| Seq | Timestamp | Type | Name | Duration |
|---|---|---|---|---|
| 0/0 | 2026/08/12 13:24 | flow | patch-triage |
5mArgs:null Results: {
"EnableConfigs": [
"TIPC",
"TIPC_MEDIA_UDP"
],
"FocusSymbols": [
"tipc_sk_rcv",
"tipc_sk_mcast_rcv"
],
"KMSANReasoning": "The patch modifies the `tipc_sk_push_backlog` function to accept an additional `xmitq` argument, allowing it to splice the socket's write queue directly into the transmit queue when sending to the same node, rather than calling `tipc_node_xmit`. This is a control flow and queue management change. It does not introduce any new data structures, allocations, or copying of data to user space. Any potential bugs introduced by this change would be related to queue management (e.g., use-after-free, NULL pointer dereferences, or memory leaks), which are effectively detected by KASAN and standard kernel debugging tools. There is no risk of uninitialized memory usage or info-leaks that would require KMSAN.",
"NeedsKMSAN": false,
"Reasoning": "The patch modifies the TIPC socket receive and shutdown paths by changing how the socket backlog is pushed. It splices the transmit queue to a provided xmitq instead of transmitting directly when the destination is on the same node. This is a functional change in core TIPC socket logic that affects message transmission and queue management.",
"WorthFuzzing": true
} |
| 1/1 | 2026/08/12 13:24 | action | read-patch-diff |
0mArgs:null Results: {
"PatchDiff": "commit 4b0645d551d8f4a9d75e7dfc1b1420a76f2c7303\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Wed Aug 12 13:24:32 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/net/tipc/socket.c b/net/tipc/socket.c\nindex e564341e0216d..33d744dc514f5 100644\n--- a/net/tipc/socket.c\n+++ b/net/tipc/socket.c\n@@ -156,7 +156,8 @@ static int tipc_sk_insert(struct tipc_sock *tsk);\n static void tipc_sk_remove(struct tipc_sock *tsk);\n static int __tipc_sendstream(struct socket *sock, struct msghdr *m, size_t dsz);\n static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz);\n-static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack);\n+static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack,\n+\t\t\t\t struct sk_buff_head *xmitq);\n static int tipc_wait_for_connect(struct socket *sock, long *timeo_p);\n \n static const struct proto_ops packet_ops;\n@@ -560,7 +561,7 @@ static void __tipc_shutdown(struct socket *sock, int error)\n \t\t\t\t\t !tsk_conn_cong(tsk)));\n \n \t/* Push out delayed messages if in Nagle mode */\n-\ttipc_sk_push_backlog(tsk, false);\n+\ttipc_sk_push_backlog(tsk, false, NULL);\n \t/* Remove pending SYN */\n \t__skb_queue_purge(\u0026sk-\u003esk_write_queue);\n \n@@ -1267,8 +1268,10 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,\n \n /* tipc_sk_push_backlog(): send accumulated buffers in socket write queue\n * when socket is in Nagle mode\n+ * @xmitq: receive output queue, or NULL outside receive context\n */\n-static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack)\n+static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack,\n+\t\t\t\t struct sk_buff_head *xmitq)\n {\n \tstruct sk_buff_head *txq = \u0026tsk-\u003esk.sk_write_queue;\n \tstruct sk_buff *skb = skb_peek_tail(txq);\n@@ -1310,6 +1313,12 @@ static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack)\n \t\ttsk-\u003epkt_cnt += skb_queue_len(txq);\n \ttsk-\u003esnt_unacked += tsk-\u003esnd_backlog;\n \ttsk-\u003esnd_backlog = 0;\n+\n+\tif (xmitq \u0026\u0026 in_own_node(net, dnode)) {\n+\t\tskb_queue_splice_tail_init(txq, xmitq);\n+\t\treturn;\n+\t}\n+\n \trc = tipc_node_xmit(net, txq, dnode, tsk-\u003eportid);\n \tif (rc == -ELINKCONG)\n \t\ttsk-\u003econg_link_cnt = 1;\n@@ -1367,7 +1376,7 @@ static void tipc_sk_conn_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb,\n \t\t\tgoto exit;\n \n \t\twas_cong = tsk_conn_cong(tsk);\n-\t\ttipc_sk_push_backlog(tsk, msg_nagle_ack(hdr));\n+\t\ttipc_sk_push_backlog(tsk, msg_nagle_ack(hdr), xmitq);\n \t\ttsk-\u003esnt_unacked -= msg_conn_ack(hdr);\n \t\tif (tsk-\u003epeer_caps \u0026 TIPC_BLOCK_FLOWCTL)\n \t\t\ttsk-\u003esnd_win = msg_adv_win(hdr);\n@@ -2165,7 +2174,7 @@ static void tipc_sk_proto_rcv(struct sock *sk,\n \t\tsmp_wmb();\n \t\ttsk-\u003econg_link_cnt--;\n \t\twakeup = true;\n-\t\ttipc_sk_push_backlog(tsk, false);\n+\t\ttipc_sk_push_backlog(tsk, false, xmitq);\n \t\tbreak;\n \tcase GROUP_PROTOCOL:\n \t\ttipc_group_proto_rcv(grp, \u0026wakeup, hdr, inputq, xmitq);\n@@ -2256,7 +2265,7 @@ static bool tipc_sk_filter_connect(struct tipc_sock *tsk, struct sk_buff *skb,\n \t\treturn false;\n \tcase TIPC_ESTABLISHED:\n \t\tif (!skb_queue_empty(\u0026sk-\u003esk_write_queue))\n-\t\t\ttipc_sk_push_backlog(tsk, false);\n+\t\t\ttipc_sk_push_backlog(tsk, false, xmitq);\n \t\t/* Accept only connection-based messages sent by peer */\n \t\tif (likely(con_msg \u0026\u0026 !err \u0026\u0026 pport == oport \u0026\u0026\n \t\t\t pnode == onode)) {\n"
} |
| 2/1 | 2026/08/12 13:24 | agent | patch-evaluator |
5mModel:best-expensive Args: null Results: {
"EnableConfigs": [
"TIPC",
"TIPC_MEDIA_UDP"
],
"FocusSymbols": [
"tipc_sk_rcv",
"tipc_sk_mcast_rcv"
],
"Reasoning": "The patch modifies the TIPC socket receive and shutdown paths by changing how the socket backlog is pushed. It splices the transmit queue to a provided xmitq instead of transmitting directly when the destination is on the same node. This is a functional change in core TIPC socket logic that affects message transmission and queue management.",
"WorthFuzzing": true
