_read(\u0026ipvs-\u003enum_services[IP_VS_AF_INET]);\n3885:\t\t\tif (copy_to_user(user, \u0026info, sizeof(info)) != 0)\n3886:\t\t\t\tret = -EFAULT;\n3887:\t\t}\n3888:\t\tbreak;\n3889:\t\n3890:\t\tcase IP_VS_SO_GET_SERVICE:\n3891:\t\t{\n3892:\t\t\tstruct ip_vs_service_entry entry;\n3893:\t\t\tstruct ip_vs_service svc;\n3894:\t\t\tunion nf_inet_addr addr;\n3895:\t\n3896:\t\t\tentry = (struct ip_vs_service_entry )arg;\n3897:\t\t\taddr.ip = entry-\u003eaddr;\n3898:\t\t\trcu_read_lock();\n3899:\t\t\tif (entry-\u003efwmark)\n3900:\t\t\t\tsvc = __ip_vs_svc_fwm_find(ipvs, AF_INET, entry-\u003efwmark);\n3901:\t\t\telse\n3902:\t\t\t\tsvc = __ip_vs_service_find(ipvs, AF_INET,\n3903:\t\t\t\t\t\t\t entry-\u003eprotocol, \u0026addr,\n3904:\t\t\t\t\t\t\t entry-\u003eport);\n3905:\t\t\trcu_read_unlock();\n3906:\t\t\tif (svc) {\n3907:\t\t\t\tip_vs_copy_service(entry, svc);\n3908:\t\t\t\tif (copy_to_user(user, entry, sizeof(*entry)) != 0)\n3909:\t\t\t\t\tret = -EFAULT;\n" }
79/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 39910 output: 34 thoughts: 26 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience: Tracing the `ip_vs_copy_service` Function Okay, so I'm looking at `ip_vs_copy_service`. The name is suggestive – clearly related to IP Virtual Server (IPVS) and some kind of data copying operation within a service context. My first instinct is to locate the function's definition. Where is this function declared? I need to understand its signature, what data structures it operates on, and, most importantly, where it's used within the IPVS framework. Is it core to connection tracking, NAT manipulation, scheduler interaction, or perhaps related to health checks? The goal is to quickly pinpoint its role and contribution to the overall system's functionality. This is a crucial first step in any deep dive.
80/3	2026/09/12 02:38	tool	grepper	0m Args: { "Expression": "ip_vs_copy_service", "PathPrefix": "net/netfilter/ipvs" } Results: { "Output": "net/netfilter/ipvs/ip_vs_ctl.c=3622=static void\nnet/netfilter/ipvs/ip_vs_ctl.c:3623:ip_vs_copy_service(struct ip_vs_service_entry dst, struct ip_vs_service src)\nnet/netfilter/ipvs/ip_vs_ctl.c-3624-{\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=3645=__ip_vs_get_service_entries(struct netns_ipvs ipvs,\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3667-\t\t\tmemset(\u0026entry, 0, sizeof(entry));\nnet/netfilter/ipvs/ip_vs_ctl.c:3668:\t\t\tip_vs_copy_service(\u0026entry, svc);\nnet/netfilter/ipvs/ip_vs_ctl.c-3669-\t\t\tif (copy_to_user(\u0026uptr-\u003eentrytable[count],\n--\nnet/netfilter/ipvs/ip_vs_ctl.c=3782=do_ip_vs_get_ctl(struct sock sk, int cmd, void __user user, int len)\n--\nnet/netfilter/ipvs/ip_vs_ctl.c-3906-\t\tif (svc) {\nnet/netfilter/ipvs/ip_vs_ctl.c:3907:\t\t\tip_vs_copy_service(entry, svc);\nnet/netfilter/ipvs/ip_vs_ctl.c-3908-\t\t\tif (copy_to_user(user, entry, sizeof(*entry)) != 0)\n" }
81/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 40570 output: 44 thoughts: 13 Thoughts: Okay, let's dive into this. Here's how I'd approach summarizing the "Thoughts" based on my expertise: Checking `ip_vs_copy_service` Alright, so the task at hand is to understand or examine something related to `ip_vs_copy_service`. Immediately, I'm thinking about the implications. `ip_vs` hints at IP Virtual Server, a critical component in load balancing, particularly in the Linux kernel. The "copy" aspect is interesting. Does this refer to a service that copies traffic, replicates data, or something else entirely in the context of IPVS? My immediate internal questions are: What is the context? What is the function of the service in relation to IP Virtual Server? What is it intended to do? Does this refer to a kernel module or a user-space utility? I'm already mentally running through the typical IPVS setup process, thinking about connection tracking, forwarding methods (NAT, DR, TUN), health checks, and persistence. If `ip_vs_copy_service` is involved, I want to immediately consider how it interacts with these core IPVS functionalities. Is it a custom add-on? Something from a specific distribution? Or a third-party implementation that builds upon the IPVS framework? Understanding the specifics is important. Now I'll need to know where I can check the code and related docs.
