AI Trajectory

Trajectory: (Expand/Collapse All)
Seq	Timestamp	Type	Name	Duration
0/0	2026/09/02 16:35	flow	patch-triage	1m Args: null Results: { "EnableConfigs": [ "PPTP", "PPP", "NET_IPGRE_DEMUX" ], "FocusSymbols": [ "pptp_rcv_core", "pptp_rcv", "pptp_create", "pptp_connect", "pptp_bind" ], "KMSANReasoning": "The patch addresses bounds checking and skb pull operations in the PPTP receive path (drivers/net/ppp/pptp.c). Specifically, it ensures that adequate payload bytes are available and pulled into the skb linear area before indexing into skb payload offsets (payload[0] through payload[4] and skb-\u003edata[0] through skb-\u003edata[1]).\n\nThese changes prevent out-of-bounds (OOB) memory reads on truncated or malformed network packets. OOB reads and invalid skb buffer dereferences are directly detected by standard KASAN builds. The patch does not introduce new heap/stack allocations, does not copy kernel memory to user space, and does not alter control flow based on uninitialized memory. Therefore, a dedicated KMSAN session is not required.", "NeedsKMSAN": false, "Reasoning": "The patch modifies packet reception parsing and bounds checking logic in pptp_rcv_core() within the PPTP network protocol driver (drivers/net/ppp/pptp.c), ensuring payload availability checks and pskb_may_pull() calls precede header dereferencing to prevent out-of-bounds reads on truncated packets. This is reachable in standard virtualized environments via AF_PPPOX sockets and GRE packet delivery.", "WorthFuzzing": true }
1/1	2026/09/02 16:35	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit 215595925f298eef5f22d9c7d28b35122da02c8f\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Wed Sep 2 16:35:00 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c\nindex a797a0606f6b4..4fb94a455c574 100644\n--- a/drivers/net/ppp/pptp.c\n+++ b/drivers/net/ppp/pptp.c\n@@ -275,6 +275,7 @@ static int pptp_rcv_core(struct sock sk, struct sk_buff skb)\n \tstruct pppox_sock po = pppox_sk(sk);\n \tstruct pptp_opt opt = \u0026po-\u003eproto.pptp;\n \tint headersize, payload_len, seq;\n+\tunsigned int payload_avail;\n \t__u8 payload;\n \tstruct pptp_gre_header header;\n \n@@ -314,23 +315,34 @@ static int pptp_rcv_core(struct sock sk, struct sk_buff skb)\n \tif (!pskb_may_pull(skb, headersize + payload_len))\n \t\tgoto drop;\n \n-\tpayload = skb-\u003edata + headersize;\n+\tpayload_avail = skb-\u003elen - headersize;\n \t/* check for expected sequence number /\n \tif (seq \u003c opt-\u003eseq_recv + 1 \|\| WRAPPED(opt-\u003eseq_recv, seq)) {\n-\t\tif ((payload[0] == PPP_ALLSTATIONS) \u0026\u0026 (payload[1] == PPP_UI) \u0026\u0026\n-\t\t\t\t(PPP_PROTOCOL(payload) == PPP_LCP) \u0026\u0026\n-\t\t\t\t((payload[4] == PPP_LCP_ECHOREQ) \|\| (payload[4] == PPP_LCP_ECHOREP)))\n-\t\t\tgoto allow_packet;\n+\t\tif (payload_avail \u003e= PPP_HDRLEN + 1) {\n+\t\t\tif (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1))\n+\t\t\t\tgoto drop;\n+\n+\t\t\tpayload = skb-\u003edata + headersize;\n+\t\t\tif (payload[0] == PPP_ALLSTATIONS \u0026\u0026 payload[1] == PPP_UI \u0026\u0026\n+\t\t\t PPP_PROTOCOL(payload) == PPP_LCP \u0026\u0026\n+\t\t\t (payload[4] == PPP_LCP_ECHOREQ \|\| payload[4] == PPP_LCP_ECHOREP))\n+\t\t\t\tgoto allow_packet;\n+\t\t}\n \t} else {\n \t\topt-\u003eseq_recv = seq;\n allow_packet:\n \t\tskb_pull(skb, headersize);\n \n-\t\tif (payload[0] == PPP_ALLSTATIONS \u0026\u0026 payload[1] == PPP_UI) {\n-\t\t\t/ chop off address/control /\n-\t\t\tif (skb-\u003elen \u003c 3)\n+\t\tif (payload_avail \u003e= 2) {\n+\t\t\tif (!pskb_may_pull(skb, 2))\n \t\t\t\tgoto drop;\n-\t\t\tskb_pull(skb, 2);\n+\n+\t\t\tif (skb-\u003edata[0] == PPP_ALLSTATIONS \u0026\u0026 skb-\u003edata[1] == PPP_UI) {\n+\t\t\t\t/ chop off address/control */\n+\t\t\t\tif (skb-\u003elen \u003c 3)\n+\t\t\t\t\tgoto drop;\n+\t\t\t\tskb_pull(skb, 2);\n+\t\t\t}\n \t\t}\n \n \t\tskb-\u003eip_summed = CHECKSUM_NONE;\n" }
2/1	2026/09/02 16:35	agent	patch-evaluator	0m Model: core Args: null Results: { "EnableConfigs": [ "PPTP", "PPP", "NET_IPGRE_DEMUX" ], "FocusSymbols": [ "pptp_rcv_core", "pptp_rcv", "pptp_create", "pptp_connect", "pptp_bind" ], "Reasoning": "The patch modifies packet reception parsing and bounds checking logic in pptp_rcv_core() within the PPTP network protocol driver (drivers/net/ppp/pptp.c), ensuring payload availability checks and pskb_may_pull() calls precede header dereferencing to prevent out-of-bounds reads on truncated packets. This is reachable in standard virtualized environments via AF_PPPOX sockets and GRE packet delivery.", "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 215595925f298eef5f22d9c7d28b35122da02c8f Author: syz-cluster <triage@syzkaller.com> Date: Wed Sep 2 16:35:00 2026 +0000 syz-cluster: applied patch under review diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c index a797a0606f6b4..4fb94a455c574 100644 --- a/drivers/net/ppp/pptp.c +++ b/drivers/net/ppp/pptp.c @@ -275,6 +275,7 @@ static int pptp_rcv_core(struct sock sk, struct sk_buff skb) struct pppox_sock po = pppox_sk(sk); struct pptp_opt opt = &po->proto.pptp; int headersize, payload_len, seq; + unsigned int payload_avail; __u8 payload; struct pptp_gre_header header; @@ -314,23 +315,34 @@ static int pptp_rcv_core(struct sock sk, struct sk_buff skb) if (!pskb_may_pull(skb, headersize + payload_len)) goto drop; - payload = skb->data + headersize; + payload_avail = skb->len - headersize; /* check for expected sequence number / if (seq < opt->seq_recv + 1 \|\| WRAPPED(opt->seq_recv, seq)) { - if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) && - (PPP_PROTOCOL(payload) == PPP_LCP) && - ((payload[4] == PPP_LCP_ECHOREQ) \|\| (payload[4] == PPP_LCP_ECHOREP))) - goto allow_packet; + if (payload_avail >= PPP_HDRLEN + 1) { + if (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1)) + goto drop; + + payload = skb->data + headersize; + if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI && + PPP_PROTOCOL(payload) == PPP_LCP && + (payload[4] == PPP_LCP_ECHOREQ \|\| payload[4] == PPP_LCP_ECHOREP)) + goto allow_packet; + } } else { opt->seq_recv = seq; allow_packet: skb_pull(skb, headersize); - if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) { - / chop off address/control / - if (skb->len < 3) + if (payload_avail >= 2) { + if (!pskb_may_pull(skb, 2)) goto drop; - skb_pull(skb, 2); + + if (skb->data[0] == PPP_ALLSTATIONS && skb->data[1] == PPP_UI) { + / chop off address/control */ + if (skb->len < 3) + goto drop; + skb_pull(skb, 2); + } } skb->ip_summed = CHECKSUM_NONE;
3/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 2702 output: 39 thoughts: 96 Thoughts: Okay, here's my summary, tailored as requested: Digging into that PPTP Patch Alright, let's get down to brass tacks. I need to understand this patch, and my initial focus is on the `drivers/net/ppp/pptp.c` file. That's where the core changes seem to be. Specifically, I'm zeroing in on the `pptp_rcv_core` function. I'll need to dissect that to grasp the impact of the patch. Beyond the code itself, I should make sure there aren't any sneaky interactions. I'll need to check the relevant Kconfig options and symbol definitions within the `drivers/net/ppp/` directory, including that `pptp.c` file. I need to know how this modification interacts with the rest of the PPP stack, and how it might be enabled/disabled. Finally, I'll leverage the tools at my disposal. Grepping through the codebase or strategically using `read-file` to zero in on relevant code sections, dependencies, or potential side effects is the next logical step. It's time to get a more comprehensive understanding of the changes and how they fit into the bigger picture.
4/2	2026/09/02 16:35	tool	read-file	0m Args: { "File": "drivers/net/ppp/pptp.c", "FirstLine": 260, "LineCount": 100 } Results: { "Contents": " 260:\t\tip_select_ident(net, skb, NULL);\n 261:\t\tip_send_check(iph);\n 262:\t\n 263:\t\tip_local_out(net, skb-\u003esk, skb);\n 264:\t\treturn 1;\n 265:\t\n 266:\ttx_error:\n 267:\t\tip_rt_put(rt);\n 268:\ttx_drop:\n 269:\t\tkfree_skb(skb);\n 270:\t\treturn 1;\n 271:\t}\n 272:\t\n 273:\tstatic int pptp_rcv_core(struct sock sk, struct sk_buff skb)\n 274:\t{\n 275:\t\tstruct pppox_sock po = pppox_sk(sk);\n 276:\t\tstruct pptp_opt opt = \u0026po-\u003eproto.pptp;\n 277:\t\tint headersize, payload_len, seq;\n 278:\t\tunsigned int payload_avail;\n 279:\t\t__u8 payload;\n 280:\t\tstruct pptp_gre_header header;\n 281:\t\n 282:\t\tif (!(sk-\u003esk_state \u0026 PPPOX_CONNECTED))\n 283:\t\t\tgoto drop;\n 284:\t\n 285:\t\theader = (struct pptp_gre_header )(skb-\u003edata);\n 286:\t\theadersize = sizeof(header);\n 287:\t\n 288:\t\t/* test if acknowledgement present /\n 289:\t\tif (GRE_IS_ACK(header-\u003egre_hd.flags)) {\n 290:\t\t\t__u32 ack;\n 291:\t\n 292:\t\t\tif (!pskb_may_pull(skb, headersize))\n 293:\t\t\t\tgoto drop;\n 294:\t\t\theader = (struct pptp_gre_header )(skb-\u003edata);\n 295:\t\n 296:\t\t\t/* ack in different place if S = 0 /\n 297:\t\t\tack = GRE_IS_SEQ(header-\u003egre_hd.flags) ? ntohl(header-\u003eack) :\n 298:\t\t\t\t\t\t\t\t ntohl(header-\u003eseq);\n 299:\t\t\tif (ack \u003e opt-\u003eack_recv)\n 300:\t\t\t\topt-\u003eack_recv = ack;\n 301:\t\t\t/ also handle sequence number wrap-around /\n 302:\t\t\tif (WRAPPED(ack, opt-\u003eack_recv))\n 303:\t\t\t\topt-\u003eack_recv = ack;\n 304:\t\t} else {\n 305:\t\t\theadersize -= sizeof(header-\u003eack);\n 306:\t\t}\n 307:\t\t/ test if payload present /\n 308:\t\tif (!GRE_IS_SEQ(header-\u003egre_hd.flags))\n 309:\t\t\tgoto drop;\n 310:\t\n 311:\t\tpayload_len = ntohs(header-\u003epayload_len);\n 312:\t\tseq = ntohl(header-\u003eseq);\n 313:\t\n 314:\t\t/ check for incomplete packet (length smaller than expected) /\n 315:\t\tif (!pskb_may_pull(skb, headersize + payload_len))\n 316:\t\t\tgoto drop;\n 317:\t\n 318:\t\tpayload_avail = skb-\u003elen - headersize;\n 319:\t\t/ check for expected sequence number /\n 320:\t\tif (seq \u003c opt-\u003eseq_recv + 1 \|\| WRAPPED(opt-\u003eseq_recv, seq)) {\n 321:\t\t\tif (payload_avail \u003e= PPP_HDRLEN + 1) {\n 322:\t\t\t\tif (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1))\n 323:\t\t\t\t\tgoto drop;\n 324:\t\n 325:\t\t\t\tpayload = skb-\u003edata + headersize;\n 326:\t\t\t\tif (payload[0] == PPP_ALLSTATIONS \u0026\u0026 payload[1] == PPP_UI \u0026\u0026\n 327:\t\t\t\t PPP_PROTOCOL(payload) == PPP_LCP \u0026\u0026\n 328:\t\t\t\t (payload[4] == PPP_LCP_ECHOREQ \|\| payload[4] == PPP_LCP_ECHOREP))\n 329:\t\t\t\t\tgoto allow_packet;\n 330:\t\t\t}\n 331:\t\t} else {\n 332:\t\t\topt-\u003eseq_recv = seq;\n 333:\tallow_packet:\n 334:\t\t\tskb_pull(skb, headersize);\n 335:\t\n 336:\t\t\tif (payload_avail \u003e= 2) {\n 337:\t\t\t\tif (!pskb_may_pull(skb, 2))\n 338:\t\t\t\t\tgoto drop;\n 339:\t\n 340:\t\t\t\tif (skb-\u003edata[0] == PPP_ALLSTATIONS \u0026\u0026 skb-\u003edata[1] == PPP_UI) {\n 341:\t\t\t\t\t/ chop off address/control /\n 342:\t\t\t\t\tif (skb-\u003elen \u003c 3)\n 343:\t\t\t\t\t\tgoto drop;\n 344:\t\t\t\t\tskb_pull(skb, 2);\n 345:\t\t\t\t}\n 346:\t\t\t}\n 347:\t\n 348:\t\t\tskb-\u003eip_summed = CHECKSUM_NONE;\n 349:\t\t\tskb_set_network_header(skb, skb-\u003ehead-skb-\u003edata);\n 350:\t\t\tppp_input(\u0026po-\u003echan, skb);\n 351:\t\n 352:\t\t\treturn NET_RX_SUCCESS;\n 353:\t\t}\n 354:\tdrop:\n 355:\t\tkfree_skb(skb);\n 356:\t\treturn NET_RX_DROP;\n 357:\t}\n 358:\t\n 359:\tstatic int pptp_rcv(struct sk_buff skb)\n" }
5/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 4632 output: 29 thoughts: 20 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience: Diving into the PPP Networking Landscape Alright, let's get down to brass tacks. I'm focusing on the PPP networking configuration, specifically within the kernel's driver infrastructure. I need to understand the specifics of Point-to-Point Protocol (PPP) configuration. I'm thinking I'll start by digging into the Kconfig files, starting with the `drivers/net/ppp/` directory. That's the logical place to begin, to figure out where PPP support, and by extension, the PPTP (Point-to-Point Tunneling Protocol) options are defined. I need to quickly identify the relevant configuration symbols and dependencies. From there, I can determine the build options and understand how PPTP is integrated and possibly even, the reasoning behind the design.
6/2	2026/09/02 16:35	tool	grepper	0m Args: { "Expression": "pptp\\.o", "PathPrefix": "drivers/net/ppp" } Results: { "Output": "drivers/net/ppp/Makefile=13=obj-$(CONFIG_PPPOE) += pppoe.o\ndrivers/net/ppp/Makefile:14:obj-$(CONFIG_PPTP) += pptp.o\n" }
7/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 4926 output: 28 thoughts: 21 Thoughts: Here's my thought process, as if I were considering this myself: Investigating the PPTP Configuration in the Kernel Okay, so I need to figure out where the `CONFIG_PPTP` option resides in the kernel's build configuration. My first instinct, as an experienced kernel developer, is to go directly to the source. The likely place to start is the PPP networking code, so I'll check inside the `drivers/net/ppp` directory. More specifically, I know that configuration options are typically defined in `Kconfig` files. Therefore, my initial target will be `drivers/net/ppp/Kconfig`. That file should contain the definition for `CONFIG_PPTP` and tell me what dependencies it has. That's the logical starting point for understanding its configuration.
8/2	2026/09/02 16:35	tool	grepper	0m Args: { "Expression": "config PPTP", "PathPrefix": "drivers/net/ppp" } Results: { "Output": "drivers/net/ppp/Kconfig=153=config PPPOE_HASH_BITS\n--\ndrivers/net/ppp/Kconfig-160-\ndrivers/net/ppp/Kconfig:161:config PPTP\ndrivers/net/ppp/Kconfig-162-\ttristate \"PPP over IPv4 (PPTP)\"\n" }
9/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 5236 output: 36 thoughts: 11 Thoughts: Okay, here's my take on those thoughts, tailored for an expert audience: Analyzing the PPTP Kconfig Alright, let's dive in. My immediate thought is, "Let's crack open the Kconfig files related to PPTP." I need to get a clear picture of how PPTP is configured within the kernel build system. I'm assuming we're dealing with a specific kernel version or configuration context, so I'm focusing my mental energy on that. I'll be looking for the dependencies, options, defaults, and potentially any tristate logic associated with the PPTP support. Specifically, I'll be assessing how PPTP support interacts with other network components and security features. My goal is a full picture of PPTP's build time integration.
10/2	2026/09/02 16:35	tool	read-file	0m Args: { "File": "drivers/net/ppp/Kconfig", "FirstLine": 150, "LineCount": 40 } Results: { "Contents": " 150:\t\n 151:\tendchoice\n 152:\t\n 153:\tconfig PPPOE_HASH_BITS\n 154:\t\tint\n 155:\t\tdefault 1 if PPPOE_HASH_BITS_1\n 156:\t\tdefault 2 if PPPOE_HASH_BITS_2\n 157:\t\tdefault 4 if PPPOE_HASH_BITS_4\n 158:\t\tdefault 8 if PPPOE_HASH_BITS_8\n 159:\t\tdefault 4\n 160:\t\n 161:\tconfig PPTP\n 162:\t\ttristate \"PPP over IPv4 (PPTP)\"\n 163:\t\tdepends on NET_IPGRE_DEMUX\n 164:\t\tselect PPPOX\n 165:\t\thelp\n 166:\t\t Support for PPP over IPv4.(Point-to-Point Tunneling Protocol)\n 167:\t\n 168:\t\t This driver requires pppd plugin to work in client mode or\n 169:\t\t modified pptpd (poptop) to work in server mode.\n 170:\t\t See http://accel-pptp.sourceforge.net/ for information how to\n 171:\t\t utilize this module.\n 172:\t\n 173:\tconfig PPPOL2TP\n 174:\t\ttristate \"PPP over L2TP\"\n 175:\t\tdepends on L2TP\n 176:\t\tselect PPPOX\n 177:\t\thelp\n 178:\t\t Support for PPP-over-L2TP socket family. L2TP is a protocol\n 179:\t\t used by ISPs and enterprises to tunnel PPP traffic over UDP\n 180:\t\t tunnels. L2TP is replacing PPTP for VPN uses.\n 181:\tif TTY\n 182:\t\n 183:\tconfig PPP_ASYNC\n 184:\t\ttristate \"PPP support for async serial ports\"\n 185:\t\tselect CRC_CCITT\n 186:\t\thelp\n 187:\t\t Say Y (or M) here if you want to be able to use PPP over standard\n 188:\t\t asynchronous serial ports, such as COM1 or COM2 on a PC. If you use\n 189:\t\t a modem (not a synchronous or ISDN modem) to contact your ISP, you\n" }
11/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 6054 output: 30 thoughts: 15 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience: Investigating `NET_IPGRE_DEMUX` in Kconfig Okay, so I'm looking at something – let's see, it's about the demultiplexing of IP GRE packets. My first thought is to zero in on where this functionality is configured: I need to check `Kconfig` for the `NET_IPGRE_DEMUX` symbol. I'm assuming it's probably a boolean or tristate, but the exact details will come out of inspecting the config. If it's enabled, that of course would suggest we want some demultiplexing; if not, there might be other means of GRE demuxing happening. I need to understand the relationship between this config option and the general GRE implementation. I'll need to dig into the dependencies and the default settings to see the typical use cases and how this aligns with the current architecture.
12/2	2026/09/02 16:35	tool	grepper	0m Args: { "Expression": "config NET_IPGRE_DEMUX", "PathPrefix": "net/" } Results: { "Output": "net/ipv4/Kconfig=162=config NET_IPIP\n--\nnet/ipv4/Kconfig-179-\nnet/ipv4/Kconfig:180:config NET_IPGRE_DEMUX\nnet/ipv4/Kconfig-181-\ttristate \"IP: GRE demultiplexer\"\n" }
13/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 6397 output: 35 thoughts: 23 Thoughts: Here's a summary of my thought process, as if I were the one thinking it: Digging into the GRE Demux Configuration Okay, time to get my hands dirty. I'm going to start by examining the `net/ipv4/Kconfig` file, specifically around the `NET_IPGRE_DEMUX` option. I need to understand how this is configured and what dependencies it might have. This is likely the best place to start to trace the GRE demultiplexing functionality, and understanding its configuration is the first logical step toward understanding its behaviour within the kernel.
14/2	2026/09/02 16:35	tool	read-file	0m Args: { "File": "net/ipv4/Kconfig", "FirstLine": 175, "LineCount": 25 } Results: { "Contents": " 175:\t\n 176:\t\t Saying Y to this option will produce two modules ( = code which can\n 177:\t\t be inserted in and removed from the running kernel whenever you\n 178:\t\t want). Most people won't need this and can say N.\n 179:\t\n 180:\tconfig NET_IPGRE_DEMUX\n 181:\t\ttristate \"IP: GRE demultiplexer\"\n 182:\t\thelp\n 183:\t\t This is helper module to demultiplex GRE packets on GRE version field criteria.\n 184:\t\t Required by ip_gre and pptp modules.\n 185:\t\n 186:\tconfig NET_IP_TUNNEL\n 187:\t\ttristate\n 188:\t\tselect DST_CACHE\n 189:\t\tselect GRO_CELLS\n 190:\t\tdefault n\n 191:\t\n 192:\tconfig NET_IPGRE\n 193:\t\ttristate \"IP: GRE tunnels over IP\"\n 194:\t\tdepends on NET_IPGRE_DEMUX\n 195:\t\tselect NET_IP_TUNNEL\n 196:\t\thelp\n 197:\t\t Tunneling means encapsulating data of one protocol type within\n 198:\t\t another protocol and sending it over a channel that understands the\n 199:\t\t encapsulating protocol. This particular tunneling driver implements\n" }
15/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 6951 output: 33 thoughts: 21 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience: Diving into the pptp.c Packet Reception Okay, time to get my hands dirty and really understand how PPTP packet reception is handled. I need to trace the execution flow and identify the key entry points within `pptp.c`. I'm thinking I'll start by dissecting the functions in the code and map out the packet handling logic. I'm primarily interested in seeing how the datapath works, how the receive functions are called and how the packets make their way up the networking stack. Looking at the code is the only way to get a solid grasp on any nuances in the implementation, particularly for error handling or optimization tricks. I'm expecting this will involve understanding how the GRE packets are demultiplexed and, presumably, passed up to the relevant PPP layer. Let's dig in and find those crucial entry points!
16/2	2026/09/02 16:35	tool	grepper	0m Args: { "Expression": "pptp_", "PathPrefix": "drivers/net/ppp/pptp.c" } Results: { "Output": "drivers/net/ppp/pptp.c=47=static DEFINE_SPINLOCK(chan_lock);\ndrivers/net/ppp/pptp.c-48-\ndrivers/net/ppp/pptp.c:49:static struct proto pptp_sk_proto __read_mostly;\ndrivers/net/ppp/pptp.c:50:static const struct ppp_channel_ops pptp_chan_ops;\ndrivers/net/ppp/pptp.c:51:static const struct proto_ops pptp_ops;\ndrivers/net/ppp/pptp.c-52-\ndrivers/net/ppp/pptp.c=53=static struct pppox_sock lookup_chan(u16 call_id, __be32 s_addr)\n--\ndrivers/net/ppp/pptp.c-55-\tstruct pppox_sock sock;\ndrivers/net/ppp/pptp.c:56:\tstruct pptp_opt opt;\ndrivers/net/ppp/pptp.c-57-\n--\ndrivers/net/ppp/pptp.c=72=static int lookup_chan_dst(u16 call_id, __be32 d_addr)\n--\ndrivers/net/ppp/pptp.c-74-\tstruct pppox_sock sock;\ndrivers/net/ppp/pptp.c:75:\tstruct pptp_opt opt;\ndrivers/net/ppp/pptp.c-76-\tint i;\n--\ndrivers/net/ppp/pptp.c=94=static int add_chan(struct pppox_sock sock,\ndrivers/net/ppp/pptp.c:95:\t\t struct pptp_addr sa)\ndrivers/net/ppp/pptp.c-96-{\n--\ndrivers/net/ppp/pptp.c=124=static void del_chan(struct pppox_sock sock)\n--\ndrivers/net/ppp/pptp.c-131-\ndrivers/net/ppp/pptp.c:132:static struct rtable pptp_route_output(const struct pppox_sock po,\ndrivers/net/ppp/pptp.c-133-\t\t\t\t\tstruct flowi4 fl4)\n--\ndrivers/net/ppp/pptp.c-148-\ndrivers/net/ppp/pptp.c:149:static int pptp_xmit(struct ppp_channel chan, struct sk_buff skb)\ndrivers/net/ppp/pptp.c-150-{\n--\ndrivers/net/ppp/pptp.c-153-\tstruct net net = sock_net(sk);\ndrivers/net/ppp/pptp.c:154:\tstruct pptp_opt opt = \u0026po-\u003eproto.pptp;\ndrivers/net/ppp/pptp.c:155:\tstruct pptp_gre_header hdr;\ndrivers/net/ppp/pptp.c-156-\tunsigned int header_len = sizeof(hdr);\n--\ndrivers/net/ppp/pptp.c-169-\ndrivers/net/ppp/pptp.c:170:\trt = pptp_route_output(po, \u0026fl4);\ndrivers/net/ppp/pptp.c-171-\tif (IS_ERR(rt))\n--\ndrivers/net/ppp/pptp.c-216-\tskb_push(skb, header_len);\ndrivers/net/ppp/pptp.c:217:\thdr = (struct pptp_gre_header )(skb-\u003edata);\ndrivers/net/ppp/pptp.c-218-\n--\ndrivers/net/ppp/pptp.c-272-\ndrivers/net/ppp/pptp.c:273:static int pptp_rcv_core(struct sock sk, struct sk_buff skb)\ndrivers/net/ppp/pptp.c-274-{\ndrivers/net/ppp/pptp.c-275-\tstruct pppox_sock po = pppox_sk(sk);\ndrivers/net/ppp/pptp.c:276:\tstruct pptp_opt opt = \u0026po-\u003eproto.pptp;\ndrivers/net/ppp/pptp.c-277-\tint headersize, payload_len, seq;\n--\ndrivers/net/ppp/pptp.c-279-\t__u8 payload;\ndrivers/net/ppp/pptp.c:280:\tstruct pptp_gre_header header;\ndrivers/net/ppp/pptp.c-281-\n--\ndrivers/net/ppp/pptp.c-284-\ndrivers/net/ppp/pptp.c:285:\theader = (struct pptp_gre_header )(skb-\u003edata);\ndrivers/net/ppp/pptp.c-286-\theadersize = sizeof(header);\n--\ndrivers/net/ppp/pptp.c-293-\t\t\tgoto drop;\ndrivers/net/ppp/pptp.c:294:\t\theader = (struct pptp_gre_header )(skb-\u003edata);\ndrivers/net/ppp/pptp.c-295-\n--\ndrivers/net/ppp/pptp.c-358-\ndrivers/net/ppp/pptp.c:359:static int pptp_rcv(struct sk_buff skb)\ndrivers/net/ppp/pptp.c-360-{\ndrivers/net/ppp/pptp.c-361-\tstruct pppox_sock po;\ndrivers/net/ppp/pptp.c:362:\tstruct pptp_gre_header header;\ndrivers/net/ppp/pptp.c-363-\tstruct iphdr iph;\n--\ndrivers/net/ppp/pptp.c-372-\ndrivers/net/ppp/pptp.c:373:\theader = (struct pptp_gre_header )skb-\u003edata;\ndrivers/net/ppp/pptp.c-374-\n--\ndrivers/net/ppp/pptp.c-393-\ndrivers/net/ppp/pptp.c:394:static int pptp_bind(struct socket sock, struct sockaddr_unsized uservaddr,\ndrivers/net/ppp/pptp.c-395-\t\t int sockaddr_len)\n--\ndrivers/net/ppp/pptp.c-426-\ndrivers/net/ppp/pptp.c:427:static int pptp_connect(struct socket sock, struct sockaddr_unsized uservaddr,\ndrivers/net/ppp/pptp.c-428-\t\t\tint sockaddr_len, int flags)\n--\ndrivers/net/ppp/pptp.c-432-\tstruct pppox_sock po = pppox_sk(sk);\ndrivers/net/ppp/pptp.c:433:\tstruct pptp_opt opt = \u0026po-\u003eproto.pptp;\ndrivers/net/ppp/pptp.c-434-\tstruct rtable rt;\n--\ndrivers/net/ppp/pptp.c-465-\tpo-\u003echan.private = sk;\ndrivers/net/ppp/pptp.c:466:\tpo-\u003echan.ops = \u0026pptp_chan_ops;\ndrivers/net/ppp/pptp.c-467-\ndrivers/net/ppp/pptp.c:468:\trt = pptp_route_output(po, \u0026fl4);\ndrivers/net/ppp/pptp.c-469-\tif (IS_ERR(rt)) {\n--\ndrivers/net/ppp/pptp.c-479-\ndrivers/net/ppp/pptp.c:480:\tpo-\u003echan.hdrlen = 2 + sizeof(struct pptp_gre_header);\ndrivers/net/ppp/pptp.c-481-\tpo-\u003echan.direct_xmit = true;\n--\ndrivers/net/ppp/pptp.c-495-\ndrivers/net/ppp/pptp.c:496:static int pptp_getname(struct socket sock, struct sockaddr uaddr,\ndrivers/net/ppp/pptp.c-497-\tint peer)\n--\ndrivers/net/ppp/pptp.c-512-\ndrivers/net/ppp/pptp.c:513:static int pptp_release(struct socket sock)\ndrivers/net/ppp/pptp.c-514-{\n--\ndrivers/net/ppp/pptp.c-544-\ndrivers/net/ppp/pptp.c:545:static void pptp_sock_destruct(struct sock sk)\ndrivers/net/ppp/pptp.c-546-{\n--\ndrivers/net/ppp/pptp.c-553-\ndrivers/net/ppp/pptp.c:554:static int pptp_create(struct net net, struct socket sock, int kern)\ndrivers/net/ppp/pptp.c-555-{\n--\ndrivers/net/ppp/pptp.c-558-\tstruct pppox_sock po;\ndrivers/net/ppp/pptp.c:559:\tstruct pptp_opt opt;\ndrivers/net/ppp/pptp.c-560-\ndrivers/net/ppp/pptp.c:561:\tsk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, \u0026pptp_sk_proto, kern);\ndrivers/net/ppp/pptp.c-562-\tif (!sk)\n--\ndrivers/net/ppp/pptp.c-567-\tsock-\u003estate = SS_UNCONNECTED;\ndrivers/net/ppp/pptp.c:568:\tsock-\u003eops = \u0026pptp_ops;\ndrivers/net/ppp/pptp.c-569-\ndrivers/net/ppp/pptp.c:570:\tsk-\u003esk_backlog_rcv = pptp_rcv_core;\ndrivers/net/ppp/pptp.c-571-\tsk-\u003esk_state = PPPOX_NONE;\n--\ndrivers/net/ppp/pptp.c-574-\tsk-\u003esk_protocol = PX_PROTO_PPTP;\ndrivers/net/ppp/pptp.c:575:\tsk-\u003esk_destruct = pptp_sock_destruct;\ndrivers/net/ppp/pptp.c-576-\n--\ndrivers/net/ppp/pptp.c-587-\ndrivers/net/ppp/pptp.c:588:static int pptp_ppp_ioctl(struct ppp_channel chan, unsigned int cmd,\ndrivers/net/ppp/pptp.c-589-\tunsigned long arg)\n--\ndrivers/net/ppp/pptp.c-592-\tstruct pppox_sock po = pppox_sk(sk);\ndrivers/net/ppp/pptp.c:593:\tstruct pptp_opt opt = \u0026po-\u003eproto.pptp;\ndrivers/net/ppp/pptp.c-594-\tvoid __user argp = (void __user )arg;\n--\ndrivers/net/ppp/pptp.c-618-\ndrivers/net/ppp/pptp.c:619:static const struct ppp_channel_ops pptp_chan_ops = {\ndrivers/net/ppp/pptp.c:620:\t.start_xmit = pptp_xmit,\ndrivers/net/ppp/pptp.c:621:\t.ioctl = pptp_ppp_ioctl,\ndrivers/net/ppp/pptp.c-622-};\ndrivers/net/ppp/pptp.c-623-\ndrivers/net/ppp/pptp.c:624:static struct proto pptp_sk_proto __read_mostly = {\ndrivers/net/ppp/pptp.c-625-\t.name = \"PPTP\",\n--\ndrivers/net/ppp/pptp.c-629-\ndrivers/net/ppp/pptp.c:630:static const struct proto_ops pptp_ops = {\ndrivers/net/ppp/pptp.c-631-\t.family = AF_PPPOX,\ndrivers/net/ppp/pptp.c-632-\t.owner = THIS_MODULE,\ndrivers/net/ppp/pptp.c:633:\t.release = pptp_release,\ndrivers/net/ppp/pptp.c:634:\t.bind = pptp_bind,\ndrivers/net/ppp/pptp.c:635:\t.connect = pptp_connect,\ndrivers/net/ppp/pptp.c-636-\t.socketpair = sock_no_socketpair,\ndrivers/net/ppp/pptp.c-637-\t.accept = sock_no_accept,\ndrivers/net/ppp/pptp.c:638:\t.getname = pptp_getname,\ndrivers/net/ppp/pptp.c-639-\t.listen = sock_no_listen,\n--\ndrivers/net/ppp/pptp.c-649-\ndrivers/net/ppp/pptp.c:650:static const struct pppox_proto pppox_pptp_proto = {\ndrivers/net/ppp/pptp.c:651:\t.create = pptp_create,\ndrivers/net/ppp/pptp.c-652-\t.owner = THIS_MODULE,\n--\ndrivers/net/ppp/pptp.c-654-\ndrivers/net/ppp/pptp.c:655:static const struct gre_protocol gre_pptp_protocol = {\ndrivers/net/ppp/pptp.c:656:\t.handler = pptp_rcv,\ndrivers/net/ppp/pptp.c-657-};\ndrivers/net/ppp/pptp.c-658-\ndrivers/net/ppp/pptp.c:659:static int __init pptp_init_module(void)\ndrivers/net/ppp/pptp.c-660-{\n--\ndrivers/net/ppp/pptp.c-667-\ndrivers/net/ppp/pptp.c:668:\terr = gre_add_protocol(\u0026gre_pptp_protocol, GREPROTO_PPTP);\ndrivers/net/ppp/pptp.c-669-\tif (err) {\n--\ndrivers/net/ppp/pptp.c-673-\ndrivers/net/ppp/pptp.c:674:\terr = proto_register(\u0026pptp_sk_proto, 0);\ndrivers/net/ppp/pptp.c-675-\tif (err) {\n--\ndrivers/net/ppp/pptp.c-679-\ndrivers/net/ppp/pptp.c:680:\terr = register_pppox_proto(PX_PROTO_PPTP, \u0026pppox_pptp_proto);\ndrivers/net/ppp/pptp.c-681-\tif (err) {\n--\ndrivers/net/ppp/pptp.c-688-out_unregister_sk_proto:\ndrivers/net/ppp/pptp.c:689:\tproto_unregister(\u0026pptp_sk_proto);\ndrivers/net/ppp/pptp.c-690-out_gre_del_protocol:\ndrivers/net/ppp/pptp.c:691:\tgre_del_protocol(\u0026gre_pptp_protocol, GREPROTO_PPTP);\ndrivers/net/ppp/pptp.c-692-out_mem_free:\n--\ndrivers/net/ppp/pptp.c-697-\ndrivers/net/ppp/pptp.c:698:static void __exit pptp_exit_module(void)\ndrivers/net/ppp/pptp.c-699-{\ndrivers/net/ppp/pptp.c-700-\tunregister_pppox_proto(PX_PROTO_PPTP);\ndrivers/net/ppp/pptp.c:701:\tproto_unregister(\u0026pptp_sk_proto);\ndrivers/net/ppp/pptp.c:702:\tgre_del_protocol(\u0026gre_pptp_protocol, GREPROTO_PPTP);\ndrivers/net/ppp/pptp.c-703-\tvfree(callid_sock);\n--\ndrivers/net/ppp/pptp.c-705-\ndrivers/net/ppp/pptp.c:706:module_init(pptp_init_module);\ndrivers/net/ppp/pptp.c:707:module_exit(pptp_exit_module);\ndrivers/net/ppp/pptp.c-708-\n" }