}Instruction: You are an expert Linux kernel maintainer. Your job is to review a provided patch series and determine if it makes functional changes to the kernel that should be fuzzed. IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively use your code access tools to examine the actual source code and confirm any assumptions. Return WorthFuzzing=false if the patch only contains: - Modifications to Documentation/, Kconfig files, or code comments. - Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints. - Changes to numeric constants or macros that do not functionally alter execution flow. - Code paths that are impossible to reach in virtualized environments like GCE or QEMU, even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim). - Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed, ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU. - Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove) that are executed only during PCI hot-unplug or sysfs driver unbind operations. If it modifies reachable core kernel logic, drivers, or architectures, use your code search tools to verify the code can be executed, then return WorthFuzzing=true. When returning WorthFuzzing=true, you MUST ALSO: 1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols. Avoid listing generic hot-path functions to prevent skewed test distributions. Prefer non-static, non-inlined API entrypoint functions over internal static helper functions (which are inlined by the compiler and do not have distinct symbol addresses). 2. Identify any specific CONFIG_ options required to properly test this new/modified feature. Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions. Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed for Kbuild to compile the code statically into vmlinux. List them in the EnableConfigs output array, and DO NOT add a '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: For your convenience, here is the diff of the changes:
commit 4b0645d551d8f4a9d75e7dfc1b1420a76f2c7303
Author: syz-cluster <triage@syzkaller.com>
Date: Wed Aug 12 13:24:32 2026 +0000
syz-cluster: applied patch under review
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index e564341e0216d..33d744dc514f5 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -156,7 +156,8 @@ static int tipc_sk_insert(struct tipc_sock *tsk);
static void tipc_sk_remove(struct tipc_sock *tsk);
static int __tipc_sendstream(struct socket *sock, struct msghdr *m, size_t dsz);
static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz);
-static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack);
+static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack,
+ struct sk_buff_head *xmitq);
static int tipc_wait_for_connect(struct socket *sock, long *timeo_p);
static const struct proto_ops packet_ops;
@@ -560,7 +561,7 @@ static void __tipc_shutdown(struct socket *sock, int error)
!tsk_conn_cong(tsk)));
/* Push out delayed messages if in Nagle mode */
- tipc_sk_push_backlog(tsk, false);
+ tipc_sk_push_backlog(tsk, false, NULL);
/* Remove pending SYN */
__skb_queue_purge(&sk->sk_write_queue);
@@ -1267,8 +1268,10 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
/* tipc_sk_push_backlog(): send accumulated buffers in socket write queue
* when socket is in Nagle mode
+ * @xmitq: receive output queue, or NULL outside receive context
*/
-static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack)
+static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack,
+ struct sk_buff_head *xmitq)
{
struct sk_buff_head *txq = &tsk->sk.sk_write_queue;
struct sk_buff *skb = skb_peek_tail(txq);
@@ -1310,6 +1313,12 @@ static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack)
tsk->pkt_cnt += skb_queue_len(txq);
tsk->snt_unacked += tsk->snd_backlog;
tsk->snd_backlog = 0;
+
+ if (xmitq && in_own_node(net, dnode)) {
+ skb_queue_splice_tail_init(txq, xmitq);
+ return;
+ }
+
rc = tipc_node_xmit(net, txq, dnode, tsk->portid);
if (rc == -ELINKCONG)
tsk->cong_link_cnt = 1;
@@ -1367,7 +1376,7 @@ static void tipc_sk_conn_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb,
goto exit;
was_cong = tsk_conn_cong(tsk);
- tipc_sk_push_backlog(tsk, msg_nagle_ack(hdr));
+ tipc_sk_push_backlog(tsk, msg_nagle_ack(hdr), xmitq);
tsk->snt_unacked -= msg_conn_ack(hdr);
if (tsk->peer_caps & TIPC_BLOCK_FLOWCTL)
tsk->snd_win = msg_adv_win(hdr);
@@ -2165,7 +2174,7 @@ static void tipc_sk_proto_rcv(struct sock *sk,
smp_wmb();
tsk->cong_link_cnt--;
wakeup = true;
- tipc_sk_push_backlog(tsk, false);
+ tipc_sk_push_backlog(tsk, false, xmitq);
break;
case GROUP_PROTOCOL:
tipc_group_proto_rcv(grp, &wakeup, hdr, inputq, xmitq);
@@ -2256,7 +2265,7 @@ static bool tipc_sk_filter_connect(struct tipc_sock *tsk, struct sk_buff *skb,
return false;
case TIPC_ESTABLISHED:
if (!skb_queue_empty(&sk->sk_write_queue))
- tipc_sk_push_backlog(tsk, false);
+ tipc_sk_push_backlog(tsk, false, xmitq);
/* Accept only connection-based messages sent by peer */
if (likely(con_msg && !err && pport == oport &&
pnode == onode)) {
|
| 3/2 | 2026/08/12 13:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 3101 output: 28 thoughts: 183 Thoughts: **Analyzing the TIPC Socket Modification** Okay, so this patch is digging into `net/tipc/socket.c`, specifically changing how TIPC sockets handle backlog. The most significant change I see is the added `struct sk_buff_head *xmitq` parameter to `tipc_sk_push_backlog`. That's a clear signal of an architectural shift. I'm noting that the existing call sites are being updated to pass in this new `xmitq`, or `NULL` in the `__tipc_shutdown` case. The core of the change is in `tipc_sk_push_backlog` itself: this new check for `xmitq` and `in_own_node` suggests a performance optimization, or perhaps a change in how local and remote transmissions are managed. If both conditions are met – a transmit queue is provided (`xmitq`) and we're dealing with the same node – it splices the transmit queue (`txq`) onto the provided `xmitq` and returns. No further processing is performed for local transmissions. This seems like a functional improvement to TIPC socket handling, likely aimed at improving efficiency. This could be aimed at optimizing performance or addressing a potential race condition in how TIPC sockets handle transmission backlogs. Time to delve into the Kconfig for TIPC and understand the bigger picture of this networking protocol. I need to understand if this interacts with any other features or configurations. |
| 4/2 | 2026/08/12 13:24 | tool | grepper |
0mArgs:{