82/3	2026/09/12 02:38	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_ctl.c", "FirstLine": 3620, "LineCount": 25 } Results: { "Contents": "3620:\t\n3621:\t\n3622:\tstatic void\n3623:\tip_vs_copy_service(struct ip_vs_service_entry dst, struct ip_vs_service src)\n3624:\t{\n3625:\t\tstruct ip_vs_scheduler sched;\n3626:\t\tstruct ip_vs_kstats kstats;\n3627:\t\tchar sched_name;\n3628:\t\n3629:\t\tsched = rcu_dereference_protected(src-\u003escheduler, 1);\n3630:\t\tsched_name = sched ? sched-\u003ename : \"none\";\n3631:\t\tdst-\u003eprotocol = src-\u003eprotocol;\n3632:\t\tdst-\u003eaddr = src-\u003eaddr.ip;\n3633:\t\tdst-\u003eport = src-\u003eport;\n3634:\t\tdst-\u003efwmark = src-\u003efwmark;\n3635:\t\tstrscpy(dst-\u003esched_name, sched_name, sizeof(dst-\u003esched_name));\n3636:\t\tdst-\u003eflags = src-\u003eflags;\n3637:\t\tdst-\u003etimeout = src-\u003etimeout / HZ;\n3638:\t\tdst-\u003enetmask = src-\u003enetmask;\n3639:\t\tdst-\u003enum_dests = src-\u003enum_dests;\n3640:\t\tip_vs_copy_stats(\u0026kstats, \u0026src-\u003estats);\n3641:\t\tip_vs_export_stats_user(\u0026dst-\u003estats, \u0026kstats);\n3642:\t}\n3643:\t\n3644:\tstatic inline int\n" }
83/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 41332 output: 36 thoughts: 678 Thoughts: Analyzing the Impact of the New TCP Security Flag Okay, hold on a second. I need to be methodical here. The provided text details a review of code changes related to a new TCP security flag, `IP_VS_CONN_F_SECURE_TCP`, within the IPVS (IP Virtual Server) subsystem. I was initially worried about potential vulnerabilities related to user-space input, but after carefully re-examining `do_ip_vs_get_ctl`, it seems the arguments being copied from user space (`copy_from_user`) and subsequently passed to related routines are not directly targeted by the patch. No immediate red flags there. Let's break down what was changed: 1. Header Definitions: The header `include/uapi/linux/ip_vs.h` now includes the defines for the new security flag (`IP_VS_SVC_F_SECURE_TCP`, `IP_VS_CONN_F_SECURE_TCP`), and that flag has been added to `IP_VS_CONN_F_BACKUP_MASK`. This is expected for adding a new feature. 2. Core Logic: The core file `ip_vs_core.c` has a function `ip_vs_conn_secure_tcp_flags(struct ip_vs_service svc)` defined and, crucially, it's integrated into connection creation (`ip_vs_conn_new`) within `ip_vs_sched_persist`, `ip_vs_schedule`, `ip_vs_leave`, and `ip_vs_new_conn_out`. This propagates the security flag from the service to the connection. 3. FTP Handling:* The FTP module (`ip_vs_ftp.c`) correctly propagates the security flag to new connections when handling FTP traffic, using `ip_vs_conn_new`. 4. TCP State Transitions: In `ip_vs_proto_tcp.c`, `set_tcp_state` now conditionally uses a different TCP state table (`tcp_states_dos`) based on the presence of the `IP_VS_CONN_F_SECURE_TCP` flag. This is the part that really matters to me, as it alters the state transitions. This has a high likelihood of being correct, but requires further in-depth review. 5. Selftests: The addition of selftests is good. This makes it easier to verify the behavior of the patch. Now, a critical question arises: could this new security flag, and its integration, introduce any memory safety issues, particularly related to the synchronization daemon or the backup daemon? This is a key area for further inspection. I need to delve into `ip_vs_sync.c` and specifically look for how connection information is exchanged between daemons and whether the new security flag is properly handled. I'm going to search for instances of `IP_VS_CONN_F_SECURE_TCP` or any other related flag manipulations in that file. That will reveal the biggest potential for problems. I can already see a few areas I need to focus on for additional scrutiny.