17/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 11340 output: 38 thoughts: 114 Thoughts: Analyzing the PPTP GRE Packet Reception Okay, let's break this down. My focus right now is on how PPTP traffic is handled at the network level, specifically the reception of GRE packets. From what I understand, the function `pptp_rcv` is the designated handler for GRE packets designated with `GREPROTO_PPTP`. Essentially, it's the gatekeeper for PPTP traffic coming in over GRE. My initial thought is that `pptp_rcv` needs to process incoming GRE packets and direct them appropriately, which it accomplishes by finding the relevant socket and passing the `skb` (socket buffer) to `sk_receive_skb`. This function then likely invokes the socket's backlog handler. This part is particularly important to investigate as it's the core of how packets are routed. `sk->sk_backlog_rcv = pptp_rcv_core` tells me that `pptp_rcv_core` is the backlog handler in this context. Now I should check exactly what the implementation of `pptp_rcv` does. I will check pptp.c lines 358-392 and dissect its implementation.
18/2	2026/09/02 16:35	tool	read-file	0m Args: { "File": "drivers/net/ppp/pptp.c", "FirstLine": 358, "LineCount": 40 } Results: { "Contents": " 358:\t\n 359:\tstatic int pptp_rcv(struct sk_buff skb)\n 360:\t{\n 361:\t\tstruct pppox_sock po;\n 362:\t\tstruct pptp_gre_header header;\n 363:\t\tstruct iphdr iph;\n 364:\t\n 365:\t\tif (skb-\u003epkt_type != PACKET_HOST)\n 366:\t\t\tgoto drop;\n 367:\t\n 368:\t\tif (!pskb_may_pull(skb, 12))\n 369:\t\t\tgoto drop;\n 370:\t\n 371:\t\tiph = ip_hdr(skb);\n 372:\t\n 373:\t\theader = (struct pptp_gre_header )skb-\u003edata;\n 374:\t\n 375:\t\tif (header-\u003egre_hd.protocol != GRE_PROTO_PPP \|\| / PPTP-GRE protocol for PPTP /\n 376:\t\t\tGRE_IS_CSUM(header-\u003egre_hd.flags) \|\| / flag CSUM should be clear /\n 377:\t\t\tGRE_IS_ROUTING(header-\u003egre_hd.flags) \|\| / flag ROUTING should be clear /\n 378:\t\t\t!GRE_IS_KEY(header-\u003egre_hd.flags) \|\| / flag KEY should be set /\n 379:\t\t\t(header-\u003egre_hd.flags \u0026 GRE_FLAGS)) / flag Recursion Ctrl should be clear /\n 380:\t\t\t/ if invalid, discard this packet /\n 381:\t\t\tgoto drop;\n 382:\t\n 383:\t\tpo = lookup_chan(ntohs(header-\u003ecall_id), iph-\u003esaddr);\n 384:\t\tif (po) {\n 385:\t\t\tskb_dst_drop(skb);\n 386:\t\t\tnf_reset_ct(skb);\n 387:\t\t\treturn sk_receive_skb(\u0026po-\u003esk, skb, 0);\n 388:\t\t}\n 389:\tdrop:\n 390:\t\tkfree_skb(skb);\n 391:\t\treturn NET_RX_DROP;\n 392:\t}\n 393:\t\n 394:\tstatic int pptp_bind(struct socket sock, struct sockaddr_unsized uservaddr,\n 395:\t\t\t int sockaddr_len)\n 396:\t{\n 397:\t\tstruct sock sk = sock-\u003esk;\n" }
19/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 12395 output: 31 thoughts: 605 Thoughts: Fuzzing the PPTP GRE Handler Okay, so I've been looking at this patch for `pptp_rcv_core`, and it's got my attention. It's a fix related to packet length and `pskb_may_pull` checks when the kernel is processing received PPTP GRE packets. Specifically, it seems like the check now ensures that the payload availability is greater or equal than required, meaning `payload_avail >= PPP_HDRLEN + 1` and `payload_avail >= 2` are met before the code accesses the payload/data. This sounds like a functional change to packet parsing logic and bounds checking, which is a prime target for fuzzing. Given that PPTP sockets are standard network sockets and are reachable in a virtualized environment like QEMU via standard socket system calls (think `socket(AF_PPPOX, ..., PX_PROTO_PPTP)`), receiving GRE packets (e.g., over loopback or a netns), this seems like a solid opportunity. The fact that the vulnerability is in the core network implementation, specifically within PPP and PPTP, further strengthens the case. Now, let's nail down what functions to focus on. Obviously, `pptp_rcv_core` is a key candidate. I should also consider `pptp_rcv`, since it seems like `pptp_rcv_core` is a static function that's being used by `pptp_rcv`. Other interesting functions to include in the fuzzing focus could be `pptp_connect`, `pptp_bind`, `pptp_create`, and `pptp_xmit`. I'll have to investigate if they're static, inlined, or if I should just include them all for now. I know that `pptp_rcv_core` is static, but the address is taken by the `sk->sk_backlog_rcv = pptp_rcv_core;` assignment. Similarly, `pptp_rcv` is static, with its address being used by `gre_pptp_protocol.handler = pptp_rcv`. I should probably check the symbols defined in `pptp.c` too. Next, I need to check the relevant Kconfig options. It looks like `PPTP` depends on `NET_IPGRE_DEMUX` and selects `PPPOX`. `NET_IPGRE_DEMUX` itself is in the `net/ipv4/Kconfig` and is also tristate. I also need to make sure the base `PPP` subsystem itself (`CONFIG_PPP`) is enabled. I should probably double-check the `drivers/net/ppp/Kconfig` file to see what menus and dependencies there are as well. This should give me a complete picture of the build requirements for successful fuzzing.
20/2	2026/09/02 16:35	tool	grepper	0m Args: { "Expression": "menuconfig PPP\|if PPP", "PathPrefix": "drivers/net/ppp" } Results: { "Output": "drivers/net/ppp/Kconfig=6=config PPP\n--\ndrivers/net/ppp/Kconfig-34-\ndrivers/net/ppp/Kconfig:35:if PPP\ndrivers/net/ppp/Kconfig-36-\n--\ndrivers/net/ppp/Kconfig=153=config PPPOE_HASH_BITS\ndrivers/net/ppp/Kconfig-154-\tint\ndrivers/net/ppp/Kconfig:155:\tdefault 1 if PPPOE_HASH_BITS_1\ndrivers/net/ppp/Kconfig:156:\tdefault 2 if PPPOE_HASH_BITS_2\ndrivers/net/ppp/Kconfig:157:\tdefault 4 if PPPOE_HASH_BITS_4\ndrivers/net/ppp/Kconfig:158:\tdefault 8 if PPPOE_HASH_BITS_8\ndrivers/net/ppp/Kconfig-159-\tdefault 4\n" }
21/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 13868 output: 24 thoughts: 25 Thoughts: Here's my thought process, as requested: Navigating the Kernel's Network Configuration Okay, so I need to figure out how the PPP (Point-to-Point Protocol) drivers are incorporated into this kernel build. Given my experience, the Kconfig files are the most logical place to start. I'll take a look at `drivers/net/Kconfig`. This should reveal the dependency or inclusion logic for the PPP-related options. This file likely controls the visibility and configurability of the PPP drivers during the kernel configuration process. I'm expecting to find a conditional statement or a menu entry that points me to where the PPP configuration elements are defined, if not defined directly within this `Kconfig` file itself.
22/2	2026/09/02 16:35	tool	grepper	0m Args: { "Expression": "ppp", "PathPrefix": "drivers/net" } Results: { "Output": "\nFull output is too long, showing 500 out of 5302 lines.\nUse more precise expression if possible.\n\ndrivers/net/Kconfig=526=source \"drivers/net/plip/Kconfig\"\ndrivers/net/Kconfig-527-\ndrivers/net/Kconfig:528:source \"drivers/net/ppp/Kconfig\"\ndrivers/net/Kconfig-529-\n--\ndrivers/net/Makefile=57=obj-$(CONFIG_PLIP) += plip/\ndrivers/net/Makefile:58:obj-$(CONFIG_PPP) += ppp/\ndrivers/net/Makefile:59:obj-$(CONFIG_PPP_ASYNC) += ppp/\ndrivers/net/Makefile:60:obj-$(CONFIG_PPP_BSDCOMP) += ppp/\ndrivers/net/Makefile:61:obj-$(CONFIG_PPP_DEFLATE) += ppp/\ndrivers/net/Makefile:62:obj-$(CONFIG_PPP_MPPE) += ppp/\ndrivers/net/Makefile:63:obj-$(CONFIG_PPP_SYNC_TTY) += ppp/\ndrivers/net/Makefile:64:obj-$(CONFIG_PPPOE) += ppp/\ndrivers/net/Makefile:65:obj-$(CONFIG_PPPOL2TP) += ppp/\ndrivers/net/Makefile:66:obj-$(CONFIG_PPTP) += ppp/\ndrivers/net/Makefile-67-obj-$(CONFIG_SLIP) += slip/\n--\ndrivers/net/dsa/yt921x.c=3857=yt921x_dsa_port_set_default_prio(struct dsa_switch ds, int port, u8 prio)\n--\ndrivers/net/dsa/yt921x.c-3875-\ndrivers/net/dsa/yt921x.c:3876:static int __maybe_unused appprios_cmp(const void a, const void b)\ndrivers/net/dsa/yt921x.c-3877-{\n--\ndrivers/net/dsa/yt921x.c=3882=yt921x_dsa_port_get_apptrust(struct dsa_switch ds, int port, u8 sel,\n--\ndrivers/net/dsa/yt921x.c-3885-\tstruct yt921x_priv priv = to_yt921x_priv(ds);\ndrivers/net/dsa/yt921x.c:3886:\tu8 appprios[2][2] = {};\ndrivers/net/dsa/yt921x.c-3887-\tint nsel;\n--\ndrivers/net/dsa/yt921x.c-3897-\ndrivers/net/dsa/yt921x.c:3898:\tappprios[0][0] = IEEE_8021QAZ_APP_SEL_DSCP;\ndrivers/net/dsa/yt921x.c:3899:\tappprios[0][1] = (val \u003e\u003e (3 * YT921X_APP_SEL_DSCP)) \u0026 7;\ndrivers/net/dsa/yt921x.c:3900:\tappprios[1][0] = DCB_APP_SEL_PCP;\ndrivers/net/dsa/yt921x.c:3901:\tappprios[1][1] = (val \u003e\u003e (3 * YT921X_APP_SEL_CVLAN_PCP)) \u0026 7;\ndrivers/net/dsa/yt921x.c:3902:\tsort(appprios, ARRAY_SIZE(appprios), sizeof(appprios[0]), appprios_cmp,\ndrivers/net/dsa/yt921x.c-3903-\t NULL);\n--\ndrivers/net/dsa/yt921x.c-3905-\tnsel = 0;\ndrivers/net/dsa/yt921x.c:3906:\tfor (int i = 0; i \u003c ARRAY_SIZE(appprios) \u0026\u0026 appprios[i][1]; i++) {\ndrivers/net/dsa/yt921x.c:3907:\t\tsel[nsel] = appprios[i][0];\ndrivers/net/dsa/yt921x.c-3908-\t\tnsel++;\n--\ndrivers/net/ethernet/airoha/airoha_eth.c-14-#include \u003cnet/pkt_cls.h\u003e\ndrivers/net/ethernet/airoha/airoha_eth.c:15:#include \u003cuapi/linux/ppp_defs.h\u003e\ndrivers/net/ethernet/airoha/airoha_eth.c-16-\n--\ndrivers/net/ethernet/airoha/airoha_eth.h=313=struct airoha_foe_mac_info {\n--\ndrivers/net/ethernet/airoha/airoha_eth.h-315-\ndrivers/net/ethernet/airoha/airoha_eth.h:316:\tu16 pppoe_id;\ndrivers/net/ethernet/airoha/airoha_eth.h-317-\tu16 src_mac_lo;\n--\ndrivers/net/ethernet/airoha/airoha_eth.h=473=struct airoha_flow_data {\n--\ndrivers/net/ethernet/airoha/airoha_eth.h-500-\t\tu8 num;\ndrivers/net/ethernet/airoha/airoha_eth.h:501:\t} pppoe;\ndrivers/net/ethernet/airoha/airoha_eth.h-502-};\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c=342=static int airoha_ppe_foe_entry_prepare(struct airoha_eth eth,\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-359-\t FIELD_PREP(AIROHA_FOE_IB1_BIND_VPM, data-\u003evlan.num) \|\ndrivers/net/ethernet/airoha/airoha_ppe.c:360:\t FIELD_PREP(AIROHA_FOE_IB1_BIND_PPPOE, data-\u003epppoe.num) \|\ndrivers/net/ethernet/airoha/airoha_ppe.c-361-\t AIROHA_FOE_IB1_BIND_TTL;\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-455-\t\tmac_info = (struct airoha_foe_mac_info )l2;\ndrivers/net/ethernet/airoha/airoha_ppe.c:456:\t\tmac_info-\u003epppoe_id = data-\u003epppoe.sid;\ndrivers/net/ethernet/airoha/airoha_ppe.c-457-\t} else {\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-459-\t\t\t\t FIELD_PREP(AIROHA_FOE_MAC_PPPOE_ID,\ndrivers/net/ethernet/airoha/airoha_ppe.c:460:\t\t\t\t\t data-\u003epppoe.sid);\ndrivers/net/ethernet/airoha/airoha_ppe.c-461-\t}\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-473-\t\tl2-\u003eetype \|= !data-\u003evlan.num ? BIT(15) : 0;\ndrivers/net/ethernet/airoha/airoha_ppe.c:474:\t} else if (data-\u003epppoe.num) {\ndrivers/net/ethernet/airoha/airoha_ppe.c-475-\t\tl2-\u003eetype = ETH_P_PPP_SES;\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c=1088=static int airoha_ppe_flow_offload_replace(struct airoha_eth eth,\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-1177-\t\tcase FLOW_ACTION_PPPOE_PUSH:\ndrivers/net/ethernet/airoha/airoha_ppe.c:1178:\t\t\tif (data.pppoe.num == 1 \|\| data.vlan.num == 2)\ndrivers/net/ethernet/airoha/airoha_ppe.c-1179-\t\t\t\treturn -EOPNOTSUPP;\ndrivers/net/ethernet/airoha/airoha_ppe.c-1180-\ndrivers/net/ethernet/airoha/airoha_ppe.c:1181:\t\t\tdata.pppoe.sid = act-\u003epppoe.sid;\ndrivers/net/ethernet/airoha/airoha_ppe.c:1182:\t\t\tdata.pppoe.num++;\ndrivers/net/ethernet/airoha/airoha_ppe.c-1183-\t\t\tbreak;\n--\ndrivers/net/ethernet/broadcom/bcmsysport.c=191=static const struct bcm_sysport_stats bcm_sysport_gstrings_stats[] = {\n--\ndrivers/net/ethernet/broadcom/bcmsysport.c-229-\tSTAT_MIB_RX(\"rx_unicast\", mib.rx.uc),\ndrivers/net/ethernet/broadcom/bcmsysport.c:230:\tSTAT_MIB_RX(\"rx_ppp\", mib.rx.ppp),\ndrivers/net/ethernet/broadcom/bcmsysport.c-231-\tSTAT_MIB_RX(\"rx_crc\", mib.rx.rcrc),\n--\ndrivers/net/ethernet/broadcom/bcmsysport.h=511=struct bcm_sysport_rx_counters {\n--\ndrivers/net/ethernet/broadcom/bcmsysport.h-529-\tu32\tuc;\t\t/ RO # of unicast pkt /\ndrivers/net/ethernet/broadcom/bcmsysport.h:530:\tu32\tppp;\t\t/ RO # of PPP pkt /\ndrivers/net/ethernet/broadcom/bcmsysport.h-531-\tu32\trcrc;\t\t/ RO (0x470),# of CRC match pkt /\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c=2118=static void bnx2x_update_pfc_nig(struct link_params params,\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2121-{\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c:2122:\tu32 xcm_mask = 0, ppp_enable = 0, pause_enable = 0, llfc_out_en = 0;\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2123-\tu32 llfc_enable = 0, xcm_out_en = 0, hwpfc_enable = 0;\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2145-\t\tif (CHIP_IS_E3(bp))\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c:2146:\t\t\tppp_enable = 0;\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2147-\t\telse\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c:2148:\t\t\tppp_enable = 1;\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2149-\t\txcm_mask \u0026= ~(port ? NIG_LLH1_XCM_MASK_REG_LLH1_XCM_MASK_BCN :\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2176-\tREG_WR(bp, port ? NIG_REG_PPP_ENABLE_1 :\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c:2177:\t NIG_REG_PPP_ENABLE_0, ppp_enable);\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2178-\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h=871=extern const u32 dmae_reg_go_c[];\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2062-#define NIG_REG_LED_MODE_P0\t\t\t\t\t 0x102f0\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h:2063:/* [RW 3] for port0 enable for llfc ppp and pause. b0 - brb1 enable; b1-\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2064- tsdm enable; b2- usdm enable /\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2067-/ [RW 1] SAFC enable for port0. This register may get 1 only when\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h:2068: ~ppp_enable.ppp_enable = 0 and pause_enable.pause_enable =0 for the same\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2069- port /\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2640-/ [RW 1] Pause enable for port0. This register may get 1 only when\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h:2641: ~safc_enable.safc_enable = 0 and ppp_enable.ppp_enable =0 for the same\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2642- port /\n--\ndrivers/net/ethernet/broadcom/genet/bcmgenet.c=1073=static const struct bcmgenet_stats bcmgenet_gstrings_stats[] = {\n--\ndrivers/net/ethernet/broadcom/genet/bcmgenet.c-1116-\tSTAT_GENET_MIB_RX(\"rx_unicast\", mib.rx.uc),\ndrivers/net/ethernet/broadcom/genet/bcmgenet.c:1117:\tSTAT_GENET_MIB_RX(\"rx_ppp\", mib.rx.ppp),\ndrivers/net/ethernet/broadcom/genet/bcmgenet.c-1118-\tSTAT_GENET_MIB_RX(\"rx_crc\", mib.rx.rcrc),\n--\ndrivers/net/ethernet/broadcom/genet/bcmgenet.h=95=struct bcmgenet_rx_counters {\n--\ndrivers/net/ethernet/broadcom/genet/bcmgenet.h-113-\tu32\tuc;\t\t/ RO # of unicast pkt /\ndrivers/net/ethernet/broadcom/genet/bcmgenet.h:114:\tu32\tppp;\t\t/ RO # of PPP pkt /\ndrivers/net/ethernet/broadcom/genet/bcmgenet.h-115-\tu32\trcrc;\t\t/ RO (0x470),# of CRC match pkt /\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h=205=struct port_stats {\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h-222-\tu64 tx_pause; / # of transmitted pause frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:223:\tu64 tx_ppp0; / # of transmitted PPP prio 0 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:224:\tu64 tx_ppp1; / # of transmitted PPP prio 1 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:225:\tu64 tx_ppp2; / # of transmitted PPP prio 2 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:226:\tu64 tx_ppp3; / # of transmitted PPP prio 3 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:227:\tu64 tx_ppp4; / # of transmitted PPP prio 4 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:228:\tu64 tx_ppp5; / # of transmitted PPP prio 5 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:229:\tu64 tx_ppp6; / # of transmitted PPP prio 6 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:230:\tu64 tx_ppp7; / # of transmitted PPP prio 7 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h-231-\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h-252-\tu64 rx_pause; / # of received pause frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:253:\tu64 rx_ppp0; / # of received PPP prio 0 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:254:\tu64 rx_ppp1; / # of received PPP prio 1 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:255:\tu64 rx_ppp2; / # of received PPP prio 2 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:256:\tu64 rx_ppp3; / # of received PPP prio 3 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:257:\tu64 rx_ppp4; / # of received PPP prio 4 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:258:\tu64 rx_ppp5; / # of received PPP prio 5 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:259:\tu64 rx_ppp6; / # of received PPP prio 6 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:260:\tu64 rx_ppp7; / # of received PPP prio 7 frames /\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h-261-\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c=45=static const char stats_strings[][ETH_GSTRING_LEN] = {\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c-62-\t\"tx_pause_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:63:\t\"tx_ppp0_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:64:\t\"tx_ppp1_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:65:\t\"tx_ppp2_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:66:\t\"tx_ppp3_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:67:\t\"tx_ppp4_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:68:\t\"tx_ppp5_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:69:\t\"tx_ppp6_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:70:\t\"tx_ppp7_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c-71-\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c-93-\t\"rx_pause_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:94:\t\"rx_ppp0_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:95:\t\"rx_ppp1_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:96:\t\"rx_ppp2_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:97:\t\"rx_ppp3_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:98:\t\"rx_ppp4_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:99:\t\"rx_ppp5_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:100:\t\"rx_ppp6_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:101:\t\"rx_ppp7_frames \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c-102-\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c=6345=void t4_get_port_stats(struct adapter adap, int idx, struct port_stats p)\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c-6370-\tp-\u003etx_pause = GET_STAT(TX_PORT_PAUSE);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6371:\tp-\u003etx_ppp0 = GET_STAT(TX_PORT_PPP0);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6372:\tp-\u003etx_ppp1 = GET_STAT(TX_PORT_PPP1);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6373:\tp-\u003etx_ppp2 = GET_STAT(TX_PORT_PPP2);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6374:\tp-\u003etx_ppp3 = GET_STAT(TX_PORT_PPP3);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6375:\tp-\u003etx_ppp4 = GET_STAT(TX_PORT_PPP4);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6376:\tp-\u003etx_ppp5 = GET_STAT(TX_PORT_PPP5);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6377:\tp-\u003etx_ppp6 = GET_STAT(TX_PORT_PPP6);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6378:\tp-\u003etx_ppp7 = GET_STAT(TX_PORT_PPP7);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c-6379-\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c-6404-\tp-\u003erx_pause = GET_STAT(RX_PORT_PAUSE);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6405:\tp-\u003erx_ppp0 = GET_STAT(RX_PORT_PPP0);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6406:\tp-\u003erx_ppp1 = GET_STAT(RX_PORT_PPP1);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6407:\tp-\u003erx_ppp2 = GET_STAT(RX_PORT_PPP2);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6408:\tp-\u003erx_ppp3 = GET_STAT(RX_PORT_PPP3);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6409:\tp-\u003erx_ppp4 = GET_STAT(RX_PORT_PPP4);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6410:\tp-\u003erx_ppp5 = GET_STAT(RX_PORT_PPP5);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6411:\tp-\u003erx_ppp6 = GET_STAT(RX_PORT_PPP6);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6412:\tp-\u003erx_ppp7 = GET_STAT(RX_PORT_PPP7);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c-6413-\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h=3210=struct fw_port_stats_cmd {\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h-3241-\t\t\t__be64 tx_pause;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3242:\t\t\t__be64 tx_ppp0;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3243:\t\t\t__be64 tx_ppp1;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3244:\t\t\t__be64 tx_ppp2;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3245:\t\t\t__be64 tx_ppp3;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3246:\t\t\t__be64 tx_ppp4;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3247:\t\t\t__be64 tx_ppp5;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3248:\t\t\t__be64 tx_ppp6;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3249:\t\t\t__be64 tx_ppp7;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h-3250-\t\t\t__be64 rx_bytes;\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h-3267-\t\t\t__be64 rx_pause;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3268:\t\t\t__be64 rx_ppp0;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3269:\t\t\t__be64 rx_ppp1;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3270:\t\t\t__be64 rx_ppp2;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3271:\t\t\t__be64 rx_ppp3;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3272:\t\t\t__be64 rx_ppp4;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3273:\t\t\t__be64 rx_ppp5;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3274:\t\t\t__be64 rx_ppp6;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3275:\t\t\t__be64 rx_ppp7;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h-3276-\t\t\t__be64 rx_less_64b;\n--\ndrivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h=213=struct dpaa2_fapr {\n--\ndrivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h-236-\tu8 mpls_offset_1;\ndrivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h:237:\tu8 pppoe_offset;\ndrivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h-238-\t/ 64-bit word 5 /\n--\ndrivers/net/ethernet/freescale/fman/fman.h=114=struct fman_prs_result {\n--\ndrivers/net/ethernet/freescale/fman/fman.h-134-\tu8 etype_off;\t\t/ ETYPE offset /\ndrivers/net/ethernet/freescale/fman/fman.h:135:\tu8 pppoe_off;\t\t/ PPP offset /\ndrivers/net/ethernet/freescale/fman/fman.h-136-\tu8 mpls_off[2];\t\t/ MPLS offset /\n--\ndrivers/net/ethernet/freescale/fs_enet/fs_enet.h=74=struct fs_ops {\n--\ndrivers/net/ethernet/freescale/fs_enet/fs_enet.h-97- /\ndrivers/net/ethernet/freescale/fs_enet/fs_enet.h:98:#define MAX_MTU 1508\t\t/* Allow fullsized pppoe packets over VLAN /\ndrivers/net/ethernet/freescale/fs_enet/fs_enet.h-99-#define MIN_MTU 46\t\t/ this is data size /\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c=47=static struct hns3_dbg_cmd_info hns3_dbg_cmd[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c-222-\t{\ndrivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c:223:\t\t.name = \"ppp\",\ndrivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c-224-\t\t.cmd = HNAE3_DBG_CMD_REG_PPP,\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c=390=static const struct hclge_dbg_dfx_message hclge_dbg_rtc_reg[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-419-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:420:static const struct hclge_dbg_dfx_message hclge_dbg_ppp_reg[] = {\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-421-\t{false, \"Reserved\"},\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c=664=static const struct hclge_dbg_reg_type_info hclge_dbg_reg_info[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-710-\t{ .cmd = HNAE3_DBG_CMD_REG_PPP,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:711:\t .dfx_msg = \u0026hclge_dbg_ppp_reg[0],\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:712:\t .reg_msg = { .msg_num = ARRAY_SIZE(hclge_dbg_ppp_reg),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-713-\t\t .offset = HCLGE_DBG_DFX_PPP_OFFSET,\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c=1249=static int hclge_dbg_dump_rtc_reg_cmd(struct seq_file s, void data)\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-1253-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:1254:static int hclge_dbg_dump_ppp_reg_cmd(struct seq_file s, void data)\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-1255-{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c=2938=static const struct hclge_dbg_func hclge_dbg_cmd_func[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-3044-\t\t.cmd = HNAE3_DBG_CMD_REG_PPP,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:3045:\t\t.dbg_read_func = hclge_dbg_dump_ppp_reg_cmd,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-3046-\t},\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=208=static const struct hclge_hw_error hclge_ncsi_err_int[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-217-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:218:static const struct hclge_hw_error hclge_ppp_mpf_abnormal_int_st1[] = {\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-219-\t{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-347-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:348:static const struct hclge_hw_error hclge_ppp_pf_abnormal_int[] = {\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-349-\t{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-361-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:362:static const struct hclge_hw_error hclge_ppp_mpf_abnormal_int_st3[] = {\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-363-\t{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=846=static const struct hclge_hw_error hclge_ssu_com_err_int[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-852-\t\t.int_msk = BIT(1),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:853:\t\t.msg = \"ppp_mb_num_err\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-854-\t\t.reset_level = HNAE3_NONE_RESET\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-856-\t\t.int_msk = BIT(2),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:857:\t\t.msg = \"ppp_mbid_err\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-858-\t\t.reset_level = HNAE3_GLOBAL_RESET\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-860-\t\t.int_msk = BIT(3),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:861:\t\t.msg = \"ppp_rlt_mac_err\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-862-\t\t.reset_level = HNAE3_GLOBAL_RESET\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-864-\t\t.int_msk = BIT(4),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:865:\t\t.msg = \"ppp_rlt_host_err\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-866-\t\t.reset_level = HNAE3_GLOBAL_RESET\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=1879=static int hclge_config_igu_egu_hw_err_int(struct hclge_dev hdev, bool en)\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1917-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:1918:static int hclge_config_ppp_error_interrupt(struct hclge_dev hdev, u32 cmd,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1919-\t\t\t\t\t bool en)\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1966-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:1967:static int hclge_config_ppp_hw_err_int(struct hclge_dev hdev, bool en)\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1968-{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1970-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:1971:\tret = hclge_config_ppp_error_interrupt(hdev, HCLGE_PPP_CMD0_INT_CMD,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1972-\t\t\t\t\t en);\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1975-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:1976:\tret = hclge_config_ppp_error_interrupt(hdev, HCLGE_PPP_CMD1_INT_CMD,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1977-\t\t\t\t\t en);\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=2250=static int hclge_handle_mpf_ras_error(struct hclge_dev hdev,\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2330-\t\thclge_log_error(dev, \"PPP_MPF_ABNORMAL_INT_ST1\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:2331:\t\t\t\t\u0026hclge_ppp_mpf_abnormal_int_st1[0], status,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2332-\t\t\t\t\u0026ae_dev-\u003ehw_err_reset_req);\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2336-\t\thclge_log_error(dev, \"PPP_MPF_ABNORMAL_INT_ST3\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:2337:\t\t\t\t\u0026hclge_ppp_mpf_abnormal_int_st3[0], status,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2338-\t\t\t\t\u0026ae_dev-\u003ehw_err_reset_req);\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=2716=static const struct hclge_hw_blk