"Expression": "config TIPC",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/Kconfig-5-\nnet/tipc/Kconfig:6:menuconfig TIPC\nnet/tipc/Kconfig-7-\ttristate \"The TIPC Protocol\"\n--\nnet/tipc/Kconfig-23-\nnet/tipc/Kconfig:24:config TIPC_MEDIA_IB\nnet/tipc/Kconfig-25-\tbool \"InfiniBand media type support\"\n--\nnet/tipc/Kconfig-29-\t IP-over-InfiniBand devices.\nnet/tipc/Kconfig:30:config TIPC_MEDIA_UDP\nnet/tipc/Kconfig-31-\tbool \"IP/UDP media type support\"\n--\nnet/tipc/Kconfig-37-\nnet/tipc/Kconfig:38:config TIPC_CRYPTO\nnet/tipc/Kconfig-39-\tbool \"TIPC encryption support\"\n--\nnet/tipc/Kconfig-52-\nnet/tipc/Kconfig:53:config TIPC_DIAG\nnet/tipc/Kconfig-54-\ttristate \"TIPC: socket monitoring interface\"\n"
} |
| 5/2 | 2026/08/12 13:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 3908 output: 36 thoughts: 103 Thoughts: **Analyzing the TIPC Configuration and Backlog Function** Okay, so the configuration in question here is `TIPC`. My attention is drawn to the function `tipc_sk_push_backlog`, and I need to understand its role. Ah, right, I see it's declared `static`. That immediately limits my scope of investigation. I need to trace the call paths to figure out how it's used within this specific implementation. Looking at the callers, I've got `__tipc_shutdown`, `tipc_sk_conn_proto_rcv`, `tipc_sk_proto_rcv`, and `tipc_sk_filter_connect`. Now, because the function is static, I can't just look outside the file the function is declared in. I'm going to quickly review these callers, especially the non-static ones (or their callers) to understand the data flow and determine the implications of any changes within `tipc_sk_push_backlog`. I need to figure out the context of each call to fully grasp the function's responsibility and the potential impact of modifications. |
| 6/2 | 2026/08/12 13:24 | tool | grepper |
0mArgs:{
"Expression": "tipc_sk_conn_proto_rcv",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/socket.c=1273=static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack,\n--\nnet/tipc/socket.c-1327-/**\nnet/tipc/socket.c:1328: * tipc_sk_conn_proto_rcv - receive a connection mng protocol message\nnet/tipc/socket.c-1329- * @tsk: receiving socket\n--\nnet/tipc/socket.c-1333- */\nnet/tipc/socket.c:1334:static void tipc_sk_conn_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb,\nnet/tipc/socket.c-1335-\t\t\t\t struct sk_buff_head *inputq,\n--\nnet/tipc/socket.c=2157=static void tipc_sk_proto_rcv(struct sock *sk,\n--\nnet/tipc/socket.c-2168-\tcase CONN_MANAGER:\nnet/tipc/socket.c:2169:\t\ttipc_sk_conn_proto_rcv(tsk, skb, inputq, xmitq);\nnet/tipc/socket.c-2170-\t\treturn;\n"
} |
| 7/2 | 2026/08/12 13:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 4617 output: 34 thoughts: 21 Thoughts: Here's a summary of my thought process: **Caller Analysis for a Static Function** Okay, so `tipc_sk_proto_rcv` is a static function. That means it's only visible within its compilation unit, which makes debugging a little trickier, but also focuses my search. My immediate thought is, "Let's find out who's calling it". I need to understand its role within the larger system. I'll need to use my tools to locate all the call sites to get a grasp of its purpose and how it fits into the data flow. Understanding the context of the callers will provide valuable insights into what this function *does*. |
| 8/2 | 2026/08/12 13:24 | tool | grepper |
0mArgs:{
"Expression": "tipc_sk_proto_rcv",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/socket.c=403=static int tipc_sk_sock_err(struct socket *sock, long *timeout)\n--\nnet/tipc/socket.c-431-\twhile ((rc_ = !(condition_))) {\t\t\t\t\t \\\nnet/tipc/socket.c:432:\t\t/* coupled with smp_wmb() in tipc_sk_proto_rcv() */ \\\nnet/tipc/socket.c-433-\t\tsmp_rmb(); \\\n--\nnet/tipc/socket.c=2152=static void tipc_sock_destruct(struct sock *sk)\n--\nnet/tipc/socket.c-2156-\nnet/tipc/socket.c:2157:static void tipc_sk_proto_rcv(struct sock *sk,\nnet/tipc/socket.c-2158-\t\t\t struct sk_buff_head *inputq,\n--\nnet/tipc/socket.c=2347=static void tipc_sk_filter_rcv(struct sock *sk, struct sk_buff *skb,\n--\nnet/tipc/socket.c-2364-\tif (unlikely(!msg_isdata(hdr)))\nnet/tipc/socket.c:2365:\t\ttipc_sk_proto_rcv(sk, \u0026inputq, xmitq);\nnet/tipc/socket.c-2366-\n"
} |
| 9/2 | 2026/08/12 13:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 5182 output: 34 thoughts: 21 Thoughts: Here's a summary of my thought process: **Caller Discovery for a Static Function** Okay, so `tipc_sk_filter_rcv` is a static function. That means it's only visible within its compilation unit, which makes figuring out where it's *actually* used a bit trickier. The standard tools won't just immediately point me to every call site across the whole codebase. My immediate thought is, let's track down all the calls to it. Knowing the callers is *crucial* for understanding its purpose, potential impact, and dependencies within this TIPC kernel module. Understanding who's calling it is the first step. |
| 10/2 | 2026/08/12 13:24 | tool | grepper |
0mArgs:{
"Expression": "tipc_sk_filter_rcv",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/socket.c=2319=static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *skb)\n--\nnet/tipc/socket.c-2336-/**\nnet/tipc/socket.c:2337: * tipc_sk_filter_rcv - validate incoming message\nnet/tipc/socket.c-2338- * @sk: socket\n--\nnet/tipc/socket.c-2346- */\nnet/tipc/socket.c:2347:static void tipc_sk_filter_rcv(struct sock *sk, struct sk_buff *skb,\nnet/tipc/socket.c-2348-\t\t\t struct sk_buff_head *xmitq)\n--\nnet/tipc/socket.c-2358-\nnet/tipc/socket.c:2359:\ttrace_tipc_sk_filter_rcv(sk, skb, TIPC_DUMP_ALL, \" \");\nnet/tipc/socket.c-2360-\tTIPC_SKB_CB(skb)-\u003ebytes_read = 0;\n--\nnet/tipc/socket.c=2412=static int tipc_sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)\n--\nnet/tipc/socket.c-2419-\nnet/tipc/socket.c:2420:\ttipc_sk_filter_rcv(sk, skb, \u0026xmitq);\nnet/tipc/socket.c-2421-\tadded = sk_rmem_alloc_get(sk) - before;\n--\nnet/tipc/socket.c=2439=static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk,\n--\nnet/tipc/socket.c-2457-\t\tif (!sock_owned_by_user(sk)) {\nnet/tipc/socket.c:2458:\t\t\ttipc_sk_filter_rcv(sk, skb, xmitq);\nnet/tipc/socket.c-2459-\t\t\tcontinue;\n--\nnet/tipc/trace.h=227=DEFINE_SK_EVENT_FILTER(tipc_sk_poll);\nnet/tipc/trace.h:228:DEFINE_SK_EVENT_FILTER(tipc_sk_filter_rcv);\nnet/tipc/trace.h-229-DEFINE_SK_EVENT_FILTER(tipc_sk_advance_rx);\n"