84/3	2026/09/12 02:38	tool	grepper	0m Args: { "Expression": "flags", "PathPrefix": "net/netfilter/ipvs/ip_vs_sync.c" } Results: { "Output": "net/netfilter/ipvs/ip_vs_sync.c=70=struct ip_vs_sync_conn_v0 {\n--\nnet/netfilter/ipvs/ip_vs_sync.c-82-\t/* Flags and state transition /\nnet/netfilter/ipvs/ip_vs_sync.c:83:\t__be16 flags; / status flags /\nnet/netfilter/ipvs/ip_vs_sync.c-84-\t__be16 state; / state info /\n--\nnet/netfilter/ipvs/ip_vs_sync.c=132=struct ip_vs_sync_v4 {\n--\nnet/netfilter/ipvs/ip_vs_sync.c-136-\t/ Flags and state transition /\nnet/netfilter/ipvs/ip_vs_sync.c:137:\t__be32\t\t\tflags;\t\t/ status flags /\nnet/netfilter/ipvs/ip_vs_sync.c-138-\t__be16\t\t\tstate;\t\t/ state info \t/\n--\nnet/netfilter/ipvs/ip_vs_sync.c=154=struct ip_vs_sync_v6 {\n--\nnet/netfilter/ipvs/ip_vs_sync.c-158-\t/ Flags and state transition /\nnet/netfilter/ipvs/ip_vs_sync.c:159:\t__be32\t\t\tflags;\t\t/ status flags /\nnet/netfilter/ipvs/ip_vs_sync.c-160-\t__be16\t\t\tstate;\t\t/ state info \t/\n--\nnet/netfilter/ipvs/ip_vs_sync.c=441=static inline bool in_persistence(struct ip_vs_conn cp)\n--\nnet/netfilter/ipvs/ip_vs_sync.c-443-\tfor (cp = cp-\u003econtrol; cp; cp = cp-\u003econtrol) {\nnet/netfilter/ipvs/ip_vs_sync.c:444:\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE)\nnet/netfilter/ipvs/ip_vs_sync.c-445-\t\t\treturn true;\n--\nnet/netfilter/ipvs/ip_vs_sync.c=459=static int ip_vs_sync_conn_needed(struct netns_ipvs ipvs,\n--\nnet/netfilter/ipvs/ip_vs_sync.c-469-\t/ Check if we sync in current state /\nnet/netfilter/ipvs/ip_vs_sync.c:470:\tif (unlikely(cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE))\nnet/netfilter/ipvs/ip_vs_sync.c-471-\t\tforce = 0;\n--\nnet/netfilter/ipvs/ip_vs_sync.c-521-\tif (sync_period \u003e 0) {\nnet/netfilter/ipvs/ip_vs_sync.c:522:\t\tif (!(cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE) \u0026\u0026\nnet/netfilter/ipvs/ip_vs_sync.c-523-\t\t pkts % sync_period != sysctl_sync_threshold(ipvs))\n--\nnet/netfilter/ipvs/ip_vs_sync.c=539=static void ip_vs_sync_conn_v0(struct netns_ipvs ipvs, struct ip_vs_conn cp,\n--\nnet/netfilter/ipvs/ip_vs_sync.c-551-\t/ Do not sync ONE PACKET /\nnet/netfilter/ipvs/ip_vs_sync.c:552:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_ONE_PACKET)\nnet/netfilter/ipvs/ip_vs_sync.c-553-\t\treturn;\n--\nnet/netfilter/ipvs/ip_vs_sync.c-566-\tbuff = ms-\u003esync_buff;\nnet/netfilter/ipvs/ip_vs_sync.c:567:\tlen = (cp-\u003eflags \u0026 IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :\nnet/netfilter/ipvs/ip_vs_sync.c-568-\t\tSIMPLE_CONN_SIZE;\n--\nnet/netfilter/ipvs/ip_vs_sync.c-599-\ts-\u003edaddr = cp-\u003edaddr.ip;\nnet/netfilter/ipvs/ip_vs_sync.c:600:\ts-\u003eflags = htons(cp-\u003eflags \u0026 ~IP_VS_CONN_F_HASHED);\nnet/netfilter/ipvs/ip_vs_sync.c-601-\ts-\u003estate = htons(cp-\u003estate);\nnet/netfilter/ipvs/ip_vs_sync.c:602:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_SEQ_MASK) {\nnet/netfilter/ipvs/ip_vs_sync.c-603-\t\tstruct ip_vs_sync_conn_options opt =\n--\nnet/netfilter/ipvs/ip_vs_sync.c-615-\tif (cp) {\nnet/netfilter/ipvs/ip_vs_sync.c:616:\t\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE)\nnet/netfilter/ipvs/ip_vs_sync.c-617-\t\t\tpkts = atomic_inc_return(\u0026cp-\u003ein_pkts);\n--\nnet/netfilter/ipvs/ip_vs_sync.c=629=void ip_vs_sync_conn(struct netns_ipvs ipvs, struct ip_vs_conn cp, int pkts)\n--\nnet/netfilter/ipvs/ip_vs_sync.c-644-\t/* Do not sync ONE PACKET /\nnet/netfilter/ipvs/ip_vs_sync.c:645:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_ONE_PACKET)\nnet/netfilter/ipvs/ip_vs_sync.c-646-\t\tgoto control;\n--\nnet/netfilter/ipvs/ip_vs_sync.c-676-\nnet/netfilter/ipvs/ip_vs_sync.c:677:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_SEQ_MASK)\nnet/netfilter/ipvs/ip_vs_sync.c-678-\t\tlen += sizeof(struct ip_vs_sync_conn_options) + 2;\n--\nnet/netfilter/ipvs/ip_vs_sync.c-722-\ts-\u003ev4.ver_size = htons(len \u0026 SVER_MASK);\t/ Version 0 /\nnet/netfilter/ipvs/ip_vs_sync.c:723:\ts-\u003ev4.flags = htonl(cp-\u003eflags \u0026 ~IP_VS_CONN_F_HASHED);\nnet/netfilter/ipvs/ip_vs_sync.c-724-\ts-\u003ev4.state = htons(cp-\u003estate);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-746-\t}\nnet/netfilter/ipvs/ip_vs_sync.c:747:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_SEQ_MASK) {\nnet/netfilter/ipvs/ip_vs_sync.c-748-\t\t(p++) = IPVS_OPT_SEQ_DATA;\n--\nnet/netfilter/ipvs/ip_vs_sync.c-776-\t\treturn;\nnet/netfilter/ipvs/ip_vs_sync.c:777:\tif (cp-\u003eflags \u0026 IP_VS_CONN_F_TEMPLATE)\nnet/netfilter/ipvs/ip_vs_sync.c-778-\t\tpkts = atomic_inc_return(\u0026cp-\u003ein_pkts);\n--\nnet/netfilter/ipvs/ip_vs_sync.c=841=static void ip_vs_proc_conn(struct netns_ipvs ipvs, struct ip_vs_conn_param param,\nnet/netfilter/ipvs/ip_vs_sync.c:842:\t\t\t unsigned int flags, unsigned int state,\nnet/netfilter/ipvs/ip_vs_sync.c-843-\t\t\t unsigned int protocol, unsigned int type,\n--\nnet/netfilter/ipvs/ip_vs_sync.c-850-\nnet/netfilter/ipvs/ip_vs_sync.c:851:\tif (!(flags \u0026 IP_VS_CONN_F_TEMPLATE)) {\nnet/netfilter/ipvs/ip_vs_sync.c-852-\t\tcp = ip_vs_conn_in_get(param);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-854-\t\t\t !ip_vs_addr_equal(cp-\u003edaf, \u0026cp-\u003edaddr, daddr))) {\nnet/netfilter/ipvs/ip_vs_sync.c:855:\t\t\tif (!(flags \u0026 IP_VS_CONN_F_INACTIVE)) {\nnet/netfilter/ipvs/ip_vs_sync.c-856-\t\t\t\tip_vs_conn_expire_now(cp);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-878-\t\tspin_lock_bh(\u0026cp-\u003elock);\nnet/netfilter/ipvs/ip_vs_sync.c:879:\t\tif ((cp-\u003eflags ^ flags) \u0026 IP_VS_CONN_F_INACTIVE \u0026\u0026\nnet/netfilter/ipvs/ip_vs_sync.c:880:\t\t !(flags \u0026 IP_VS_CONN_F_TEMPLATE) \u0026\u0026 dest) {\nnet/netfilter/ipvs/ip_vs_sync.c:881:\t\t\tif (flags \u0026 IP_VS_CONN_F_INACTIVE)\nnet/netfilter/ipvs/ip_vs_sync.c-882-\t\t\t\tatomic_dec(\u0026dest-\u003eactiveconns);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-885-\t\t}\nnet/netfilter/ipvs/ip_vs_sync.c:886:\t\tflags \u0026= IP_VS_CONN_F_BACKUP_UPD_MASK;\nnet/netfilter/ipvs/ip_vs_sync.c:887:\t\tflags \|= cp-\u003eflags \u0026 ~IP_VS_CONN_F_BACKUP_UPD_MASK;\nnet/netfilter/ipvs/ip_vs_sync.c:888:\t\tcp-\u003eflags = flags;\nnet/netfilter/ipvs/ip_vs_sync.c-889-\t\tspin_unlock_bh(\u0026cp-\u003elock);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-905-\t\t\t\t param-\u003evaddr, param-\u003evport, protocol,\nnet/netfilter/ipvs/ip_vs_sync.c:906:\t\t\t\t fwmark, flags);\nnet/netfilter/ipvs/ip_vs_sync.c-907-\nnet/netfilter/ipvs/ip_vs_sync.c:908:\t\tcp = ip_vs_conn_new(param, type, daddr, dport, flags, dest,\nnet/netfilter/ipvs/ip_vs_sync.c-909-\t\t\t\t fwmark);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-915-\t\t}\nnet/netfilter/ipvs/ip_vs_sync.c:916:\t\tif (!(flags \u0026 IP_VS_CONN_F_TEMPLATE))\nnet/netfilter/ipvs/ip_vs_sync.c-917-\t\t\tkfree(param-\u003epe_data);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-943-\t\tpd = ip_vs_proto_data_get(ipvs, protocol);\nnet/netfilter/ipvs/ip_vs_sync.c:944:\t\tif (!(flags \u0026 IP_VS_CONN_F_TEMPLATE) \u0026\u0026 pd \u0026\u0026 pd-\u003etimeout_table)\nnet/netfilter/ipvs/ip_vs_sync.c-945-\t\t\tcp-\u003etimeout = pd-\u003etimeout_table[state];\n--\nnet/netfilter/ipvs/ip_vs_sync.c=955=static void ip_vs_process_message_v0(struct netns_ipvs ipvs, const char buffer,\n--\nnet/netfilter/ipvs/ip_vs_sync.c-967-\tfor (i=0; i\u003cm-\u003enr_conns; i++) {\nnet/netfilter/ipvs/ip_vs_sync.c:968:\t\tunsigned int flags, state;\nnet/netfilter/ipvs/ip_vs_sync.c-969-\n--\nnet/netfilter/ipvs/ip_vs_sync.c-974-\t\ts = (struct ip_vs_sync_conn_v0 ) p;\nnet/netfilter/ipvs/ip_vs_sync.c:975:\t\tflags = ntohs(s-\u003eflags) \| IP_VS_CONN_F_SYNC;\nnet/netfilter/ipvs/ip_vs_sync.c:976:\t\tflags \u0026= ~IP_VS_CONN_F_HASHED;\nnet/netfilter/ipvs/ip_vs_sync.c:977:\t\tif (flags \u0026 IP_VS_CONN_F_SEQ_MASK) {\nnet/netfilter/ipvs/ip_vs_sync.c-978-\t\t\topt = (struct ip_vs_sync_conn_options )\u0026s[1];\n--\nnet/netfilter/ipvs/ip_vs_sync.c-989-\t\tstate = ntohs(s-\u003estate);\nnet/netfilter/ipvs/ip_vs_sync.c:990:\t\tif (!