hw_blk[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2723-\t\t.name = \"PPP\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:2724:\t\t.config_err_int = hclge_config_ppp_hw_err_int,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2725-\t}, {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=2975=static int hclge_handle_pf_msix_error(struct hclge_dev hdev,\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-3005-\t\thclge_log_error(dev, \"PPP_PF_ABNORMAL_INT_ST0\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:3006:\t\t\t\t\u0026hclge_ppp_pf_abnormal_int[0],\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-3007-\t\t\t\tstatus, reset_requests);\n--\ndrivers/net/ethernet/intel/ice/ice.h-56-#include \u003cnet/gtp.h\u003e\ndrivers/net/ethernet/intel/ice/ice.h:57:#include \u003clinux/ppp_defs.h\u003e\ndrivers/net/ethernet/intel/ice/ice.h-58-#include \"ice_devids.h\"\n--\ndrivers/net/ethernet/intel/ice/ice_fdir.h=132=struct ice_fdir_udp_gtp {\n--\ndrivers/net/ethernet/intel/ice/ice_fdir.h-142-\t\tspare:4;\ndrivers/net/ethernet/intel/ice/ice_fdir.h:143:\tu8\tppp:1,\ndrivers/net/ethernet/intel/ice/ice_fdir.h-144-\t\trqi:1,\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c=587=static const u32 ice_ptypes_gtpu[] = {\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c-598-/* Packet types for PPPoE /\ndrivers/net/ethernet/intel/ice/ice_flow.c:599:static const u32 ice_ptypes_pppoe[] = {\ndrivers/net/ethernet/intel/ice/ice_flow.c-600-\t0x00000000, 0x00000000, 0x00000000, 0x00000000,\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c=807=static int ice_flow_proc_seg_hdrs(struct ice_flow_prof_params params)\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c-881-\t\t} else if (hdrs \u0026 ICE_FLOW_SEG_HDR_PPPOE) {\ndrivers/net/ethernet/intel/ice/ice_flow.c:882:\t\t\tsrc = (const unsigned long )ice_ptypes_pppoe;\ndrivers/net/ethernet/intel/ice/ice_flow.c-883-\t\t\tbitmap_and(params-\u003eptypes, params-\u003eptypes, src,\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c-885-\t\t} else {\ndrivers/net/ethernet/intel/ice/ice_flow.c:886:\t\t\tsrc = (const unsigned long )ice_ptypes_pppoe;\ndrivers/net/ethernet/intel/ice/ice_flow.c-887-\t\t\tbitmap_andnot(params-\u003eptypes, params-\u003eptypes, src,\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h=233=struct ice_pfcp_hdr {\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-241-\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h:242:struct ice_pppoe_hdr {\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-243-\tu8 rsrvd_ver_type;\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-246-\t__be16 length;\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h:247:\t__be16 ppp_prot_id; /* control and data only /\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-248-};\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h=447=union ice_prot_hdr {\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-458-\tstruct ice_pfcp_hdr pfcp_hdr;\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h:459:\tstruct ice_pppoe_hdr pppoe_hdr;\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-460-\tstruct ice_l2tpv3_sess_hdr l2tpv3_sess_hdr;\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c=1157=ICE_DECLARE_PKT_TEMPLATE(pfcp_session_ipv6) = {\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1185-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1186:ICE_DECLARE_PKT_OFFSETS(pppoe_ipv4_tcp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1187-\t{ ICE_MAC_OFOS,\t\t0 },\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1194-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1195:ICE_DECLARE_PKT_TEMPLATE(pppoe_ipv4_tcp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1196-\t0x00, 0x00, 0x00, 0x00, / ICE_MAC_OFOS 0 /\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1221-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1222:ICE_DECLARE_PKT_OFFSETS(pppoe_ipv4_udp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1223-\t{ ICE_MAC_OFOS,\t\t0 },\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1230-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1231:ICE_DECLARE_PKT_TEMPLATE(pppoe_ipv4_udp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1232-\t0x00, 0x00, 0x00, 0x00, / ICE_MAC_OFOS 0 /\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1254-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1255:ICE_DECLARE_PKT_OFFSETS(pppoe_ipv6_tcp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1256-\t{ ICE_MAC_OFOS,\t\t0 },\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1263-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1264:ICE_DECLARE_PKT_TEMPLATE(pppoe_ipv6_tcp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1265-\t0x00, 0x00, 0x00, 0x00, / ICE_MAC_OFOS 0 /\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1295-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1296:ICE_DECLARE_PKT_OFFSETS(pppoe_ipv6_udp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1297-\t{ ICE_MAC_OFOS,\t\t0 },\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1304-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1305:ICE_DECLARE_PKT_TEMPLATE(pppoe_ipv6_udp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1306-\t0x00, 0x00, 0x00, 0x00, / ICE_MAC_OFOS 0 /\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c=1393=static const struct ice_dummy_pkt_profile ice_dummy_pkt_profiles[] = {\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1420-\tICE_PKT_PROFILE(pfcp_session_ipv4, ICE_PKT_PFCP),\ndrivers/net/ethernet/intel/ice/ice_switch.c:1421:\tICE_PKT_PROFILE(pppoe_ipv6_udp, ICE_PKT_PPPOE \| ICE_PKT_OUTER_IPV6 \|\ndrivers/net/ethernet/intel/ice/ice_switch.c-1422-\t\t\t\t\tICE_PKT_INNER_UDP),\ndrivers/net/ethernet/intel/ice/ice_switch.c:1423:\tICE_PKT_PROFILE(pppoe_ipv6_tcp, ICE_PKT_PPPOE \| ICE_PKT_OUTER_IPV6),\ndrivers/net/ethernet/intel/ice/ice_switch.c:1424:\tICE_PKT_PROFILE(pppoe_ipv4_udp, ICE_PKT_PPPOE \| ICE_PKT_INNER_UDP),\ndrivers/net/ethernet/intel/ice/ice_switch.c:1425:\tICE_PKT_PROFILE(pppoe_ipv4_tcp, ICE_PKT_PPPOE),\ndrivers/net/ethernet/intel/ice/ice_switch.c-1426-\tICE_PKT_PROFILE(gre_ipv6_tcp, ICE_PKT_TUN_NVGRE \| ICE_PKT_INNER_IPV6 \|\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c=5557=ice_find_dummy_packet(struct ice_adv_lkup_elem lkups, u16 lkups_cnt,\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-5614-\t\t\tmatch \|= ICE_PKT_PPPOE;\ndrivers/net/ethernet/intel/ice/ice_switch.c:5615:\t\t\tif (lkups[i].h_u.pppoe_hdr.ppp_prot_id ==\ndrivers/net/ethernet/intel/ice/ice_switch.c-5616-\t\t\t htons(PPP_IPV6))\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c=5641=ice_fill_adv_dummy_packet(struct ice_adv_lkup_elem lkups, u16 lkups_cnt,\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-5724-\t\tcase ICE_PPPOE:\ndrivers/net/ethernet/intel/ice/ice_switch.c:5725:\t\t\tlen = sizeof(struct ice_pppoe_hdr);\ndrivers/net/ethernet/intel/ice/ice_switch.c-5726-\t\t\tbreak;\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c=371=ice_tc_fill_rules(struct ice_hw hw, u32 flags,\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-490-\t\t ICE_TC_FLWR_FIELD_PPP_PROTO)) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:491:\t\tstruct ice_pppoe_hdr vals, masks;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-492-\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:493:\t\tvals = \u0026list[i].h_u.pppoe_hdr;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:494:\t\tmasks = \u0026list[i].m_u.pppoe_hdr;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-495-\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-498-\t\tif (flags \u0026 ICE_TC_FLWR_FIELD_PPPOE_SESSID) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:499:\t\t\tvals-\u003esession_id = headers-\u003epppoe_hdr.session_id;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-500-\t\t\tmasks-\u003esession_id = cpu_to_be16(0xFFFF);\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-503-\t\tif (flags \u0026 ICE_TC_FLWR_FIELD_PPP_PROTO) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:504:\t\t\tvals-\u003eppp_prot_id = headers-\u003epppoe_hdr.ppp_proto;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:505:\t\t\tmasks-\u003eppp_prot_id = cpu_to_be16(0xFFFF);\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-506-\t\t}\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c=1141=ice_add_tc_flower_adv_fltr(struct ice_vsi vsi,\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1289-/\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1290: ice_tc_set_pppoe - Parse PPPoE fields from TC flower filter\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1291- * @match: Pointer to flow match structure\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1293- * @headers: Pointer to outer header fields\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1294: * @returns PPP protocol used in filter (ppp_ses or ppp_disc)\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1295- /\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c=1296=static u16\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1297:ice_tc_set_pppoe(struct flow_match_pppoe match,\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1298-\t\t struct ice_tc_flower_fltr fltr,\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1302-\t\tfltr-\u003eflags \|= ICE_TC_FLWR_FIELD_PPPOE_SESSID;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1303:\t\theaders-\u003epppoe_hdr.session_id = match-\u003ekey-\u003esession_id;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1304-\t}\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1305-\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1306:\tif (match-\u003emask-\u003eppp_proto) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1307-\t\tfltr-\u003eflags \|= ICE_TC_FLWR_FIELD_PPP_PROTO;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1308:\t\theaders-\u003epppoe_hdr.ppp_proto = match-\u003ekey-\u003eppp_proto;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1309-\t}\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c=1637=ice_parse_cls_flower(struct net_device filter_dev, struct ice_vsi *vsi,\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1837-\tif (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_PPPOE)) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1838:\t\tstruct flow_match_pppoe match;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1839-\n\n" }
23/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 29705 output: 34 thoughts: 26 Thoughts: Here's my take on those thoughts: PPTP Configuration Deep Dive Okay, time to circle back and double-check something crucial for this PPTP integration. I need to be absolutely certain I haven't missed any dependencies in the kernel configuration. I should re-examine `drivers/net/ppp/Kconfig` again, meticulously. It’s too easy to overlook something in these nested configurations, especially with the potential for interactions between different network subsystems. I want to build a bulletproof understanding, so a fresh look is essential before I proceed any further.
24/2	2026/09/02 16:35	tool	read-file	0m Args: { "File": "drivers/net/ppp/Kconfig", "FirstLine": 1, "LineCount": 40 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0-only\n 2:\t#\n 3:\t# PPP network device configuration\n 4:\t#\n 5:\t\n 6:\tconfig PPP\n 7:\t\ttristate \"PPP (point-to-point protocol) support\"\n 8:\t\tselect SLHC\n 9:\t\thelp\n 10:\t\t PPP (Point to Point Protocol) is a newer and better SLIP. It serves\n 11:\t\t the same purpose: sending Internet traffic over telephone (and other\n 12:\t\t serial) lines. Ask your access provider if they support it, because\n 13:\t\t otherwise you can't use it; most Internet access providers these\n 14:\t\t days support PPP rather than SLIP.\n 15:\t\n 16:\t\t To use PPP, you need an additional program called pppd, available at\n 17:\t\t \u003chttps://ppp.samba.org\u003e. Make sure that you have the version of pppd\n 18:\t\t recommended in \u003cfile:Documentation/Changes\u003e.\n 19:\t\t The PPP option enlarges your kernel by about 16 KB.\n 20:\t\n 21:\t\t There are actually two versions of PPP: the traditional PPP for\n 22:\t\t asynchronous lines, such as regular analog phone lines, and\n 23:\t\t synchronous PPP which can be used over digital ISDN lines for\n 24:\t\t example. If you want to use PPP over phone lines or other\n 25:\t\t asynchronous serial lines, you need to say Y (or M) here and also to\n 26:\t\t the next option, \"PPP support for async serial ports\". For PPP over\n 27:\t\t synchronous lines, you should say Y (or M) here and to \"Support\n 28:\t\t synchronous PPP\", below.\n 29:\t\n 30:\t\t If you said Y to \"Version information on all symbols\" above, then\n 31:\t\t you cannot compile the PPP driver into the kernel; you can then only\n 32:\t\t compile it as a module. To compile this driver as a module, choose M\n 33:\t\t here. The module will be called ppp_generic.\n 34:\t\n 35:\tif PPP\n 36:\t\n 37:\tconfig PPP_BSDCOMP\n 38:\t\ttristate \"PPP BSD-Compress compression\"\n 39:\t\thelp\n 40:\t\t Support for the BSD-Compress compression method for PPP, which uses\n" }
25/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 30515 output: 35 thoughts: 148 Thoughts: My Analysis of PPTP Configuration Options Okay, let's break this down. From what I'm seeing, `PPTP` is nested within an `if PPP ... endif` block. This tells me that `CONFIG_PPP` is a prerequisite for enabling the `PPTP` option, and therefore so is `CONFIG_PPTP`, and also `CONFIG_NET_IPGRE_DEMUX`, which `PPTP` relies upon. And further, it looks like `PPTP` also automatically selects `PPPOX` via `CONFIG_PPPOX`. Now, I need to confirm whether `CONFIG_INET` or any other core network configuration elements are essential here. Let's see... looking at the `net/ipv4/Kconfig` file, `NET_IPGRE_DEMUX` – which is required for PPTP – depends on `INET`. Given that `INET` is fundamentally standard networking functionality, that makes perfect sense. I will now double-check `net/ipv4/Kconfig` directly for any other `NET_IPGRE_DEMUX` dependencies to complete the picture.
26/2	2026/09/02 16:35	tool	read-file	0m Args: { "File": "net/ipv4/Kconfig", "FirstLine": 178, "LineCount": 15 } Results: { "Contents": " 178:\t\t want). Most people won't need this and can say N.\n 179:\t\n 180:\tconfig NET_IPGRE_DEMUX\n 181:\t\ttristate \"IP: GRE demultiplexer\"\n 182:\t\thelp\n 183:\t\t This is helper module to demultiplex GRE packets on GRE version field criteria.\n 184:\t\t Required by ip_gre and pptp modules.\n 185:\t\n 186:\tconfig NET_IP_TUNNEL\n 187:\t\ttristate\n 188:\t\tselect DST_CACHE\n 189:\t\tselect GRO_CELLS\n 190:\t\tdefault n\n 191:\t\n 192:\tconfig NET_IPGRE\n" }
27/2	2026/09/02 16:35	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 31145 output: 176 thoughts: 469 Thoughts: Fuzzing Verdict: Confirmed Okay, let's break this down. First, I wanted to confirm the `NET_IPGRE_DEMUX` config option. It's not directly dependent on anything else, but it is nested within `net/ipv4/Kconfig` under `menuconfig INET`, which is as expected. Next, I looked at the `FocusSymbols`. The analysis pointed to these key functions: `pptp_rcv_core`, `pptp_rcv`, `pptp_connect`, `pptp_bind`, `pptp_create`, and `pptp_xmit`. I had to quickly double-check if any of these were static or inlined, since that would affect fuzzing. I confirmed that `pptp_rcv_core` and `pptp_rcv` are static, and the others, `pptp_connect`, `pptp_bind`, `pptp_create`, `pptp_xmit`, are used via function pointers in ops structures. Because of this, the compiler won't be inlining them. This means the list of non-inlined functions to target for fuzzing is: `pptp_rcv_core`, `pptp_rcv`, `pptp_create`, `pptp_connect`, and `pptp_bind`. I then made sure the `EnableConfigs` list matched the requirements. I've verified that `PPTP`, `PPP`, and `NET_IPGRE_DEMUX` are the correct config flags. Finally, I reviewed the prompt requirements: the `WorthFuzzing` flag is true, since these changes have a functional impact worth fuzzing. I have a list of non-hot-path kernel functions to focus fuzzing on, and the required enable configs. Everything matches. The data is validated. Let's call `set-results`.
28/2	2026/09/02 16:35	tool	set-results	0m Args: { "EnableConfigs": [ "PPTP", "PPP", "NET_IPGRE_DEMUX" ], "FocusSymbols": [ "pptp_rcv_core", "pptp_rcv", "pptp_create", "pptp_connect", "pptp_bind" ], "Reasoning": "The patch modifies packet reception parsing and bounds checking logic in pptp_rcv_core() within the PPTP network protocol driver (drivers/net/ppp/pptp.c), ensuring payload availability checks and pskb_may_pull() calls precede header dereferencing to prevent out-of-bounds reads on truncated packets. This is reachable in standard virtualized environments via AF_PPPOX sockets and GRE packet delivery.", "WorthFuzzing": true } Results: { "EnableConfigs": [ "PPTP", "PPP", "NET_IPGRE_DEMUX" ], "FocusSymbols": [ "pptp_rcv_core", "pptp_rcv", "pptp_create", "pptp_connect", "pptp_bind" ], "Reasoning": "The patch modifies packet reception parsing and bounds checking logic in pptp_rcv_core() within the PPTP network protocol driver (drivers/net/ppp/pptp.c), ensuring payload availability checks and pskb_may_pull() calls precede header dereferencing to prevent out-of-bounds reads on truncated packets. This is reachable in standard virtualized environments via AF_PPPOX sockets and GRE packet delivery.", "WorthFuzzing": true }
29/1	2026/09/02 16:35	action	If	0m Args: { "WorthFuzzing": true } Results: null
30/2	2026/09/02 16:35	agent	kmsan-evaluator	0m Model: core Args: null Results: { "KMSANReasoning": "The patch addresses bounds checking and skb pull operations in the PPTP receive path (drivers/net/ppp/pptp.c). Specifically, it ensures that adequate payload bytes are available and pulled into the skb linear area before indexing into skb payload offsets (payload[0] through payload[4] and skb-\u003edata[0] through skb-\u003edata[1]).\n\nThese changes prevent out-of-bounds (OOB) memory reads on truncated or malformed network packets. OOB reads and invalid skb buffer dereferences are directly detected by standard KASAN builds. The patch does not introduce new heap/stack allocations, does not copy kernel memory to user space, and does not alter control flow based on uninitialized memory. 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: For your convenience, here is the diff of the changes: commit 215595925f298eef5f22d9c7d28b35122da02c8f Author: syz-cluster <triage@syzkaller.com> Date: Wed Sep 2 16:35:00 2026 +0000 syz-cluster: applied patch under review diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c index a797a0606f6b4..4fb94a455c574 100644 --- a/drivers/net/ppp/pptp.c +++ b/drivers/net/ppp/pptp.c @@ -275,6 +275,7 @@ static int pptp_rcv_core(struct sock sk, struct sk_buff skb) struct pppox_sock po = pppox_sk(sk); struct pptp_opt opt = &po->proto.pptp; int headersize, payload_len, seq; + unsigned int payload_avail; __u8 payload; struct pptp_gre_header header; @@ -314,23 +315,34 @@ static int pptp_rcv_core(struct sock sk, struct sk_buff skb) if (!pskb_may_pull(skb, headersize + payload_len)) goto drop; - payload = skb->data + headersize; + payload_avail = skb->len - headersize; /* check for expected sequence number / if (seq < opt->seq_recv + 1 \|\| WRAPPED(opt->seq_recv, seq)) { - if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) && - (PPP_PROTOCOL(payload) == PPP_LCP) && - ((payload[4] == PPP_LCP_ECHOREQ) \|\| (payload[4] == PPP_LCP_ECHOREP))) - goto allow_packet; + if (payload_avail >= PPP_HDRLEN + 1) { + if (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1)) + goto drop; + + payload = skb->data + headersize; + if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI && + PPP_PROTOCOL(payload) == PPP_LCP && + (payload[4] == PPP_LCP_ECHOREQ \|\| payload[4] == PPP_LCP_ECHOREP)) + goto allow_packet; + } } else { opt->seq_recv = seq; allow_packet: skb_pull(skb, headersize); - if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) { - / chop off address/control / - if (skb->len < 3) + if (payload_avail >= 2) { + if (!pskb_may_pull(skb, 2)) goto drop; - skb_pull(skb, 2); + + if (skb->data[0] == PPP_ALLSTATIONS && skb->data[1] == PPP_UI) { + / chop off address/control */ + if (skb->len < 3) + goto drop; + skb_pull(skb, 2); + } } skb->ip_summed = CHECKSUM_NONE;
31/3	2026/09/02 16:35	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 2699 output: 38 thoughts: 132 Thoughts: Evaluating the Necessity of KMSAN Fuzzing for a PPPTP Patch Okay, so I need to decide if this patch in `drivers/net/ppp/pptp.c` warrants a separate KMSAN fuzzing session, beyond the usual KASAN checks. Let's break this down systematically. It's really just software defense and kernel patch review. The severity here is pretty low – just the usual code review and picking the right sanitization tool. No immediate fire drills. I should examine the patch itself first, and then really dig into the surrounding code in `drivers/net/ppp/pptp.c`. I'll probably start with a quick glance, but if anything looks even slightly suspicious, I'll definitely dive deeper, using `read-file` or `grepper` to get a clearer picture of the function of the code around this patch and the variables being used. This isn't high-stakes, but I want to be thorough. It's all about making an informed decision about allocating resources.
32/3	2026/09/02 16:36	tool	read-file	0m Args: { "File": "drivers/net/ppp/pptp.c", "FirstLine": 270, "LineCount": 90 } Results: { "Contents": " 270:\t\treturn 1;\n 271:\t}\n 272:\t\n 273:\tstatic int pptp_rcv_core(struct sock sk, struct sk_buff skb)\n 274:\t{\n 275:\t\tstruct pppox_sock po = pppox_sk(sk);\n 276:\t\tstruct pptp_opt opt = \u0026po-\u003eproto.pptp;\n 277:\t\tint headersize, payload_len, seq;\n 278:\t\tunsigned int payload_avail;\n 279:\t\t__u8 payload;\n 280:\t\tstruct pptp_gre_header header;\n 281:\t\n 282:\t\tif (!(sk-\u003esk_state \u0026 PPPOX_CONNECTED))\n 283:\t\t\tgoto drop;\n 284:\t\n 285:\t\theader = (struct pptp_gre_header )(skb-\u003edata);\n 286:\t\theadersize = sizeof(header);\n 287:\t\n 288:\t\t/* test if acknowledgement present /\n 289:\t\tif (GRE_IS_ACK(header-\u003egre_hd.flags)) {\n 290:\t\t\t__u32 ack;\n 291:\t\n 292:\t\t\tif (!pskb_may_pull(skb, headersize))\n 293:\t\t\t\tgoto drop;\n 294:\t\t\theader = (struct pptp_gre_header )(skb-\u003edata);\n 295:\t\n 296:\t\t\t/* ack in different place if S = 0 /\n 297:\t\t\tack = GRE_IS_SEQ(header-\u003egre_hd.flags) ? ntohl(header-\u003eack) :\n 298:\t\t\t\t\t\t\t\t ntohl(header-\u003eseq);\n 299:\t\t\tif (ack \u003e opt-\u003eack_recv)\n 300:\t\t\t\topt-\u003eack_recv = ack;\n 301:\t\t\t/ also handle sequence number wrap-around /\n 302:\t\t\tif (WRAPPED(ack, opt-\u003eack_recv))\n 303:\t\t\t\topt-\u003eack_recv = ack;\n 304:\t\t} else {\n 305:\t\t\theadersize -= sizeof(header-\u003eack);\n 306:\t\t}\n 307:\t\t/ test if payload present /\n 308:\t\tif (!GRE_IS_SEQ(header-\u003egre_hd.flags))\n 309:\t\t\tgoto drop;\n 310:\t\n 311:\t\tpayload_len = ntohs(header-\u003epayload_len);\n 312:\t\tseq = ntohl(header-\u003eseq);\n 313:\t\n 314:\t\t/ check for incomplete packet (length smaller than expected) /\n 315:\t\tif (!pskb_may_pull(skb, headersize + payload_len))\n 316:\t\t\tgoto drop;\n 317:\t\n 318:\t\tpayload_avail = skb-\u003elen - headersize;\n 319:\t\t/ check for expected sequence number /\n 320:\t\tif (seq \u003c opt-\u003eseq_recv + 1 \|\| WRAPPED(opt-\u003eseq_recv, seq)) {\n 321:\t\t\tif (payload_avail \u003e= PPP_HDRLEN + 1) {\n 322:\t\t\t\tif (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1))\n 323:\t\t\t\t\tgoto drop;\n 324:\t\n 325:\t\t\t\tpayload = skb-\u003edata + headersize;\n 326:\t\t\t\tif (payload[0] == PPP_ALLSTATIONS \u0026\u0026 payload[1] == PPP_UI \u0026\u0026\n 327:\t\t\t\t PPP_PROTOCOL(payload) == PPP_LCP \u0026\u0026\n 328:\t\t\t\t (payload[4] == PPP_LCP_ECHOREQ \|\| payload[4] == PPP_LCP_ECHOREP))\n 329:\t\t\t\t\tgoto allow_packet;\n 330:\t\t\t}\n 331:\t\t} else {\n 332:\t\t\topt-\u003eseq_recv = seq;\n 333:\tallow_packet:\n 334:\t\t\tskb_pull(skb, headersize);\n 335:\t\n 336:\t\t\tif (payload_avail \u003e= 2) {\n 337:\t\t\t\tif (!pskb_may_pull(skb, 2))\n 338:\t\t\t\t\tgoto drop;\n 339:\t\n 340:\t\t\t\tif (skb-\u003edata[0] == PPP_ALLSTATIONS \u0026\u0026 skb-\u003edata[1] == PPP_UI) {\n 341:\t\t\t\t\t/ chop off address/control /\n 342:\t\t\t\t\tif (skb-\u003elen \u003c 3)\n 343:\t\t\t\t\t\tgoto drop;\n 344:\t\t\t\t\tskb_pull(skb, 2);\n 345:\t\t\t\t}\n 346:\t\t\t}\n 347:\t\n 348:\t\t\tskb-\u003eip_summed = CHECKSUM_NONE;\n 349:\t\t\tskb_set_network_header(skb, skb-\u003ehead-skb-\u003edata);\n 350:\t\t\tppp_input(\u0026po-\u003echan, skb);\n 351:\t\n 352:\t\t\treturn NET_RX_SUCCESS;\n 353:\t\t}\n 354:\tdrop:\n 355:\t\tkfree_skb(skb);\n 356:\t\treturn NET_RX_DROP;\n 357:\t}\n 358:\t\n 359:\tstatic int pptp_rcv(struct sk_buff skb)\n" }
33/3	2026/09/02 16:36	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 4487 output: 191 thoughts: 1096 Thoughts: Analysis of the PPTP Patch and Sanitizer Selection Okay, let's break this down. My initial focus is on the patch within `pptp_rcv_core()` and the bug it's designed to fix. Previously, there was a significant vulnerability: if the incoming packet payload was small, particularly with zero or minimal data, the checks were insufficient. `pskb_may_pull` might succeed, even though accessing `payload[0]` through `payload[4]` would lead to an out-of-bounds read from the skb's linear buffer or unpulled skb data. This is textbook out-of-bounds memory access. The same issue also occurred if `skb_pull` was called, then `payload[0]` was accessed. The patch addresses this directly. The fix involves two key changes: First, rigorous bounds checks are introduced before any access to the `payload` data. This employs a combination of `payload_avail` and more precise calls to `pskb_may_pull` with calculated lengths (`headersize + PPP_HDRLEN + 1`). Second, access to the `skb->data` pointer after `skb_pull` occurs. Now, let's evaluate which sanitizer is most relevant. Given the nature of the bug, an out-of-bounds read within the skb buffer, the choice is fairly clear. KMSAN is primarily designed to detect uninitialized memory reads. I need to determine if any of those conditions apply here. 1. Kernel data exposed to userspace? No. This is incoming packet processing. 2. Conditional logic based on uninitialized variables? No. All variables used (payload\_avail, seq, headersize, etc.) are properly initialized. 3. Complex data structures with initialization issues? No, the code is relatively straightforward. 4. Bounds checks leading to uninitialized memory exposure? No. The data coming from the network is packet data, initialized upon reception. The bugs are clearly buffer bounds issues – KASAN territory. KMSAN would be irrelevant. KASAN vs. KMSAN: * KASAN: Detects a wide array of memory safety issues, including out-of-bounds access (slab, global, stack), and use-after-free conditions. These are precisely the types of issues we're addressing with the patch's bounds checks. * KMSAN: Targets the detection of uninitialized memory reads. This is not the issue here. In short, the patch modifies packet parsing in the PPTP network receive path, adding crucial length checks (`pskb_may_pull` and `payload_avail >= ...`) before indexing into the network skb payload buffers. These additions directly address the vulnerability of out-of-bounds buffer reads on short or non-linear skb packets. Since there's no uninitialized kernel memory involved or any of the usual KMSAN concerns, KASAN is the correct sanitizer here. No KMSAN fuzzing is necessary. Therefore, I'm confident in setting `NeedsKMSAN` to `false`. I need to now ensure that my analysis and reasoning are clear.
34/3	2026/09/02 16:36	tool	set-results	0m Args: { "KMSANReasoning": "The patch addresses bounds checking and skb pull operations in the PPTP receive path (drivers/net/ppp/pptp.c). Specifically, it ensures that adequate payload bytes are available and pulled into the skb linear area before indexing into skb payload offsets (payload[0] through payload[4] and skb-\u003edata[0] through skb-\u003edata[1]).\n\nThese changes prevent out-of-bounds (OOB) memory reads on truncated or malformed network packets. OOB reads and invalid skb buffer dereferences are directly detected by standard KASAN builds. The patch does not introduce new heap/stack allocations, does not copy kernel memory to user space, and does not alter control flow based on uninitialized memory. Therefore, a dedicated KMSAN session is not required.", "NeedsKMSAN": false } Results: { "KMSANReasoning": "The patch addresses bounds checking and skb pull operations in the PPTP receive path (drivers/net/ppp/pptp.c). Specifically, it ensures that adequate payload bytes are available and pulled into the skb linear area before indexing into skb payload offsets (payload[0] through payload[4] and skb-\u003edata[0] through skb-\u003edata[1]).\n\nThese changes prevent out-of-bounds (OOB) memory reads on truncated or malformed network packets. OOB reads and invalid skb buffer dereferences are directly detected by standard KASAN builds. The patch does not introduce new heap/stack allocations, does not copy kernel memory to user space, and does not alter control flow based on uninitialized memory. Therefore, a dedicated KMSAN session is not required.", "NeedsKMSAN": false }