} |
| 11/2 | 2026/08/12 13:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 6020 output: 31 thoughts: 31 Thoughts: Here's my take on the thought process, as if it were my own: **Investigating `tipc_sk_enqueue` and `tipc_sk_backlog_rcv`** Okay, so I've spotted `tipc_sk_enqueue` and `tipc_sk_backlog_rcv` – and it's flagged that they're `static`. Immediately, that sparks my curiosity. Static functions are, by definition, limited in their scope. They're internal to their compilation unit, which means their usage should be contained. This makes them good candidates for deeper analysis, and it should simplify tracking where they are used. My immediate next step is clear: I need to quickly identify all the points in the code where these two functions are actually called. Understanding who's invoking them is fundamental to understanding their purpose and impact within the larger TIPC subsystem. Let's trace their callers and see where they fit in. I'll need to use my usual methods, whether that's `grep`, `cscope`, `clangd` or something similar, and make sure to understand the surrounding context of the calls. |
| 12/2 | 2026/08/12 13:25 | tool | grepper |
0mArgs:{
"Expression": "tipc_sk_enqueue",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/socket.c=2412=static int tipc_sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)\n--\nnet/tipc/socket.c-2429-/**\nnet/tipc/socket.c:2430: * tipc_sk_enqueue - extract all buffers with destination 'dport' from\nnet/tipc/socket.c-2431- * inputq and try adding them to socket or backlog queue\n--\nnet/tipc/socket.c-2438- */\nnet/tipc/socket.c:2439:static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk,\nnet/tipc/socket.c-2440-\t\t\t u32 dport, struct sk_buff_head *xmitq)\n--\nnet/tipc/socket.c=2493=void tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq)\n--\nnet/tipc/socket.c-2509-\t\t\tif (likely(spin_trylock_bh(\u0026sk-\u003esk_lock.slock))) {\nnet/tipc/socket.c:2510:\t\t\t\ttipc_sk_enqueue(inputq, sk, dport, \u0026xmitq);\nnet/tipc/socket.c-2511-\t\t\t\tspin_unlock_bh(\u0026sk-\u003esk_lock.slock);\n"
} |
| 13/2 | 2026/08/12 13:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 6694 output: 35 thoughts: 41 Thoughts: Okay, here's my interpretation of those thoughts, tailored for an expert audience, presented in the first person: **Investigating the TIPC Socket Receive Path** Right, `tipc_sk_rcv` isn't static, which immediately flags it as a function that's either exported for use elsewhere or, more likely, is called from another part of the TIPC subsystem. That's key. We know the function isn't isolated. Now, the question is, where is it called from? Let's trace this back. Given its name, it's likely involved in the receive path. `tipc_sk_backlog_rcv` looks like the logical next point to investigate. It could be part of a backlog mechanism, potentially feeding into `tipc_sk_rcv`. This looks like a good place to start my investigation. |
| 14/2 | 2026/08/12 13:25 | tool | grepper |
0mArgs:{
"Expression": "tipc_sk_backlog_rcv",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/socket.c=110=struct tipc_sock {\n--\nnet/tipc/socket.c-144-\nnet/tipc/socket.c:145:static int tipc_sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);\nnet/tipc/socket.c-146-static void tipc_data_ready(struct sock *sk);\n--\nnet/tipc/socket.c=460=static int tipc_sk_create(struct net *net, struct socket *sock,\n--\nnet/tipc/socket.c-518-\tsk-\u003esk_shutdown = 0;\nnet/tipc/socket.c:519:\tsk-\u003esk_backlog_rcv = tipc_sk_backlog_rcv;\nnet/tipc/socket.c-520-\tsk-\u003esk_rcvbuf = READ_ONCE(sysctl_tipc_rmem[1]);\n--\nnet/tipc/socket.c=2347=static void tipc_sk_filter_rcv(struct sock *sk, struct sk_buff *skb,\n--\nnet/tipc/socket.c-2405-/**\nnet/tipc/socket.c:2406: * tipc_sk_backlog_rcv - handle incoming message from backlog queue\nnet/tipc/socket.c-2407- * @sk: socket\n--\nnet/tipc/socket.c-2411- */\nnet/tipc/socket.c:2412:static int tipc_sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)\nnet/tipc/socket.c-2413-{\n"
} |
| 15/2 | 2026/08/12 13:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 7392 output: 32 thoughts: 356 Thoughts: **My Assessment of the TIPC Socket Patch** Okay, so I've been looking over this TIPC socket patch, and here's my take. The crucial point here is the connection between `tipc_sk_backlog_rcv` and `sk->sk_backlog_rcv` within `tipc_sk_create`. That tells me we're looking at functions exposed via standard socket operations. This patch makes a functional change to `tipc_sk_push_backlog`, the function called to process incoming messages. The update introduces the `xmitq` variable and conditionally splices the `txq` to `xmitq` if the destination node is the same. This likely affects how Nagle's algorithm interacts with backlog processing. This is core socket logic that has changed, so fuzzing this is *definitely* worthwhile. Now, let's nail down some specific functions to target for fuzzing. `tipc_sk_rcv` is an obvious choice since it's directly related to receiving data. `tipc_sk_create` is the socket creation function, so we need to hit that for test setup. Considering the changes, I should check the functions that interact with the patch's changes such as `tipc_sendmsg` and `tipc_sendstream`. The patch touches `__tipc_shutdown`, which calls `tipc_sk_push_backlog`. `tipc_sk_conn_proto_rcv`, `tipc_sk_proto_rcv`, and `tipc_sk_filter_connect` are also potentially involved. Let's see what calls these functions. `tipc_sk_rcv` is non-static, which is good; it's likely called from outside. Also, `tipc_sk_mcast_rcv` is non-static and probably can be used too. `tipc_sendmsg` and `tipc_sendstream` are standard socket operations. Let's start with a deep dive into `tipc_sk_rcv` and figure out how to fuzz it effectively. |