(flags \u0026 IP_VS_CONN_F_TEMPLATE)) {\nnet/netfilter/ipvs/ip_vs_sync.c-991-\t\t\tpp = ip_vs_proto_get(s-\u003eprotocol);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1014-\t\t/* Send timeout as Zero /\nnet/netfilter/ipvs/ip_vs_sync.c:1015:\t\tip_vs_proc_conn(ipvs, \u0026param, flags, state, s-\u003eprotocol, AF_INET,\nnet/netfilter/ipvs/ip_vs_sync.c-1016-\t\t\t\t(union nf_inet_addr )\u0026s-\u003edaddr, s-\u003edport,\n--\nnet/netfilter/ipvs/ip_vs_sync.c=1024=static inline int ip_vs_proc_seqopt(__u8 p, unsigned int plen,\nnet/netfilter/ipvs/ip_vs_sync.c:1025:\t\t\t\t __u32 opt_flags,\nnet/netfilter/ipvs/ip_vs_sync.c-1026-\t\t\t\t struct ip_vs_sync_conn_options opt)\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1035-\t}\nnet/netfilter/ipvs/ip_vs_sync.c:1036:\tif (opt_flags \u0026 IPVS_OPT_F_SEQ_DATA) {\nnet/netfilter/ipvs/ip_vs_sync.c-1037-\t\tIP_VS_DBG(2, \"BACKUP, conn options found twice\\n\");\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1041-\tntoh_seq(\u0026topt-\u003eout_seq, \u0026opt-\u003eout_seq);\nnet/netfilter/ipvs/ip_vs_sync.c:1042:\topt_flags \|= IPVS_OPT_F_SEQ_DATA;\nnet/netfilter/ipvs/ip_vs_sync.c-1043-\treturn 0;\n--\nnet/netfilter/ipvs/ip_vs_sync.c=1046=static int ip_vs_proc_str(__u8 p, unsigned int plen, unsigned int data_len,\nnet/netfilter/ipvs/ip_vs_sync.c-1047-\t\t\t __u8 data, unsigned int maxlen,\nnet/netfilter/ipvs/ip_vs_sync.c:1048:\t\t\t __u32 opt_flags, __u32 flag)\nnet/netfilter/ipvs/ip_vs_sync.c-1049-{\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1053-\t}\nnet/netfilter/ipvs/ip_vs_sync.c:1054:\tif (opt_flags \u0026 flag) {\nnet/netfilter/ipvs/ip_vs_sync.c-1055-\t\tIP_VS_DBG(2, \"BACKUP, Par.data found twice 0x%x\\n\", flag);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1059-\tdata = p;\nnet/netfilter/ipvs/ip_vs_sync.c:1060:\topt_flags \|= flag;\nnet/netfilter/ipvs/ip_vs_sync.c-1061-\treturn 0;\n--\nnet/netfilter/ipvs/ip_vs_sync.c=1066=static inline int ip_vs_proc_sync_conn(struct netns_ipvs ipvs, __u8 p, __u8 msg_end)\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1071-\tstruct ip_vs_conn_param param;\nnet/netfilter/ipvs/ip_vs_sync.c:1072:\t__u32 flags;\nnet/netfilter/ipvs/ip_vs_sync.c-1073-\tunsigned int af, state, pe_data_len=0, pe_name_len=0;\nnet/netfilter/ipvs/ip_vs_sync.c-1074-\t__u8 pe_data=NULL, pe_name=NULL;\nnet/netfilter/ipvs/ip_vs_sync.c:1075:\t__u32 opt_flags=0;\nnet/netfilter/ipvs/ip_vs_sync.c-1076-\tint retc=0;\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1112-\t\tcase IPVS_OPT_SEQ_DATA:\nnet/netfilter/ipvs/ip_vs_sync.c:1113:\t\t\tif (ip_vs_proc_seqopt(p, plen, \u0026opt_flags, \u0026opt))\nnet/netfilter/ipvs/ip_vs_sync.c-1114-\t\t\t\treturn -50;\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1118-\t\t\tif (ip_vs_proc_str(p, plen, \u0026pe_data_len, \u0026pe_data,\nnet/netfilter/ipvs/ip_vs_sync.c:1119:\t\t\t\t\t IP_VS_PEDATA_MAXLEN, \u0026opt_flags,\nnet/netfilter/ipvs/ip_vs_sync.c-1120-\t\t\t\t\t IPVS_OPT_F_PE_DATA))\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1125-\t\t\tif (ip_vs_proc_str(p, plen,\u0026pe_name_len, \u0026pe_name,\nnet/netfilter/ipvs/ip_vs_sync.c:1126:\t\t\t\t\t IP_VS_PENAME_MAXLEN, \u0026opt_flags,\nnet/netfilter/ipvs/ip_vs_sync.c-1127-\t\t\t\t\t IPVS_OPT_F_PE_NAME))\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1142-\nnet/netfilter/ipvs/ip_vs_sync.c:1143:\t/* Get flags and Mask off unsupported /\nnet/netfilter/ipvs/ip_vs_sync.c:1144:\tflags = ntohl(s-\u003ev4.flags) \u0026 IP_VS_CONN_F_BACKUP_MASK;\nnet/netfilter/ipvs/ip_vs_sync.c:1145:\tflags \|= IP_VS_CONN_F_SYNC;\nnet/netfilter/ipvs/ip_vs_sync.c-1146-\tstate = ntohs(s-\u003ev4.state);\nnet/netfilter/ipvs/ip_vs_sync.c-1147-\nnet/netfilter/ipvs/ip_vs_sync.c:1148:\tif (!(flags \u0026 IP_VS_CONN_F_TEMPLATE)) {\nnet/netfilter/ipvs/ip_vs_sync.c-1149-\t\tpp = ip_vs_proto_get(s-\u003ev4.protocol);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1173-\tif (af == AF_INET)\nnet/netfilter/ipvs/ip_vs_sync.c:1174:\t\tip_vs_proc_conn(ipvs, \u0026param, flags, state, s-\u003ev4.protocol, af,\nnet/netfilter/ipvs/ip_vs_sync.c-1175-\t\t\t\t(union nf_inet_addr )\u0026s-\u003ev4.daddr, s-\u003ev4.dport,\nnet/netfilter/ipvs/ip_vs_sync.c-1176-\t\t\t\tntohl(s-\u003ev4.timeout), ntohl(s-\u003ev4.fwmark),\nnet/netfilter/ipvs/ip_vs_sync.c:1177:\t\t\t\t(opt_flags \u0026 IPVS_OPT_F_SEQ_DATA ? \u0026opt : NULL)\nnet/netfilter/ipvs/ip_vs_sync.c-1178-\t\t\t\t);\n--\nnet/netfilter/ipvs/ip_vs_sync.c-1180-\telse\nnet/netfilter/ipvs/ip_vs_sync.c:1181:\t\tip_vs_proc_conn(ipvs, \u0026param, flags, state, s-\u003ev6.protocol, af,\nnet/netfilter/ipvs/ip_vs_sync.c-1182-\t\t\t\t(union