{
  "EnableConfigs": [
    "PPTP",
    "PPP",
    "NET_IPGRE_DEMUX"
  ],
  "FocusSymbols": [
    "pptp_rcv_core",
    "pptp_rcv",
    "pptp_create",
    "pptp_connect",
    "pptp_bind"
  ],
  "KMSANReasoning": "The patch addresses bounds checking and skb pull operations in the PPTP receive path (drivers/net/ppp/pptp.c). Specifically, it ensures that adequate payload bytes are available and pulled into the skb linear area before indexing into skb payload offsets (payload[0] through payload[4] and skb-\u003edata[0] through skb-\u003edata[1]).\n\nThese changes prevent out-of-bounds (OOB) memory reads on truncated or malformed network packets. OOB reads and invalid skb buffer dereferences are directly detected by standard KASAN builds. The patch does not introduce new heap/stack allocations, does not copy kernel memory to user space, and does not alter control flow based on uninitialized memory. Therefore, a dedicated KMSAN session is not required.",
  "NeedsKMSAN": false,
  "Reasoning": "The patch modifies packet reception parsing and bounds checking logic in pptp_rcv_core() within the PPTP network protocol driver (drivers/net/ppp/pptp.c), ensuring payload availability checks and pskb_may_pull() calls precede header dereferencing to prevent out-of-bounds reads on truncated packets. This is reachable in standard virtualized environments via AF_PPPOX sockets and GRE packet delivery.",
  "WorthFuzzing": true
}