| 16/2 | 2026/08/12 13:25 | tool | grepper |
0mArgs:{
"Expression": "tipc_sk_rcv",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/bcast.c=436=int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb)\n--\nnet/tipc/bcast.c-460-\tif (!skb_queue_empty(inputq))\nnet/tipc/bcast.c:461:\t\ttipc_sk_rcv(net, inputq);\nnet/tipc/bcast.c-462-\n--\nnet/tipc/bcast.c=470=void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l,\n--\nnet/tipc/bcast.c-490-\tif (!skb_queue_empty(inputq))\nnet/tipc/bcast.c:491:\t\ttipc_sk_rcv(net, inputq);\nnet/tipc/bcast.c-492-}\n--\nnet/tipc/bcast.c=498=int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,\n--\nnet/tipc/bcast.c-532-\tif (!skb_queue_empty(inputq))\nnet/tipc/bcast.c:533:\t\ttipc_sk_rcv(net, inputq);\nnet/tipc/bcast.c-534-\treturn rc;\n--\nnet/tipc/bcast.c=557=void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)\n--\nnet/tipc/bcast.c-574-\tif (!skb_queue_empty(inputq))\nnet/tipc/bcast.c:575:\t\ttipc_sk_rcv(net, inputq);\nnet/tipc/bcast.c-576-}\n--\nnet/tipc/node.c=1062=static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)\n--\nnet/tipc/node.c-1093-\t\ttipc_bearer_xmit(n-\u003enet, bearer_id, \u0026xmitq, maddr, n);\nnet/tipc/node.c:1094:\ttipc_sk_rcv(n-\u003enet, \u0026le-\u003einputq);\nnet/tipc/node.c-1095-}\n--\nnet/tipc/node.c=1627=static void tipc_lxc_xmit(struct net *peer_net, struct sk_buff_head *list)\n--\nnet/tipc/node.c-1640-\t\t\tspin_lock_init(\u0026list-\u003elock);\nnet/tipc/node.c:1641:\t\t\ttipc_sk_rcv(peer_net, list);\nnet/tipc/node.c-1642-\t\t\treturn;\n--\nnet/tipc/node.c-1665-\t\tspin_lock_init(\u0026list-\u003elock);\nnet/tipc/node.c:1666:\t\ttipc_sk_rcv(peer_net, list);\nnet/tipc/node.c-1667-\t\treturn;\n--\nnet/tipc/node.c=1687=int tipc_node_xmit(struct net *net, struct sk_buff_head *list,\n--\nnet/tipc/node.c-1700-\t\tspin_lock_init(\u0026list-\u003elock);\nnet/tipc/node.c:1701:\t\ttipc_sk_rcv(net, list);\nnet/tipc/node.c-1702-\t\treturn 0;\n--\nnet/tipc/node.c=2086=void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)\n--\nnet/tipc/node.c-2202-\tif (!skb_queue_empty(\u0026le-\u003einputq))\nnet/tipc/node.c:2203:\t\ttipc_sk_rcv(net, \u0026le-\u003einputq);\nnet/tipc/node.c-2204-\n--\nnet/tipc/socket.c=1192=void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,\n--\nnet/tipc/socket.c-1265-\t}\nnet/tipc/socket.c:1266:\ttipc_sk_rcv(net, inputq);\nnet/tipc/socket.c-1267-}\n--\nnet/tipc/socket.c=2439=static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk,\n--\nnet/tipc/socket.c-2486-/**\nnet/tipc/socket.c:2487: * tipc_sk_rcv - handle a chain of incoming buffers\nnet/tipc/socket.c-2488- * @net: the associated network namespace\n--\nnet/tipc/socket.c-2492- */\nnet/tipc/socket.c:2493:void tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq)\nnet/tipc/socket.c-2494-{\n--\nnet/tipc/socket.h=55=void tipc_socket_stop(void);\nnet/tipc/socket.h:56:void tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq);\nnet/tipc/socket.h-57-void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,\n--\nnet/tipc/topsrv.c=614=static void tipc_topsrv_kern_evt(struct net *net, struct tipc_event *evt)\n--\nnet/tipc/topsrv.c-629-\ttipc_loopback_trace(net, \u0026evtq);\nnet/tipc/topsrv.c:630:\ttipc_sk_rcv(net, \u0026evtq);\nnet/tipc/topsrv.c-631-}\n"
} |
| 17/2 | 2026/08/12 13:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 9803 output: 30 thoughts: 253 Thoughts: **Analyzing the TIPC Socket Receive Path** Okay, let's break this down. My initial focus is on the core of TIPC socket message handling. `tipc_sk_rcv` is the main function for receiving messages into sockets, and `tipc_sk_mcast_rcv` handles multicast specifically. Transmission happens via `tipc_node_xmit`. The patch modifies `tipc_sk_push_backlog`, which immediately tells me this is a key area. Now, *who* calls `tipc_sk_push_backlog`? The text lists a number of callers: `__tipc_shutdown`, `tipc_sk_conn_proto_rcv`, `tipc_sk_proto_rcv`, and `tipc_sk_filter_connect`. Hmm, these are all interesting because they're *directly* involved in socket receive or shutdown operations. It's a clear flow: `tipc_sk_rcv` calls `tipc_sk_enqueue`, which leads to `tipc_sk_filter_rcv`, which then dispatches to `tipc_sk_proto_rcv` or `tipc_sk_conn_proto_rcv` or `tipc_sk_filter_connect`. The other call path comes from `__tipc_shutdown`. This clearly means that `tipc_sk_rcv` and the shutdown sequence are important entry points for understanding the patch's effects. Excellent, `tipc_sk_rcv` is a good focus. And of course, the shutdown is relevant as well. Wait a second. `__tipc_shutdown` is a static function. That means it can't be called from outside the source file it's declared in. So, to get the complete picture of shutdown behaviour, I need to figure out which non-static function wraps `__tipc_shutdown`. It is likely that the patch is affecting the entry point function of the shutdown behaviour. Time to go hunting! |
| 18/2 | 2026/08/12 13:25 | tool | grepper |
0mArgs:{
"Expression": "__tipc_shutdown",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/socket.c=542=static void tipc_sk_callback(struct rcu_head *head)\n--\nnet/tipc/socket.c-549-/* Caller should hold socket lock for the socket. */\nnet/tipc/socket.c:550:static void __tipc_shutdown(struct socket *sock, int error)\nnet/tipc/socket.c-551-{\n--\nnet/tipc/socket.c=626=static int tipc_release(struct socket *sock)\n--\nnet/tipc/socket.c-641-\ttrace_tipc_sk_release(sk, NULL, TIPC_DUMP_ALL, \" \");\nnet/tipc/socket.c:642:\t__tipc_shutdown(sock, TIPC_ERR_NO_PORT);\nnet/tipc/socket.c-643-\tsk-\u003esk_shutdown = SHUTDOWN_MASK;\n--\nnet/tipc/socket.c=2809=static int tipc_shutdown(struct socket *sock, int how)\n--\nnet/tipc/socket.c-2819-\ttrace_tipc_sk_shutdown(sk, NULL, TIPC_DUMP_ALL, \" \");\nnet/tipc/socket.c:2820:\t__tipc_shutdown(sock, TIPC_CONN_SHUTDOWN);\nnet/tipc/socket.c-2821-\tsk-\u003esk_shutdown = SHUTDOWN_MASK;\n"
} |
| 19/2 | 2026/08/12 13:25 | llm | patch-evaluator |
3mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 10893 output: 29 thoughts: 35 Thoughts: Okay, here's my take on those thoughts, framed as an expert's inner monologue: **Checking Socket Operations in TIPC** Alright, let's drill down into these TIPC socket operations. Specifically, I need to make sure `tipc_release` and `tipc_shutdown` are correctly wired up. I know they're the non-static ones – the ones dealing with the socket instance itself rather than just the underlying protocol. My immediate check has to be the `proto_ops` structure. That's where all the fundamental socket operations are defined. I have to verify that these two functions, `tipc_release` and `tipc_shutdown`, are actually assigned within that structure. That is the critical place to ensure proper socket management within the TIPC framework. If they are not in the `proto_ops` structure, we're in trouble. |
| 20/2 | 2026/08/12 13:29 | tool | grepper |
0mArgs:{
"Expression": "tipc_shutdown",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/socket.c=542=static void tipc_sk_callback(struct rcu_head *head)\n--\nnet/tipc/socket.c-549-/* Caller should hold socket lock for the socket. */\nnet/tipc/socket.c:550:static void __tipc_shutdown(struct socket *sock, int error)\nnet/tipc/socket.c-551-{\n--\nnet/tipc/socket.c=626=static int tipc_release(struct socket *sock)\n--\nnet/tipc/socket.c-641-\ttrace_tipc_sk_release(sk, NULL, TIPC_DUMP_ALL, \" \");\nnet/tipc/socket.c:642:\t__tipc_shutdown(sock, TIPC_ERR_NO_PORT);\nnet/tipc/socket.c-643-\tsk-\u003esk_shutdown = SHUTDOWN_MASK;\n--\nnet/tipc/socket.c=2729=static int tipc_accept(struct socket *sock, struct socket *new_sock,\n--\nnet/tipc/socket.c-2800-/**\nnet/tipc/socket.c:2801: * tipc_shutdown - shutdown socket connection\nnet/tipc/socket.c-2802- * @sock: socket structure\n--\nnet/tipc/socket.c-2808- */\nnet/tipc/socket.c:2809:static int tipc_shutdown(struct socket *sock, int how)\nnet/tipc/socket.c-2810-{\n--\nnet/tipc/socket.c-2819-\ttrace_tipc_sk_shutdown(sk, NULL, TIPC_DUMP_ALL, \" \");\nnet/tipc/socket.c:2820:\t__tipc_shutdown(sock, TIPC_CONN_SHUTDOWN);\nnet/tipc/socket.c-2821-\tsk-\u003esk_shutdown = SHUTDOWN_MASK;\n--\nnet/tipc/socket.c=3367=static const struct proto_ops msg_ops = {\n--\nnet/tipc/socket.c-3378-\t.listen\t\t= sock_no_listen,\nnet/tipc/socket.c:3379:\t.shutdown\t= tipc_shutdown,\nnet/tipc/socket.c-3380-\t.setsockopt\t= tipc_setsockopt,\n--\nnet/tipc/socket.c=3387=static const struct proto_ops packet_ops = {\n--\nnet/tipc/socket.c-3398-\t.listen\t\t= tipc_listen,\nnet/tipc/socket.c:3399:\t.shutdown\t= tipc_shutdown,\nnet/tipc/socket.c-3400-\t.setsockopt\t= tipc_setsockopt,\n--\nnet/tipc/socket.c=3407=static const struct proto_ops stream_ops = {\n--\nnet/tipc/socket.c-3418-\t.listen\t\t= tipc_listen,\nnet/tipc/socket.c:3419:\t.shutdown\t= tipc_shutdown,\nnet/tipc/socket.c-3420-\t.setsockopt\t= tipc_setsockopt,\n"
} |
| 21/2 | 2026/08/12 13:29 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 11976 output: 28 thoughts: 487 Thoughts: **Analyzing TIPC Socket Operations** Okay, so I'm digging into TIPC socket operations, trying to identify good entry points for something... I initially thought `tipc_shutdown` and `tipc_release` might be decent, but they're static socket operations. That's a flag. While it's unlikely, being static means they *could* be inlined. Socket operations are *usually* not inlined because their addresses are used for `proto_ops`, but it's still something to consider. Then I checked `tipc_sk_rcv` – and it's global, exported, a solid candidate! Let's verify... yes, global. Bingo. Any other global functions to consider? I quickly found `tipc_node_xmit` and `tipc_sk_mcast_rcv`. So, `tipc_sk_rcv`, `tipc_node_xmit`, and `tipc_sk_mcast_rcv` are potential *FocusSymbols*. But let's think a bit more deeply about the call path. Wait, `tipc_sk_push_backlog` is called from `tipc_sk_rcv` (via `tipc_sk_filter_rcv` -> `tipc_sk_proto_rcv` etc.). Ah, that settles it! `tipc_sk_rcv` looks perfect because it's global and ties into the receive path. Even though `tipc_shutdown` and `tipc_release` are static, they should be address-taken, so they won't be inlined. But given the prompt "Prefer non-static, non-inlined API entrypoint functions over internal static helper functions", `tipc_sk_rcv` is the better choice. What about other send operations? Are `tipc_sendmsg` and `tipc_sendstream` promising? Those are static too. I quickly checked whether `tipc_sk_push_backlog` is called from `sendmsg`, but no, those are all receive and shutdown path, like I expected. Okay, so `tipc_sk_rcv` and `tipc_shutdown` (or maybe `tipc_release`, although they are equivalent) are the cleanest entry points. Finally, just to be thorough, I should look at the Kconfig and see how `TIPC` is defined and what it depends on. Let's make sure there aren't any gotchas in the build configuration. |
| 22/2 | 2026/08/12 13:29 | tool | grepper |
0mArgs:{
"Expression": "config TIPC",
"PathPrefix": "net/tipc/"
}Results: {
"Output": "net/tipc/Kconfig-5-\nnet/tipc/Kconfig:6:menuconfig TIPC\nnet/tipc/Kconfig-7-\ttristate \"The TIPC Protocol\"\n--\nnet/tipc/Kconfig-23-\nnet/tipc/Kconfig:24:config TIPC_MEDIA_IB\nnet/tipc/Kconfig-25-\tbool \"InfiniBand media type support\"\n--\nnet/tipc/Kconfig-29-\t IP-over-InfiniBand devices.\nnet/tipc/Kconfig:30:config TIPC_MEDIA_UDP\nnet/tipc/Kconfig-31-\tbool \"IP/UDP media type support\"\n--\nnet/tipc/Kconfig-37-\nnet/tipc/Kconfig:38:config TIPC_CRYPTO\nnet/tipc/Kconfig-39-\tbool \"TIPC encryption support\"\n--\nnet/tipc/Kconfig-52-\nnet/tipc/Kconfig:53:config TIPC_DIAG\nnet/tipc/Kconfig-54-\ttristate \"TIPC: socket monitoring interface\"\n"
} |
| 23/2 | 2026/08/12 13:29 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 13320 output: 33 thoughts: 17 Thoughts: Here's my thought process, as if I were considering this myself: **Examining the TIPC Configuration Dependencies** Okay, so I need to get a handle on the dependencies for the TIPC (Transparent Inter-Process Communication) configuration. My immediate instinct is to dive into the `net/tipc/Kconfig` file. That's the standard place for this kind of information, so let's start there. I'll need to understand what other kernel features or options need to be enabled or disabled for TIPC to work correctly, or what other options are required to enable certain TIPC features. Gotta make sure I get a good understanding of that configuration space. |