nf_inet_addr )\u0026s-\u003ev6.daddr, s-\u003ev6.dport,\nnet/netfilter/ipvs/ip_vs_sync.c-1183-\t\t\t\tntohl(s-\u003ev6.timeout), ntohl(s-\u003ev6.fwmark),\nnet/netfilter/ipvs/ip_vs_sync.c:1184:\t\t\t\t(opt_flags \u0026 IPVS_OPT_F_SEQ_DATA ? \u0026opt : NULL)\nnet/netfilter/ipvs/ip_vs_sync.c-1185-\t\t\t\t);\n--\nnet/netfilter/ipvs/ip_vs_sync.c=1569=ip_vs_send_async(struct socket sock, const char *buffer, const size_t length)\nnet/netfilter/ipvs/ip_vs_sync.c-1570-{\nnet/netfilter/ipvs/ip_vs_sync.c:1571:\tstruct msghdr\tmsg = {.msg_flags = MSG_DONTWAIT\|MSG_NOSIGNAL};\nnet/netfilter/ipvs/ip_vs_sync.c-1572-\tstruct kvec\tiov;\n" }
85/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 48484 output: 45 thoughts: 2156 Thoughts: KMSAN Evaluation: Secure TCP Connection Flag Propagation Okay, let's break this down. It looks like we're enabling a "secure TCP" capability within the IPVS connection tracking system. The core of this patch seems to be propagating a `IP_VS_CONN_F_SECURE_TCP` flag, and then utilizing it for decisions down the line. We're adding a service flag `IP_VS_SVC_F_SECURE_TCP` and a connection flag `IP_VS_CONN_F_SECURE_TCP`, which seems straightforward from a design perspective. My primary focus right now is to determine if this change triggers any of the KMSAN "NeedsKMSAN" criteria. I'm going through the list meticulously. First, let's see how the new flag is handled. The patch allows `IP_VS_CONN_F_SECURE_TCP` to be preserved in the `IP_VS_CONN_F_BACKUP_MASK`. This flag is sent across in the `ip_vs_sync_conn` function, which is fine as it uses `cp->flags`. Now, looking at the code, it seems that the new flag (`IP_VS_SVC_F_SECURE_TCP`) is checked in functions like `ip_vs_sched_persist`, `ip_vs_schedule`, `ip_vs_leave`, and `ip_vs_new_conn_out`. In these functions, a helper `ip_vs_conn_secure_tcp_flags` is introduced, to compute the connection flags based on a service flags. In the `ip_vs_ftp.c` it looks like the flags are transferred to new connections. Furthermore, in `ip_vs_proto_tcp.c`, `cp->flags & IP_VS_CONN_F_SECURE_TCP` is used to select the correct TCP state table to use. Now the critical part: let's evaluate each KMSAN "NeedsKMSAN" criterion: 1. Kernel Structures to User Space: The code modifies `include/uapi/linux/ip_vs.h` by introducing new flags in the header. Critically, I'm checking if the change impacts the size, layout, or content of any structures sent to user space via netlink, socket options, or other methods. `IPVS_SVC_ATTR_FLAGS` in netlink, are not changed, so it's not. `dst->flags = src->flags`, there are no new fields in the socket options. I don't see any evidence that the patch introduces uninitialized fields or changes padding. So, this criteria is a "no". 2. Conditional Logic/Uninitialized Variables: The branching logic relies on the new `svc->flags` and `cp->flags`. I need to be absolutely certain that these flags are initialized before being used. Looking at the code, both `svc` (in `ip_vs_add_service`) and `cp` (in `ip_vs_conn_new`) are properly initialized using `kzalloc` and `kmem_cache_alloc` and `flags` is explicitly assigned, so, I am confident they're initialized. The `cp->flags` is always initialized, so this criterion is also a "no". 3. Complex Data Structure Initialization: The patch doesn't introduce any new allocation or change the existing allocation methods, so no uninitialized fields are introduced. Thus this criteria is a "no". 4. Bounds Checks/Uninitialized Buffer Access: Let's think, in `set_tcp_state`, we check for `cp->flags & IP_VS_CONN_F_SECURE_TCP` to change to `table = tcp_states_dos`. The crucial part is to verify `tcp_states_dos` and the indexes: `state_off + state_idx` and `cp->state` are properly bounded. Both `tcp_states_dos` and `tcp_states` are static arrays and the indexes are checked, so it's a "no" as well. Based on this careful assessment, I don't see any evidence that this patch introduces or modifies code in a way that would trigger KMSAN-specific uninitialized memory risks. All criteria for NeedsKMSAN are negative. Therefore, I conclude this patch does not require `NeedsKMSAN=true`.