{
  "PatchDiff": "commit 215595925f298eef5f22d9c7d28b35122da02c8f\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Wed Sep 2 16:35:00 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c\nindex a797a0606f6b4..4fb94a455c574 100644\n--- a/drivers/net/ppp/pptp.c\n+++ b/drivers/net/ppp/pptp.c\n@@ -275,6 +275,7 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)\n \tstruct pppox_sock *po = pppox_sk(sk);\n \tstruct pptp_opt *opt = \u0026po-\u003eproto.pptp;\n \tint headersize, payload_len, seq;\n+\tunsigned int payload_avail;\n \t__u8 *payload;\n \tstruct pptp_gre_header *header;\n \n@@ -314,23 +315,34 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)\n \tif (!pskb_may_pull(skb, headersize + payload_len))\n \t\tgoto drop;\n \n-\tpayload = skb-\u003edata + headersize;\n+\tpayload_avail = skb-\u003elen - headersize;\n \t/* check for expected sequence number */\n \tif (seq \u003c opt-\u003eseq_recv + 1 || WRAPPED(opt-\u003eseq_recv, seq)) {\n-\t\tif ((payload[0] == PPP_ALLSTATIONS) \u0026\u0026 (payload[1] == PPP_UI) \u0026\u0026\n-\t\t\t\t(PPP_PROTOCOL(payload) == PPP_LCP) \u0026\u0026\n-\t\t\t\t((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP)))\n-\t\t\tgoto allow_packet;\n+\t\tif (payload_avail \u003e= PPP_HDRLEN + 1) {\n+\t\t\tif (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1))\n+\t\t\t\tgoto drop;\n+\n+\t\t\tpayload = skb-\u003edata + headersize;\n+\t\t\tif (payload[0] == PPP_ALLSTATIONS \u0026\u0026 payload[1] == PPP_UI \u0026\u0026\n+\t\t\t    PPP_PROTOCOL(payload) == PPP_LCP \u0026\u0026\n+\t\t\t    (payload[4] == PPP_LCP_ECHOREQ || payload[4] == PPP_LCP_ECHOREP))\n+\t\t\t\tgoto allow_packet;\n+\t\t}\n \t} else {\n \t\topt-\u003eseq_recv = seq;\n allow_packet:\n \t\tskb_pull(skb, headersize);\n \n-\t\tif (payload[0] == PPP_ALLSTATIONS \u0026\u0026 payload[1] == PPP_UI) {\n-\t\t\t/* chop off address/control */\n-\t\t\tif (skb-\u003elen \u003c 3)\n+\t\tif (payload_avail \u003e= 2) {\n+\t\t\tif (!pskb_may_pull(skb, 2))\n \t\t\t\tgoto drop;\n-\t\t\tskb_pull(skb, 2);\n+\n+\t\t\tif (skb-\u003edata[0] == PPP_ALLSTATIONS \u0026\u0026 skb-\u003edata[1] == PPP_UI) {\n+\t\t\t\t/* chop off address/control */\n+\t\t\t\tif (skb-\u003elen \u003c 3)\n+\t\t\t\t\tgoto drop;\n+\t\t\t\tskb_pull(skb, 2);\n+\t\t\t}\n \t\t}\n \n \t\tskb-\u003eip_summed = CHECKSUM_NONE;\n"
}