| 24/2 | 2026/08/12 13:29 | tool | read-file |
0mArgs:{
"File": "net/tipc/Kconfig",
"FirstLine": 1,
"LineCount": 20
}Results: {
"Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0-only\n 2:\t#\n 3:\t# TIPC configuration\n 4:\t#\n 5:\t\n 6:\tmenuconfig TIPC\n 7:\t\ttristate \"The TIPC Protocol\"\n 8:\t\tdepends on INET\n 9:\t\thelp\n 10:\t\t The Transparent Inter Process Communication (TIPC) protocol is\n 11:\t\t specially designed for intra cluster communication. This protocol\n 12:\t\t originates from Ericsson where it has been used in carrier grade\n 13:\t\t cluster applications for many years.\n 14:\t\n 15:\t\t For more information about TIPC, see http://tipc.sourceforge.net.\n 16:\t\n 17:\t\t This protocol support is also available as a module ( = code which\n 18:\t\t can be inserted in and removed from the running kernel whenever you\n 19:\t\t want). The module will be called tipc. If you want to compile it\n 20:\t\t as a module, say M here and read \u003cfile:Documentation/kbuild/modules.rst\u003e.\n"
} |
| 25/2 | 2026/08/12 13:29 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 13799 output: 130 thoughts: 406 Thoughts: **My Analysis of This TIPC Patch** Okay, so this patch fundamentally touches `TIPC`, which I know depends on `INET`. Therefore, enabling `TIPC` is the key configuration to get started. My immediate thought is to double-check the entry points this change affects, specifically if `tipc_sk_rcv` is the only non-static one. But, no, `tipc_sk_mcast_rcv` is also exposed. I'll add both `tipc_sk_rcv` and `tipc_sk_mcast_rcv` to `FocusSymbols` to target them specifically. Now, looking deeper, the patch alters `tipc_sk_push_backlog`. It's splicing `txq` to `xmitq` when `xmitq` is provided and the destination is on the same node. This is a clever optimization, bypassing the normal `tipc_node_xmit` path and directly queueing packets to `xmitq`, which the caller then handles. This is either a performance win, a lock issue fix or maybe just a functional batching change. This needs to be fuzzed! Alright, time to distill this information into the required parameters. We're definitely tagging this as `WorthFuzzing=true`. `FocusSymbols` includes `tipc_sk_rcv` and `tipc_sk_mcast_rcv`. `EnableConfigs` will start with `TIPC`. The core reasoning is that the patch fundamentally changes the TIPC socket receive and shutdown paths by altering the backlog pushing mechanism. It splices the transmit queue to a provided xmitq rather than transmitting directly when the destination is on the same node. This is a functional change in core TIPC socket logic. Let's quickly check for any other relevant configs. Ah, `TIPC_MEDIA_UDP`. While `TIPC` is sufficient to enable the core, `TIPC_MEDIA_UDP` would be useful for fuzzing TIPC over UDP, which syzkaller often targets. So, just to be thorough and because it can't hurt, I'll include both `TIPC` and `TIPC_MEDIA_UDP` in `EnableConfigs`. |
| 26/2 | 2026/08/12 13:30 | tool | set-results |
0mArgs:{
"EnableConfigs": [
"TIPC",
"TIPC_MEDIA_UDP"
],
"FocusSymbols": [
"tipc_sk_rcv",
"tipc_sk_mcast_rcv"
],
"Reasoning": "The patch modifies the TIPC socket receive and shutdown paths by changing how the socket backlog is pushed. It splices the transmit queue to a provided xmitq instead of transmitting directly when the destination is on the same node. This is a functional change in core TIPC socket logic that affects message transmission and queue management.",
"WorthFuzzing": true
}Results: {
"EnableConfigs": [
"TIPC",
"TIPC_MEDIA_UDP"
],
"FocusSymbols": [
"tipc_sk_rcv",
"tipc_sk_mcast_rcv"
],
"Reasoning": "The patch modifies the TIPC socket receive and shutdown paths by changing how the socket backlog is pushed. It splices the transmit queue to a provided xmitq instead of transmitting directly when the destination is on the same node. This is a functional change in core TIPC socket logic that affects message transmission and queue management.",
"WorthFuzzing": true
} |
| 27/1 | 2026/08/12 13:30 | action | If |
0mArgs:{
"WorthFuzzing": true
}Results: null |
| 28/2 | 2026/08/12 13:30 | agent | kmsan-evaluator |
0mModel:best-expensive Args: null Results: {
"KMSANReasoning": "The patch modifies the `tipc_sk_push_backlog` function to accept an additional `xmitq` argument, allowing it to splice the socket's write queue directly into the transmit queue when sending to the same node, rather than calling `tipc_node_xmit`. This is a control flow and queue management change. It does not introduce any new data structures, allocations, or copying of data to user space. Any potential bugs introduced by this change would be related to queue management (e.g., use-after-free, NULL pointer dereferences, or memory leaks), which are effectively detected by KASAN and standard kernel debugging tools. There is no risk of uninitialized memory usage or info-leaks that would require KMSAN.",
"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: For your convenience, here is the diff of the changes:
commit 4b0645d551d8f4a9d75e7dfc1b1420a76f2c7303
Author: syz-cluster <triage@syzkaller.com>
Date: Wed Aug 12 13:24:32 2026 +0000
syz-cluster: applied patch under review
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index e564341e0216d..33d744dc514f5 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -156,7 +156,8 @@ static int tipc_sk_insert(struct tipc_sock *tsk);
static void tipc_sk_remove(struct tipc_sock *tsk);
static int __tipc_sendstream(struct socket *sock, struct msghdr *m, size_t dsz);
static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz);
-static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack);
+static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack,