86/3	2026/09/12 02:38	tool	read-file	0m Args: { "File": "net/netfilter/ipvs/ip_vs_proto_tcp.c", "FirstLine": 400, "LineCount": 40 } Results: { "Contents": " 400:\t\treturn tcp_state_active_table[state];\n 401:\t}\n 402:\t\n 403:\tstatic struct tcp_states_t tcp_states[] = {\n 404:\t/\tINPUT /\n 405:\t/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA\t/\n 406:\t/syn/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},\n 407:\t/fin/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }},\n 408:\t/ack/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},\n 409:\t/rst/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }},\n 410:\t\n 411:\t/\tOUTPUT /\n 412:\t/ sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA\t/\n 413:\t/syn/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }},\n 414:\t/fin/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},\n 415:\t/ack/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},\n 416:\t/rst/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},\n 417:\t\n 418:\t/\tINPUT-ONLY /\n 419:\t/ sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA\t/\n 420:\t/syn/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},\n 421:\t/fin/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},\n 422:\t/ack/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},\n 423:\t/rst/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},\n 424:\t};\n 425:\t\n 426:\tstatic struct tcp_states_t tcp_states_dos[] = {\n 427:\t/\tINPUT /\n 428:\t/ sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA\t/\n 429:\t/syn/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }},\n 430:\t/fin/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }},\n 431:\t/ack/ {{sES, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }},\n 432:\t/rst/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},\n 433:\t\n 434:\t/\tOUTPUT /\n 435:\t/ sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA\t/\n 436:\t/syn/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }},\n 437:\t/fin/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},\n 438:\t/ack/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},\n 439:\t/rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},\n" }
87/3	2026/09/12 02:38	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 52906 output: 383 thoughts: 1237 Thoughts: KMSAN Analysis: IPVS Per-Connection Secure TCP Flag Okay, let's break this down. My analysis indicates that `NeedsKMSAN=false` for this patch. This is because the changes don't introduce or expose any uninitialized memory risks that KMSAN is specifically designed to catch. Here's my thought process: First, I examined what the patch actually does. It's introducing a new flag, `IP_VS_SVC_F_SECURE_TCP` for services and `IP_VS_CONN_F_SECURE_TCP` for connections within IPVS. This allows administrators to enable hardened TCP state transitions (using the `tcp_states_dos` table) on a per-service or per-connection basis, rather than just globally via the existing sysctl. Crucially, the connection flag is propagated during connection creation and synchronization and is included in the backup mask. There are also new selftests added to validate the functionality. Next, I meticulously checked for potential uninitialized memory risks. I confirmed that: 1. No new kernel-to-user data structures or fields are added, ensuring struct sizes and layouts are unchanged. 2. The existing flags are being used within existing integer fields – this means that the `svc->flags` and `cp->flags` are fully initialized when created. 3. All of the core structures involved (`ip_vs_service`, `ip_vs_conn`) are always fully initialized when used. Specifically, the structures are either `kzalloc`'d or fields are directly assigned during connection creation in `ip_vs_conn_new`. This guarantees that the flag reads and bitwise operations operate on fully initialized values. 4. The state tables (`tcp_states_dos` and `tcp_states`) are statically allocated and fully defined lookup tables. 5. There are absolutely no buffer length changes, any potential for information leaks, or new pathways for uninitialized memory to make its way to userspace. Finally, I contrasted the scope of KASAN (Kernel Address Sanitizer) and KMSAN (Kernel Memory Sanitizer). Any issues related to state transition logic, protocol handling, or potential concurrency issues that this patch introduces are already well-covered by KASAN or LOCKDEP. I concluded that KMSAN is not applicable here because there are no changes that introduce, or paths that operate on, uninitialized memory. The code is carefully initialized at every stage. Therefore, setting `NeedsKMSAN=false` is correct. The patch is functionally sound and safe from uninitialized memory reads.