{
  "EnableConfigs": [
    "PPTP",
    "PPP",
    "NET_IPGRE_DEMUX"
  ],
  "FocusSymbols": [
    "pptp_rcv_core",
    "pptp_rcv",
    "pptp_create",
    "pptp_connect",
    "pptp_bind"
  ],
  "Reasoning": "The patch modifies packet reception parsing and bounds checking logic in pptp_rcv_core() within the PPTP network protocol driver (drivers/net/ppp/pptp.c), ensuring payload availability checks and pskb_may_pull() calls precede header dereferencing to prevent out-of-bounds reads on truncated packets. This is reachable in standard virtualized environments via AF_PPPOX sockets and GRE packet delivery.",
  "WorthFuzzing": true
}

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.

For your convenience, here is the diff of the changes:
commit 215595925f298eef5f22d9c7d28b35122da02c8f
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Sep 2 16:35:00 2026 +0000

    syz-cluster: applied patch under review

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index a797a0606f6b4..4fb94a455c574 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -275,6 +275,7 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
 	struct pppox_sock *po = pppox_sk(sk);
 	struct pptp_opt *opt = &po->proto.pptp;
 	int headersize, payload_len, seq;
+	unsigned int payload_avail;
 	__u8 *payload;
 	struct pptp_gre_header *header;
 
@@ -314,23 +315,34 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
 	if (!pskb_may_pull(skb, headersize + payload_len))
 		goto drop;
 
-	payload = skb->data + headersize;
+	payload_avail = skb->len - headersize;
 	/* check for expected sequence number */
 	if (seq < opt->seq_recv + 1 || WRAPPED(opt->seq_recv, seq)) {
-		if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) &&
-				(PPP_PROTOCOL(payload) == PPP_LCP) &&
-				((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP)))
-			goto allow_packet;
+		if (payload_avail >= PPP_HDRLEN + 1) {
+			if (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1))
+				goto drop;
+
+			payload = skb->data + headersize;
+			if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI &&
+			    PPP_PROTOCOL(payload) == PPP_LCP &&
+			    (payload[4] == PPP_LCP_ECHOREQ || payload[4] == PPP_LCP_ECHOREP))
+				goto allow_packet;
+		}
 	} else {
 		opt->seq_recv = seq;
 allow_packet:
 		skb_pull(skb, headersize);
 
-		if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) {
-			/* chop off address/control */
-			if (skb->len < 3)
+		if (payload_avail >= 2) {
+			if (!pskb_may_pull(skb, 2))
 				goto drop;
-			skb_pull(skb, 2);
+
+			if (skb->data[0] == PPP_ALLSTATIONS && skb->data[1] == PPP_UI) {
+				/* chop off address/control */
+				if (skb->len < 3)
+					goto drop;
+				skb_pull(skb, 2);
+			}
 		}
 
 		skb->ip_summed = CHECKSUM_NONE;

							input: 2702
							output: 39
							thoughts: 96

Okay, here's my summary, tailored as requested:

**Digging into that PPTP Patch**

Alright, let's get down to brass tacks. I need to understand this patch, and my initial focus is on the `drivers/net/ppp/pptp.c` file. That's where the core changes seem to be. Specifically, I'm zeroing in on the `pptp_rcv_core` function. I'll need to dissect that to grasp the impact of the patch.

Beyond the code itself, I should make sure there aren't any sneaky interactions. I'll need to check the relevant Kconfig options and symbol definitions within the `drivers/net/ppp/` directory, including that `pptp.c` file. I need to know how this modification interacts with the rest of the PPP stack, and how it might be enabled/disabled.

Finally, I'll leverage the tools at my disposal. Grepping through the codebase or strategically using `read-file` to zero in on relevant code sections, dependencies, or potential side effects is the next logical step. It's time to get a more comprehensive understanding of the changes and how they fit into the bigger picture.

{
  "File": "drivers/net/ppp/pptp.c",
  "FirstLine": 260,
  "LineCount": 100
}

{
  "Contents": " 260:\t\tip_select_ident(net, skb, NULL);\n 261:\t\tip_send_check(iph);\n 262:\t\n 263:\t\tip_local_out(net, skb-\u003esk, skb);\n 264:\t\treturn 1;\n 265:\t\n 266:\ttx_error:\n 267:\t\tip_rt_put(rt);\n 268:\ttx_drop:\n 269:\t\tkfree_skb(skb);\n 270:\t\treturn 1;\n 271:\t}\n 272:\t\n 273:\tstatic int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)\n 274:\t{\n 275:\t\tstruct pppox_sock *po = pppox_sk(sk);\n 276:\t\tstruct pptp_opt *opt = \u0026po-\u003eproto.pptp;\n 277:\t\tint headersize, payload_len, seq;\n 278:\t\tunsigned int payload_avail;\n 279:\t\t__u8 *payload;\n 280:\t\tstruct pptp_gre_header *header;\n 281:\t\n 282:\t\tif (!(sk-\u003esk_state \u0026 PPPOX_CONNECTED))\n 283:\t\t\tgoto drop;\n 284:\t\n 285:\t\theader = (struct pptp_gre_header *)(skb-\u003edata);\n 286:\t\theadersize  = sizeof(*header);\n 287:\t\n 288:\t\t/* test if acknowledgement present */\n 289:\t\tif (GRE_IS_ACK(header-\u003egre_hd.flags)) {\n 290:\t\t\t__u32 ack;\n 291:\t\n 292:\t\t\tif (!pskb_may_pull(skb, headersize))\n 293:\t\t\t\tgoto drop;\n 294:\t\t\theader = (struct pptp_gre_header *)(skb-\u003edata);\n 295:\t\n 296:\t\t\t/* ack in different place if S = 0 */\n 297:\t\t\tack = GRE_IS_SEQ(header-\u003egre_hd.flags) ? ntohl(header-\u003eack) :\n 298:\t\t\t\t\t\t\t\t ntohl(header-\u003eseq);\n 299:\t\t\tif (ack \u003e opt-\u003eack_recv)\n 300:\t\t\t\topt-\u003eack_recv = ack;\n 301:\t\t\t/* also handle sequence number wrap-around  */\n 302:\t\t\tif (WRAPPED(ack, opt-\u003eack_recv))\n 303:\t\t\t\topt-\u003eack_recv = ack;\n 304:\t\t} else {\n 305:\t\t\theadersize -= sizeof(header-\u003eack);\n 306:\t\t}\n 307:\t\t/* test if payload present */\n 308:\t\tif (!GRE_IS_SEQ(header-\u003egre_hd.flags))\n 309:\t\t\tgoto drop;\n 310:\t\n 311:\t\tpayload_len = ntohs(header-\u003epayload_len);\n 312:\t\tseq         = ntohl(header-\u003eseq);\n 313:\t\n 314:\t\t/* check for incomplete packet (length smaller than expected) */\n 315:\t\tif (!pskb_may_pull(skb, headersize + payload_len))\n 316:\t\t\tgoto drop;\n 317:\t\n 318:\t\tpayload_avail = skb-\u003elen - headersize;\n 319:\t\t/* check for expected sequence number */\n 320:\t\tif (seq \u003c opt-\u003eseq_recv + 1 || WRAPPED(opt-\u003eseq_recv, seq)) {\n 321:\t\t\tif (payload_avail \u003e= PPP_HDRLEN + 1) {\n 322:\t\t\t\tif (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1))\n 323:\t\t\t\t\tgoto drop;\n 324:\t\n 325:\t\t\t\tpayload = skb-\u003edata + headersize;\n 326:\t\t\t\tif (payload[0] == PPP_ALLSTATIONS \u0026\u0026 payload[1] == PPP_UI \u0026\u0026\n 327:\t\t\t\t    PPP_PROTOCOL(payload) == PPP_LCP \u0026\u0026\n 328:\t\t\t\t    (payload[4] == PPP_LCP_ECHOREQ || payload[4] == PPP_LCP_ECHOREP))\n 329:\t\t\t\t\tgoto allow_packet;\n 330:\t\t\t}\n 331:\t\t} else {\n 332:\t\t\topt-\u003eseq_recv = seq;\n 333:\tallow_packet:\n 334:\t\t\tskb_pull(skb, headersize);\n 335:\t\n 336:\t\t\tif (payload_avail \u003e= 2) {\n 337:\t\t\t\tif (!pskb_may_pull(skb, 2))\n 338:\t\t\t\t\tgoto drop;\n 339:\t\n 340:\t\t\t\tif (skb-\u003edata[0] == PPP_ALLSTATIONS \u0026\u0026 skb-\u003edata[1] == PPP_UI) {\n 341:\t\t\t\t\t/* chop off address/control */\n 342:\t\t\t\t\tif (skb-\u003elen \u003c 3)\n 343:\t\t\t\t\t\tgoto drop;\n 344:\t\t\t\t\tskb_pull(skb, 2);\n 345:\t\t\t\t}\n 346:\t\t\t}\n 347:\t\n 348:\t\t\tskb-\u003eip_summed = CHECKSUM_NONE;\n 349:\t\t\tskb_set_network_header(skb, skb-\u003ehead-skb-\u003edata);\n 350:\t\t\tppp_input(\u0026po-\u003echan, skb);\n 351:\t\n 352:\t\t\treturn NET_RX_SUCCESS;\n 353:\t\t}\n 354:\tdrop:\n 355:\t\tkfree_skb(skb);\n 356:\t\treturn NET_RX_DROP;\n 357:\t}\n 358:\t\n 359:\tstatic int pptp_rcv(struct sk_buff *skb)\n"
}

							input: 4632
							output: 29
							thoughts: 20

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Diving into the PPP Networking Landscape**

Alright, let's get down to brass tacks. I'm focusing on the PPP networking configuration, specifically within the kernel's driver infrastructure. I need to understand the specifics of Point-to-Point Protocol (PPP) configuration. I'm thinking I'll start by digging into the Kconfig files, starting with the `drivers/net/ppp/` directory. That's the logical place to begin, to figure out where PPP support, and by extension, the PPTP (Point-to-Point Tunneling Protocol) options are defined. I need to quickly identify the relevant configuration symbols and dependencies. From there, I can determine the build options and understand how PPTP is integrated and possibly even, the reasoning behind the design.