+ struct sk_buff_head *xmitq);
static int tipc_wait_for_connect(struct socket *sock, long *timeo_p);
static const struct proto_ops packet_ops;
@@ -560,7 +561,7 @@ static void __tipc_shutdown(struct socket *sock, int error)
!tsk_conn_cong(tsk)));
/* Push out delayed messages if in Nagle mode */
- tipc_sk_push_backlog(tsk, false);
+ tipc_sk_push_backlog(tsk, false, NULL);
/* Remove pending SYN */
__skb_queue_purge(&sk->sk_write_queue);
@@ -1267,8 +1268,10 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
/* tipc_sk_push_backlog(): send accumulated buffers in socket write queue
* when socket is in Nagle mode
+ * @xmitq: receive output queue, or NULL outside receive context
*/
-static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack)
+static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack,
+ struct sk_buff_head *xmitq)
{
struct sk_buff_head *txq = &tsk->sk.sk_write_queue;
struct sk_buff *skb = skb_peek_tail(txq);
@@ -1310,6 +1313,12 @@ static void tipc_sk_push_backlog(struct tipc_sock *tsk, bool nagle_ack)
tsk->pkt_cnt += skb_queue_len(txq);
tsk->snt_unacked += tsk->snd_backlog;
tsk->snd_backlog = 0;
+
+ if (xmitq && in_own_node(net, dnode)) {
+ skb_queue_splice_tail_init(txq, xmitq);
+ return;
+ }
+
rc = tipc_node_xmit(net, txq, dnode, tsk->portid);
if (rc == -ELINKCONG)
tsk->cong_link_cnt = 1;
@@ -1367,7 +1376,7 @@ static void tipc_sk_conn_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb,
goto exit;
was_cong = tsk_conn_cong(tsk);
- tipc_sk_push_backlog(tsk, msg_nagle_ack(hdr));
+ tipc_sk_push_backlog(tsk, msg_nagle_ack(hdr), xmitq);
tsk->snt_unacked -= msg_conn_ack(hdr);
if (tsk->peer_caps & TIPC_BLOCK_FLOWCTL)
tsk->snd_win = msg_adv_win(hdr);
@@ -2165,7 +2174,7 @@ static void tipc_sk_proto_rcv(struct sock *sk,
smp_wmb();
tsk->cong_link_cnt--;
wakeup = true;
- tipc_sk_push_backlog(tsk, false);
+ tipc_sk_push_backlog(tsk, false, xmitq);
break;
case GROUP_PROTOCOL:
tipc_group_proto_rcv(grp, &wakeup, hdr, inputq, xmitq);
@@ -2256,7 +2265,7 @@ static bool tipc_sk_filter_connect(struct tipc_sock *tsk, struct sk_buff *skb,
return false;
case TIPC_ESTABLISHED:
if (!skb_queue_empty(&sk->sk_write_queue))
- tipc_sk_push_backlog(tsk, false);
+ tipc_sk_push_backlog(tsk, false, xmitq);
/* Accept only connection-based messages sent by peer */
if (likely(con_msg && !err && pport == oport &&
pnode == onode)) {
|
| 29/3 | 2026/08/12 13:30 | llm | kmsan-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 3098 output: 183 thoughts: 388 Thoughts: **Analyzing the TIPC Socket Modification**
Okay, let's break this down. The patch changes `tipc_sk_push_backlog` within `net/tipc/socket.c` to include an additional argument, `xmitq`, a pointer to a `struct sk_buff_head`. The core of the change lies in conditionally splicing `txq` into `xmitq` if `xmitq` is provided and the destination node matches the local node. The intent here is clear: to bypass a call to `tipc_node_xmit` when receiving on the local node, opting instead to append the packets to `xmitq` for later processing.
My primary concern, as always, is memory safety. Specifically, I need to determine if this introduces any risks related to uninitialized memory. Let's trace it. The patch passes `xmitq` to `tipc_sk_push_backlog` from existing contexts like `tipc_sk_conn_proto_rcv`, `tipc_sk_proto_rcv`, and `tipc_sk_filter_connect`, implying that this `xmitq` already holds a valid value. Inside `tipc_sk_push_backlog`, we see the following:
```c
+ if (xmitq && in_own_node(net, dnode)) {
+ skb_queue_splice_tail_init(txq, xmitq);
+ return;
+ }
```
Looking at the code, it's just moving SKBs from `txq` to `xmitq`. There are no new allocations, nothing is copied to user space, and no new variables are initialized. It's a pure control flow and queue management change.
Therefore, since this is just a re-arrangement of the data structures that doesn't introduce any new allocations or uses of uninitialized memory, this isn't a KMSAN issue. The potential bugs introduced are of the type that would be caught by KASAN or standard testing; namely, use-after-free, NULL pointer dereferences, or logic errors (like dropped or double-queued packets). Based on this analysis, I will set `NeedsKMSAN` to `false`. I can now finalize the reasoning.
|
| 30/3 | 2026/08/12 13:30 | tool | set-results |
0mArgs:{
"KMSANReasoning": "The patch modifies the `tipc_sk_push_backlog` function to accept an additional `xmitq` argument, allowing it to splice the socket's write queue directly into the transmit queue when sending to the same node, rather than calling `tipc_node_xmit`. This is a control flow and queue management change. It does not introduce any new data structures, allocations, or copying of data to user space. Any potential bugs introduced by this change would be related to queue management (e.g., use-after-free, NULL pointer dereferences, or memory leaks), which are effectively detected by KASAN and standard kernel debugging tools. There is no risk of uninitialized memory usage or info-leaks that would require KMSAN.",
"NeedsKMSAN": false
}Results: {
"KMSANReasoning": "The patch modifies the `tipc_sk_push_backlog` function to accept an additional `xmitq` argument, allowing it to splice the socket's write queue directly into the transmit queue when sending to the same node, rather than calling `tipc_node_xmit`. This is a control flow and queue management change. It does not introduce any new data structures, allocations, or copying of data to user space. Any potential bugs introduced by this change would be related to queue management (e.g., use-after-free, NULL pointer dereferences, or memory leaks), which are effectively detected by KASAN and standard kernel debugging tools. There is no risk of uninitialized memory usage or info-leaks that would require KMSAN.",
"NeedsKMSAN": false
} |
| Total Calls | Total Tokens | Avg Tokens | Total Duration (Seconds) | Avg Duration (Seconds) |
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| Total Calls | Total Duration (Seconds) | Avg Duration (Seconds) |
|---|