88/3	2026/09/12 02:38	tool	set-results	0m Args: { "KMSANReasoning": "The patch introduces support for per-service hardened TCP state tracking (IP_VS_SVC_F_SECURE_TCP and IP_VS_CONN_F_SECURE_TCP) in IPVS. It allows connections belonging to a secure_tcp-enabled virtual service to use the existing hardened TCP state table (tcp_states_dos) rather than the default table, propagates this flag during connection creation and sync daemon handling (via IP_VS_CONN_F_BACKUP_MASK), and includes selftest utilities.\n\nAnalysis of uninitialized memory risk:\n1. Data structures \u0026 fields: The patch does not define new data structures or change the size, alignment, or padding of existing structures. It uses previously unused bit positions in existing integer fields (svc-\u003eflags and cp-\u003eflags).\n2. Initialization: Both struct ip_vs_service and struct ip_vs_conn have well-defined initialization routines (kzalloc and explicit member initialization in ip_vs_conn_new, respectively). Flags are initialized before use and propagated via standard bitwise operations on initialized variables.\n3. State lookup: The state table referenced (tcp_states_dos) is an existing, fully initialized static array of state transitions.\n4. User-space copies / info leaks: No uninitialized kernel memory or padding is exposed or copied to user space or across netlink/sockopt interfaces.\n\nAny potential defects in this patch (e.g., protocol state handling errors, synchronization or locking issues, or pointer dereferences) are functional bugs or within the scope of KASAN/LOCKDEP. There is no risk of uninitialized memory reads or information leaks detectable only by KMSAN. Therefore, a dedicated KMSAN session is not required.", "NeedsKMSAN": false } Results: { "KMSANReasoning": "The patch introduces support for per-service hardened TCP state tracking (IP_VS_SVC_F_SECURE_TCP and IP_VS_CONN_F_SECURE_TCP) in IPVS. It allows connections belonging to a secure_tcp-enabled virtual service to use the existing hardened TCP state table (tcp_states_dos) rather than the default table, propagates this flag during connection creation and sync daemon handling (via IP_VS_CONN_F_BACKUP_MASK), and includes selftest utilities.\n\nAnalysis of uninitialized memory risk:\n1. Data structures \u0026 fields: The patch does not define new data structures or change the size, alignment, or padding of existing structures. It uses previously unused bit positions in existing integer fields (svc-\u003eflags and cp-\u003eflags).\n2. Initialization: Both struct ip_vs_service and struct ip_vs_conn have well-defined initialization routines (kzalloc and explicit member initialization in ip_vs_conn_new, respectively). Flags are initialized before use and propagated via standard bitwise operations on initialized variables.\n3. State lookup: The state table referenced (tcp_states_dos) is an existing, fully initialized static array of state transitions.\n4. User-space copies / info leaks: No uninitialized kernel memory or padding is exposed or copied to user space or across netlink/sockopt interfaces.\n\nAny potential defects in this patch (e.g., protocol state handling errors, synchronization or locking issues, or pointer dereferences) are functional bugs or within the scope of KASAN/LOCKDEP. There is no risk of uninitialized memory reads or information leaks detectable only by KMSAN. Therefore, a dedicated KMSAN session is not required.", "NeedsKMSAN": false }

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Tool Calls Summary:
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