{
  "Expression": "pptp\\.o",
  "PathPrefix": "drivers/net/ppp"
}

{
  "Output": "drivers/net/ppp/Makefile=13=obj-$(CONFIG_PPPOE) += pppoe.o\ndrivers/net/ppp/Makefile:14:obj-$(CONFIG_PPTP) += pptp.o\n"
}

							input: 4926
							output: 28
							thoughts: 21

Here's my thought process, as if I were considering this myself:

**Investigating the PPTP Configuration in the Kernel**

Okay, so I need to figure out where the `CONFIG_PPTP` option resides in the kernel's build configuration. My first instinct, as an experienced kernel developer, is to go directly to the source. The likely place to start is the PPP networking code, so I'll check inside the `drivers/net/ppp` directory. More specifically, I know that configuration options are typically defined in `Kconfig` files. Therefore, my initial target will be `drivers/net/ppp/Kconfig`. That file should contain the definition for `CONFIG_PPTP` and tell me what dependencies it has. That's the logical starting point for understanding its configuration.

{
  "Expression": "config PPTP",
  "PathPrefix": "drivers/net/ppp"
}

{
  "Output": "drivers/net/ppp/Kconfig=153=config PPPOE_HASH_BITS\n--\ndrivers/net/ppp/Kconfig-160-\ndrivers/net/ppp/Kconfig:161:config PPTP\ndrivers/net/ppp/Kconfig-162-\ttristate \"PPP over IPv4 (PPTP)\"\n"
}

							input: 5236
							output: 36
							thoughts: 11

Okay, here's my take on those thoughts, tailored for an expert audience:

**Analyzing the PPTP Kconfig**

Alright, let's dive in. My immediate thought is, "Let's crack open the Kconfig files related to PPTP." I need to get a clear picture of how PPTP is configured within the kernel build system. I'm assuming we're dealing with a specific kernel version or configuration context, so I'm focusing my mental energy on that. I'll be looking for the dependencies, options, defaults, and potentially any tristate logic associated with the PPTP support. Specifically, I'll be assessing how PPTP support interacts with other network components and security features. My goal is a full picture of PPTP's build time integration.

{
  "File": "drivers/net/ppp/Kconfig",
  "FirstLine": 150,
  "LineCount": 40
}

{
  "Contents": " 150:\t\n 151:\tendchoice\n 152:\t\n 153:\tconfig PPPOE_HASH_BITS\n 154:\t\tint\n 155:\t\tdefault 1 if PPPOE_HASH_BITS_1\n 156:\t\tdefault 2 if PPPOE_HASH_BITS_2\n 157:\t\tdefault 4 if PPPOE_HASH_BITS_4\n 158:\t\tdefault 8 if PPPOE_HASH_BITS_8\n 159:\t\tdefault 4\n 160:\t\n 161:\tconfig PPTP\n 162:\t\ttristate \"PPP over IPv4 (PPTP)\"\n 163:\t\tdepends on NET_IPGRE_DEMUX\n 164:\t\tselect PPPOX\n 165:\t\thelp\n 166:\t\t  Support for PPP over IPv4.(Point-to-Point Tunneling Protocol)\n 167:\t\n 168:\t\t  This driver requires pppd plugin to work in client mode or\n 169:\t\t  modified pptpd (poptop) to work in server mode.\n 170:\t\t  See http://accel-pptp.sourceforge.net/ for information how to\n 171:\t\t  utilize this module.\n 172:\t\n 173:\tconfig PPPOL2TP\n 174:\t\ttristate \"PPP over L2TP\"\n 175:\t\tdepends on L2TP\n 176:\t\tselect PPPOX\n 177:\t\thelp\n 178:\t\t  Support for PPP-over-L2TP socket family. L2TP is a protocol\n 179:\t\t  used by ISPs and enterprises to tunnel PPP traffic over UDP\n 180:\t\t  tunnels. L2TP is replacing PPTP for VPN uses.\n 181:\tif TTY\n 182:\t\n 183:\tconfig PPP_ASYNC\n 184:\t\ttristate \"PPP support for async serial ports\"\n 185:\t\tselect CRC_CCITT\n 186:\t\thelp\n 187:\t\t  Say Y (or M) here if you want to be able to use PPP over standard\n 188:\t\t  asynchronous serial ports, such as COM1 or COM2 on a PC.  If you use\n 189:\t\t  a modem (not a synchronous or ISDN modem) to contact your ISP, you\n"
}

							input: 6054
							output: 30
							thoughts: 15

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Investigating `NET_IPGRE_DEMUX` in Kconfig**

Okay, so I'm looking at something – let's see, it's about the demultiplexing of IP GRE packets. My first thought is to zero in on where this functionality is configured: I need to check `Kconfig` for the `NET_IPGRE_DEMUX` symbol. I'm assuming it's probably a boolean or tristate, but the exact details will come out of inspecting the config. If it's enabled, that of course would suggest we want some demultiplexing; if not, there might be other means of GRE demuxing happening. I need to understand the relationship between this config option and the general GRE implementation. I'll need to dig into the dependencies and the default settings to see the typical use cases and how this aligns with the current architecture.

{
  "Expression": "config NET_IPGRE_DEMUX",
  "PathPrefix": "net/"
}

{
  "Output": "net/ipv4/Kconfig=162=config NET_IPIP\n--\nnet/ipv4/Kconfig-179-\nnet/ipv4/Kconfig:180:config NET_IPGRE_DEMUX\nnet/ipv4/Kconfig-181-\ttristate \"IP: GRE demultiplexer\"\n"
}

							input: 6397
							output: 35
							thoughts: 23

Here's a summary of my thought process, as if I were the one thinking it:

**Digging into the GRE Demux Configuration**

Okay, time to get my hands dirty. I'm going to start by examining the `net/ipv4/Kconfig` file, specifically around the `NET_IPGRE_DEMUX` option. I need to understand how this is configured and what dependencies it might have. This is likely the best place to start to trace the GRE demultiplexing functionality, and understanding its configuration is the first logical step toward understanding its behaviour within the kernel.

{
  "File": "net/ipv4/Kconfig",
  "FirstLine": 175,
  "LineCount": 25
}

{
  "Contents": " 175:\t\n 176:\t\t  Saying Y to this option will produce two modules ( = code which can\n 177:\t\t  be inserted in and removed from the running kernel whenever you\n 178:\t\t  want). Most people won't need this and can say N.\n 179:\t\n 180:\tconfig NET_IPGRE_DEMUX\n 181:\t\ttristate \"IP: GRE demultiplexer\"\n 182:\t\thelp\n 183:\t\t  This is helper module to demultiplex GRE packets on GRE version field criteria.\n 184:\t\t  Required by ip_gre and pptp modules.\n 185:\t\n 186:\tconfig NET_IP_TUNNEL\n 187:\t\ttristate\n 188:\t\tselect DST_CACHE\n 189:\t\tselect GRO_CELLS\n 190:\t\tdefault n\n 191:\t\n 192:\tconfig NET_IPGRE\n 193:\t\ttristate \"IP: GRE tunnels over IP\"\n 194:\t\tdepends on NET_IPGRE_DEMUX\n 195:\t\tselect NET_IP_TUNNEL\n 196:\t\thelp\n 197:\t\t  Tunneling means encapsulating data of one protocol type within\n 198:\t\t  another protocol and sending it over a channel that understands the\n 199:\t\t  encapsulating protocol. This particular tunneling driver implements\n"
}

							input: 6951
							output: 33
							thoughts: 21

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Diving into the pptp.c Packet Reception**

Okay, time to get my hands dirty and really understand how PPTP packet reception is handled. I need to trace the execution flow and identify the key entry points within `pptp.c`. I'm thinking I'll start by dissecting the functions in the code and map out the packet handling logic. I'm primarily interested in seeing how the datapath works, how the receive functions are called and how the packets make their way up the networking stack. Looking at the code is the only way to get a solid grasp on any nuances in the implementation, particularly for error handling or optimization tricks. I'm expecting this will involve understanding how the GRE packets are demultiplexed and, presumably, passed up to the relevant PPP layer. Let's dig in and find those crucial entry points!

{
  "Expression": "pptp_",
  "PathPrefix": "drivers/net/ppp/pptp.c"
}

{
  "Output": "drivers/net/ppp/pptp.c=47=static DEFINE_SPINLOCK(chan_lock);\ndrivers/net/ppp/pptp.c-48-\ndrivers/net/ppp/pptp.c:49:static struct proto pptp_sk_proto __read_mostly;\ndrivers/net/ppp/pptp.c:50:static const struct ppp_channel_ops pptp_chan_ops;\ndrivers/net/ppp/pptp.c:51:static const struct proto_ops pptp_ops;\ndrivers/net/ppp/pptp.c-52-\ndrivers/net/ppp/pptp.c=53=static struct pppox_sock *lookup_chan(u16 call_id, __be32 s_addr)\n--\ndrivers/net/ppp/pptp.c-55-\tstruct pppox_sock *sock;\ndrivers/net/ppp/pptp.c:56:\tstruct pptp_opt *opt;\ndrivers/net/ppp/pptp.c-57-\n--\ndrivers/net/ppp/pptp.c=72=static int lookup_chan_dst(u16 call_id, __be32 d_addr)\n--\ndrivers/net/ppp/pptp.c-74-\tstruct pppox_sock *sock;\ndrivers/net/ppp/pptp.c:75:\tstruct pptp_opt *opt;\ndrivers/net/ppp/pptp.c-76-\tint i;\n--\ndrivers/net/ppp/pptp.c=94=static int add_chan(struct pppox_sock *sock,\ndrivers/net/ppp/pptp.c:95:\t\t    struct pptp_addr *sa)\ndrivers/net/ppp/pptp.c-96-{\n--\ndrivers/net/ppp/pptp.c=124=static void del_chan(struct pppox_sock *sock)\n--\ndrivers/net/ppp/pptp.c-131-\ndrivers/net/ppp/pptp.c:132:static struct rtable *pptp_route_output(const struct pppox_sock *po,\ndrivers/net/ppp/pptp.c-133-\t\t\t\t\tstruct flowi4 *fl4)\n--\ndrivers/net/ppp/pptp.c-148-\ndrivers/net/ppp/pptp.c:149:static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)\ndrivers/net/ppp/pptp.c-150-{\n--\ndrivers/net/ppp/pptp.c-153-\tstruct net *net = sock_net(sk);\ndrivers/net/ppp/pptp.c:154:\tstruct pptp_opt *opt = \u0026po-\u003eproto.pptp;\ndrivers/net/ppp/pptp.c:155:\tstruct pptp_gre_header *hdr;\ndrivers/net/ppp/pptp.c-156-\tunsigned int header_len = sizeof(*hdr);\n--\ndrivers/net/ppp/pptp.c-169-\ndrivers/net/ppp/pptp.c:170:\trt = pptp_route_output(po, \u0026fl4);\ndrivers/net/ppp/pptp.c-171-\tif (IS_ERR(rt))\n--\ndrivers/net/ppp/pptp.c-216-\tskb_push(skb, header_len);\ndrivers/net/ppp/pptp.c:217:\thdr = (struct pptp_gre_header *)(skb-\u003edata);\ndrivers/net/ppp/pptp.c-218-\n--\ndrivers/net/ppp/pptp.c-272-\ndrivers/net/ppp/pptp.c:273:static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)\ndrivers/net/ppp/pptp.c-274-{\ndrivers/net/ppp/pptp.c-275-\tstruct pppox_sock *po = pppox_sk(sk);\ndrivers/net/ppp/pptp.c:276:\tstruct pptp_opt *opt = \u0026po-\u003eproto.pptp;\ndrivers/net/ppp/pptp.c-277-\tint headersize, payload_len, seq;\n--\ndrivers/net/ppp/pptp.c-279-\t__u8 *payload;\ndrivers/net/ppp/pptp.c:280:\tstruct pptp_gre_header *header;\ndrivers/net/ppp/pptp.c-281-\n--\ndrivers/net/ppp/pptp.c-284-\ndrivers/net/ppp/pptp.c:285:\theader = (struct pptp_gre_header *)(skb-\u003edata);\ndrivers/net/ppp/pptp.c-286-\theadersize  = sizeof(*header);\n--\ndrivers/net/ppp/pptp.c-293-\t\t\tgoto drop;\ndrivers/net/ppp/pptp.c:294:\t\theader = (struct pptp_gre_header *)(skb-\u003edata);\ndrivers/net/ppp/pptp.c-295-\n--\ndrivers/net/ppp/pptp.c-358-\ndrivers/net/ppp/pptp.c:359:static int pptp_rcv(struct sk_buff *skb)\ndrivers/net/ppp/pptp.c-360-{\ndrivers/net/ppp/pptp.c-361-\tstruct pppox_sock *po;\ndrivers/net/ppp/pptp.c:362:\tstruct pptp_gre_header *header;\ndrivers/net/ppp/pptp.c-363-\tstruct iphdr *iph;\n--\ndrivers/net/ppp/pptp.c-372-\ndrivers/net/ppp/pptp.c:373:\theader = (struct pptp_gre_header *)skb-\u003edata;\ndrivers/net/ppp/pptp.c-374-\n--\ndrivers/net/ppp/pptp.c-393-\ndrivers/net/ppp/pptp.c:394:static int pptp_bind(struct socket *sock, struct sockaddr_unsized *uservaddr,\ndrivers/net/ppp/pptp.c-395-\t\t     int sockaddr_len)\n--\ndrivers/net/ppp/pptp.c-426-\ndrivers/net/ppp/pptp.c:427:static int pptp_connect(struct socket *sock, struct sockaddr_unsized *uservaddr,\ndrivers/net/ppp/pptp.c-428-\t\t\tint sockaddr_len, int flags)\n--\ndrivers/net/ppp/pptp.c-432-\tstruct pppox_sock *po = pppox_sk(sk);\ndrivers/net/ppp/pptp.c:433:\tstruct pptp_opt *opt = \u0026po-\u003eproto.pptp;\ndrivers/net/ppp/pptp.c-434-\tstruct rtable *rt;\n--\ndrivers/net/ppp/pptp.c-465-\tpo-\u003echan.private = sk;\ndrivers/net/ppp/pptp.c:466:\tpo-\u003echan.ops = \u0026pptp_chan_ops;\ndrivers/net/ppp/pptp.c-467-\ndrivers/net/ppp/pptp.c:468:\trt = pptp_route_output(po, \u0026fl4);\ndrivers/net/ppp/pptp.c-469-\tif (IS_ERR(rt)) {\n--\ndrivers/net/ppp/pptp.c-479-\ndrivers/net/ppp/pptp.c:480:\tpo-\u003echan.hdrlen = 2 + sizeof(struct pptp_gre_header);\ndrivers/net/ppp/pptp.c-481-\tpo-\u003echan.direct_xmit = true;\n--\ndrivers/net/ppp/pptp.c-495-\ndrivers/net/ppp/pptp.c:496:static int pptp_getname(struct socket *sock, struct sockaddr *uaddr,\ndrivers/net/ppp/pptp.c-497-\tint peer)\n--\ndrivers/net/ppp/pptp.c-512-\ndrivers/net/ppp/pptp.c:513:static int pptp_release(struct socket *sock)\ndrivers/net/ppp/pptp.c-514-{\n--\ndrivers/net/ppp/pptp.c-544-\ndrivers/net/ppp/pptp.c:545:static void pptp_sock_destruct(struct sock *sk)\ndrivers/net/ppp/pptp.c-546-{\n--\ndrivers/net/ppp/pptp.c-553-\ndrivers/net/ppp/pptp.c:554:static int pptp_create(struct net *net, struct socket *sock, int kern)\ndrivers/net/ppp/pptp.c-555-{\n--\ndrivers/net/ppp/pptp.c-558-\tstruct pppox_sock *po;\ndrivers/net/ppp/pptp.c:559:\tstruct pptp_opt *opt;\ndrivers/net/ppp/pptp.c-560-\ndrivers/net/ppp/pptp.c:561:\tsk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, \u0026pptp_sk_proto, kern);\ndrivers/net/ppp/pptp.c-562-\tif (!sk)\n--\ndrivers/net/ppp/pptp.c-567-\tsock-\u003estate = SS_UNCONNECTED;\ndrivers/net/ppp/pptp.c:568:\tsock-\u003eops   = \u0026pptp_ops;\ndrivers/net/ppp/pptp.c-569-\ndrivers/net/ppp/pptp.c:570:\tsk-\u003esk_backlog_rcv = pptp_rcv_core;\ndrivers/net/ppp/pptp.c-571-\tsk-\u003esk_state       = PPPOX_NONE;\n--\ndrivers/net/ppp/pptp.c-574-\tsk-\u003esk_protocol    = PX_PROTO_PPTP;\ndrivers/net/ppp/pptp.c:575:\tsk-\u003esk_destruct    = pptp_sock_destruct;\ndrivers/net/ppp/pptp.c-576-\n--\ndrivers/net/ppp/pptp.c-587-\ndrivers/net/ppp/pptp.c:588:static int pptp_ppp_ioctl(struct ppp_channel *chan, unsigned int cmd,\ndrivers/net/ppp/pptp.c-589-\tunsigned long arg)\n--\ndrivers/net/ppp/pptp.c-592-\tstruct pppox_sock *po = pppox_sk(sk);\ndrivers/net/ppp/pptp.c:593:\tstruct pptp_opt *opt = \u0026po-\u003eproto.pptp;\ndrivers/net/ppp/pptp.c-594-\tvoid __user *argp = (void __user *)arg;\n--\ndrivers/net/ppp/pptp.c-618-\ndrivers/net/ppp/pptp.c:619:static const struct ppp_channel_ops pptp_chan_ops = {\ndrivers/net/ppp/pptp.c:620:\t.start_xmit = pptp_xmit,\ndrivers/net/ppp/pptp.c:621:\t.ioctl      = pptp_ppp_ioctl,\ndrivers/net/ppp/pptp.c-622-};\ndrivers/net/ppp/pptp.c-623-\ndrivers/net/ppp/pptp.c:624:static struct proto pptp_sk_proto __read_mostly = {\ndrivers/net/ppp/pptp.c-625-\t.name     = \"PPTP\",\n--\ndrivers/net/ppp/pptp.c-629-\ndrivers/net/ppp/pptp.c:630:static const struct proto_ops pptp_ops = {\ndrivers/net/ppp/pptp.c-631-\t.family     = AF_PPPOX,\ndrivers/net/ppp/pptp.c-632-\t.owner      = THIS_MODULE,\ndrivers/net/ppp/pptp.c:633:\t.release    = pptp_release,\ndrivers/net/ppp/pptp.c:634:\t.bind       = pptp_bind,\ndrivers/net/ppp/pptp.c:635:\t.connect    = pptp_connect,\ndrivers/net/ppp/pptp.c-636-\t.socketpair = sock_no_socketpair,\ndrivers/net/ppp/pptp.c-637-\t.accept     = sock_no_accept,\ndrivers/net/ppp/pptp.c:638:\t.getname    = pptp_getname,\ndrivers/net/ppp/pptp.c-639-\t.listen     = sock_no_listen,\n--\ndrivers/net/ppp/pptp.c-649-\ndrivers/net/ppp/pptp.c:650:static const struct pppox_proto pppox_pptp_proto = {\ndrivers/net/ppp/pptp.c:651:\t.create = pptp_create,\ndrivers/net/ppp/pptp.c-652-\t.owner  = THIS_MODULE,\n--\ndrivers/net/ppp/pptp.c-654-\ndrivers/net/ppp/pptp.c:655:static const struct gre_protocol gre_pptp_protocol = {\ndrivers/net/ppp/pptp.c:656:\t.handler = pptp_rcv,\ndrivers/net/ppp/pptp.c-657-};\ndrivers/net/ppp/pptp.c-658-\ndrivers/net/ppp/pptp.c:659:static int __init pptp_init_module(void)\ndrivers/net/ppp/pptp.c-660-{\n--\ndrivers/net/ppp/pptp.c-667-\ndrivers/net/ppp/pptp.c:668:\terr = gre_add_protocol(\u0026gre_pptp_protocol, GREPROTO_PPTP);\ndrivers/net/ppp/pptp.c-669-\tif (err) {\n--\ndrivers/net/ppp/pptp.c-673-\ndrivers/net/ppp/pptp.c:674:\terr = proto_register(\u0026pptp_sk_proto, 0);\ndrivers/net/ppp/pptp.c-675-\tif (err) {\n--\ndrivers/net/ppp/pptp.c-679-\ndrivers/net/ppp/pptp.c:680:\terr = register_pppox_proto(PX_PROTO_PPTP, \u0026pppox_pptp_proto);\ndrivers/net/ppp/pptp.c-681-\tif (err) {\n--\ndrivers/net/ppp/pptp.c-688-out_unregister_sk_proto:\ndrivers/net/ppp/pptp.c:689:\tproto_unregister(\u0026pptp_sk_proto);\ndrivers/net/ppp/pptp.c-690-out_gre_del_protocol:\ndrivers/net/ppp/pptp.c:691:\tgre_del_protocol(\u0026gre_pptp_protocol, GREPROTO_PPTP);\ndrivers/net/ppp/pptp.c-692-out_mem_free:\n--\ndrivers/net/ppp/pptp.c-697-\ndrivers/net/ppp/pptp.c:698:static void __exit pptp_exit_module(void)\ndrivers/net/ppp/pptp.c-699-{\ndrivers/net/ppp/pptp.c-700-\tunregister_pppox_proto(PX_PROTO_PPTP);\ndrivers/net/ppp/pptp.c:701:\tproto_unregister(\u0026pptp_sk_proto);\ndrivers/net/ppp/pptp.c:702:\tgre_del_protocol(\u0026gre_pptp_protocol, GREPROTO_PPTP);\ndrivers/net/ppp/pptp.c-703-\tvfree(callid_sock);\n--\ndrivers/net/ppp/pptp.c-705-\ndrivers/net/ppp/pptp.c:706:module_init(pptp_init_module);\ndrivers/net/ppp/pptp.c:707:module_exit(pptp_exit_module);\ndrivers/net/ppp/pptp.c-708-\n"
}

							input: 11340
							output: 38
							thoughts: 114

**Analyzing the PPTP GRE Packet Reception**

Okay, let's break this down. My focus right now is on how PPTP traffic is handled at the network level, specifically the reception of GRE packets. From what I understand, the function `pptp_rcv` is the designated handler for GRE packets designated with `GREPROTO_PPTP`. Essentially, it's the gatekeeper for PPTP traffic coming in over GRE.

My initial thought is that `pptp_rcv` needs to process incoming GRE packets and direct them appropriately, which it accomplishes by finding the relevant socket and passing the `skb` (socket buffer) to `sk_receive_skb`. This function then likely invokes the socket's backlog handler. This part is particularly important to investigate as it's the core of how packets are routed. `sk->sk_backlog_rcv = pptp_rcv_core` tells me that `pptp_rcv_core` is the backlog handler in this context. Now I should check exactly what the implementation of `pptp_rcv` does. I will check pptp.c lines 358-392 and dissect its implementation.

{
  "File": "drivers/net/ppp/pptp.c",
  "FirstLine": 358,
  "LineCount": 40
}

{
  "Contents": " 358:\t\n 359:\tstatic int pptp_rcv(struct sk_buff *skb)\n 360:\t{\n 361:\t\tstruct pppox_sock *po;\n 362:\t\tstruct pptp_gre_header *header;\n 363:\t\tstruct iphdr *iph;\n 364:\t\n 365:\t\tif (skb-\u003epkt_type != PACKET_HOST)\n 366:\t\t\tgoto drop;\n 367:\t\n 368:\t\tif (!pskb_may_pull(skb, 12))\n 369:\t\t\tgoto drop;\n 370:\t\n 371:\t\tiph = ip_hdr(skb);\n 372:\t\n 373:\t\theader = (struct pptp_gre_header *)skb-\u003edata;\n 374:\t\n 375:\t\tif (header-\u003egre_hd.protocol != GRE_PROTO_PPP || /* PPTP-GRE protocol for PPTP */\n 376:\t\t\tGRE_IS_CSUM(header-\u003egre_hd.flags) ||    /* flag CSUM should be clear */\n 377:\t\t\tGRE_IS_ROUTING(header-\u003egre_hd.flags) || /* flag ROUTING should be clear */\n 378:\t\t\t!GRE_IS_KEY(header-\u003egre_hd.flags) ||    /* flag KEY should be set */\n 379:\t\t\t(header-\u003egre_hd.flags \u0026 GRE_FLAGS))     /* flag Recursion Ctrl should be clear */\n 380:\t\t\t/* if invalid, discard this packet */\n 381:\t\t\tgoto drop;\n 382:\t\n 383:\t\tpo = lookup_chan(ntohs(header-\u003ecall_id), iph-\u003esaddr);\n 384:\t\tif (po) {\n 385:\t\t\tskb_dst_drop(skb);\n 386:\t\t\tnf_reset_ct(skb);\n 387:\t\t\treturn sk_receive_skb(\u0026po-\u003esk, skb, 0);\n 388:\t\t}\n 389:\tdrop:\n 390:\t\tkfree_skb(skb);\n 391:\t\treturn NET_RX_DROP;\n 392:\t}\n 393:\t\n 394:\tstatic int pptp_bind(struct socket *sock, struct sockaddr_unsized *uservaddr,\n 395:\t\t\t     int sockaddr_len)\n 396:\t{\n 397:\t\tstruct sock *sk = sock-\u003esk;\n"
}

							input: 12395
							output: 31
							thoughts: 605

**Fuzzing the PPTP GRE Handler**

Okay, so I've been looking at this patch for `pptp_rcv_core`, and it's got my attention. It's a fix related to packet length and `pskb_may_pull` checks when the kernel is processing received PPTP GRE packets. Specifically, it seems like the check now ensures that the payload availability is greater or equal than required, meaning `payload_avail >= PPP_HDRLEN + 1` and `payload_avail >= 2` are met before the code accesses the payload/data. This sounds like a functional change to packet parsing logic and bounds checking, which is a prime target for fuzzing.

Given that PPTP sockets are standard network sockets and are reachable in a virtualized environment like QEMU via standard socket system calls (think `socket(AF_PPPOX, ..., PX_PROTO_PPTP)`), receiving GRE packets (e.g., over loopback or a netns), this seems like a solid opportunity. The fact that the vulnerability is in the core network implementation, specifically within PPP and PPTP, further strengthens the case.

Now, let's nail down what functions to focus on. Obviously, `pptp_rcv_core` is a key candidate. I should also consider `pptp_rcv`, since it seems like `pptp_rcv_core` is a static function that's being used by `pptp_rcv`. Other interesting functions to include in the fuzzing focus could be `pptp_connect`, `pptp_bind`, `pptp_create`, and `pptp_xmit`. I'll have to investigate if they're static, inlined, or if I should just include them all for now. I know that `pptp_rcv_core` is static, but the address is taken by the `sk->sk_backlog_rcv = pptp_rcv_core;` assignment. Similarly, `pptp_rcv` is static, with its address being used by `gre_pptp_protocol.handler = pptp_rcv`. I should probably check the symbols defined in `pptp.c` too.

Next, I need to check the relevant Kconfig options. It looks like `PPTP` depends on `NET_IPGRE_DEMUX` and selects `PPPOX`. `NET_IPGRE_DEMUX` itself is in the `net/ipv4/Kconfig` and is also tristate. I also need to make sure the base `PPP` subsystem itself (`CONFIG_PPP`) is enabled. I should probably double-check the `drivers/net/ppp/Kconfig` file to see what menus and dependencies there are as well. This should give me a complete picture of the build requirements for successful fuzzing.

{
  "Expression": "menuconfig PPP|if PPP",
  "PathPrefix": "drivers/net/ppp"
}

{
  "Output": "drivers/net/ppp/Kconfig=6=config PPP\n--\ndrivers/net/ppp/Kconfig-34-\ndrivers/net/ppp/Kconfig:35:if PPP\ndrivers/net/ppp/Kconfig-36-\n--\ndrivers/net/ppp/Kconfig=153=config PPPOE_HASH_BITS\ndrivers/net/ppp/Kconfig-154-\tint\ndrivers/net/ppp/Kconfig:155:\tdefault 1 if PPPOE_HASH_BITS_1\ndrivers/net/ppp/Kconfig:156:\tdefault 2 if PPPOE_HASH_BITS_2\ndrivers/net/ppp/Kconfig:157:\tdefault 4 if PPPOE_HASH_BITS_4\ndrivers/net/ppp/Kconfig:158:\tdefault 8 if PPPOE_HASH_BITS_8\ndrivers/net/ppp/Kconfig-159-\tdefault 4\n"
}

							input: 13868
							output: 24
							thoughts: 25

Here's my thought process, as requested:

**Navigating the Kernel's Network Configuration**

Okay, so I need to figure out how the PPP (Point-to-Point Protocol) drivers are incorporated into this kernel build. Given my experience, the Kconfig files are the most logical place to start. I'll take a look at `drivers/net/Kconfig`. This should reveal the dependency or inclusion logic for the PPP-related options. This file likely controls the visibility and configurability of the PPP drivers during the kernel configuration process. I'm expecting to find a conditional statement or a menu entry that points me to where the PPP configuration elements are defined, if not defined directly within this `Kconfig` file itself.

{
  "Expression": "ppp",
  "PathPrefix": "drivers/net"
}

{
  "Output": "\nFull output is too long, showing 500 out of 5302 lines.\nUse more precise expression if possible.\n\ndrivers/net/Kconfig=526=source \"drivers/net/plip/Kconfig\"\ndrivers/net/Kconfig-527-\ndrivers/net/Kconfig:528:source \"drivers/net/ppp/Kconfig\"\ndrivers/net/Kconfig-529-\n--\ndrivers/net/Makefile=57=obj-$(CONFIG_PLIP) += plip/\ndrivers/net/Makefile:58:obj-$(CONFIG_PPP) += ppp/\ndrivers/net/Makefile:59:obj-$(CONFIG_PPP_ASYNC) += ppp/\ndrivers/net/Makefile:60:obj-$(CONFIG_PPP_BSDCOMP) += ppp/\ndrivers/net/Makefile:61:obj-$(CONFIG_PPP_DEFLATE) += ppp/\ndrivers/net/Makefile:62:obj-$(CONFIG_PPP_MPPE) += ppp/\ndrivers/net/Makefile:63:obj-$(CONFIG_PPP_SYNC_TTY) += ppp/\ndrivers/net/Makefile:64:obj-$(CONFIG_PPPOE) += ppp/\ndrivers/net/Makefile:65:obj-$(CONFIG_PPPOL2TP) += ppp/\ndrivers/net/Makefile:66:obj-$(CONFIG_PPTP) += ppp/\ndrivers/net/Makefile-67-obj-$(CONFIG_SLIP) += slip/\n--\ndrivers/net/dsa/yt921x.c=3857=yt921x_dsa_port_set_default_prio(struct dsa_switch *ds, int port, u8 prio)\n--\ndrivers/net/dsa/yt921x.c-3875-\ndrivers/net/dsa/yt921x.c:3876:static int __maybe_unused appprios_cmp(const void *a, const void *b)\ndrivers/net/dsa/yt921x.c-3877-{\n--\ndrivers/net/dsa/yt921x.c=3882=yt921x_dsa_port_get_apptrust(struct dsa_switch *ds, int port, u8 *sel,\n--\ndrivers/net/dsa/yt921x.c-3885-\tstruct yt921x_priv *priv = to_yt921x_priv(ds);\ndrivers/net/dsa/yt921x.c:3886:\tu8 appprios[2][2] = {};\ndrivers/net/dsa/yt921x.c-3887-\tint nsel;\n--\ndrivers/net/dsa/yt921x.c-3897-\ndrivers/net/dsa/yt921x.c:3898:\tappprios[0][0] = IEEE_8021QAZ_APP_SEL_DSCP;\ndrivers/net/dsa/yt921x.c:3899:\tappprios[0][1] = (val \u003e\u003e (3 * YT921X_APP_SEL_DSCP)) \u0026 7;\ndrivers/net/dsa/yt921x.c:3900:\tappprios[1][0] = DCB_APP_SEL_PCP;\ndrivers/net/dsa/yt921x.c:3901:\tappprios[1][1] = (val \u003e\u003e (3 * YT921X_APP_SEL_CVLAN_PCP)) \u0026 7;\ndrivers/net/dsa/yt921x.c:3902:\tsort(appprios, ARRAY_SIZE(appprios), sizeof(appprios[0]), appprios_cmp,\ndrivers/net/dsa/yt921x.c-3903-\t     NULL);\n--\ndrivers/net/dsa/yt921x.c-3905-\tnsel = 0;\ndrivers/net/dsa/yt921x.c:3906:\tfor (int i = 0; i \u003c ARRAY_SIZE(appprios) \u0026\u0026 appprios[i][1]; i++) {\ndrivers/net/dsa/yt921x.c:3907:\t\tsel[nsel] = appprios[i][0];\ndrivers/net/dsa/yt921x.c-3908-\t\tnsel++;\n--\ndrivers/net/ethernet/airoha/airoha_eth.c-14-#include \u003cnet/pkt_cls.h\u003e\ndrivers/net/ethernet/airoha/airoha_eth.c:15:#include \u003cuapi/linux/ppp_defs.h\u003e\ndrivers/net/ethernet/airoha/airoha_eth.c-16-\n--\ndrivers/net/ethernet/airoha/airoha_eth.h=313=struct airoha_foe_mac_info {\n--\ndrivers/net/ethernet/airoha/airoha_eth.h-315-\ndrivers/net/ethernet/airoha/airoha_eth.h:316:\tu16 pppoe_id;\ndrivers/net/ethernet/airoha/airoha_eth.h-317-\tu16 src_mac_lo;\n--\ndrivers/net/ethernet/airoha/airoha_eth.h=473=struct airoha_flow_data {\n--\ndrivers/net/ethernet/airoha/airoha_eth.h-500-\t\tu8 num;\ndrivers/net/ethernet/airoha/airoha_eth.h:501:\t} pppoe;\ndrivers/net/ethernet/airoha/airoha_eth.h-502-};\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c=342=static int airoha_ppe_foe_entry_prepare(struct airoha_eth *eth,\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-359-\t      FIELD_PREP(AIROHA_FOE_IB1_BIND_VPM, data-\u003evlan.num) |\ndrivers/net/ethernet/airoha/airoha_ppe.c:360:\t      FIELD_PREP(AIROHA_FOE_IB1_BIND_PPPOE, data-\u003epppoe.num) |\ndrivers/net/ethernet/airoha/airoha_ppe.c-361-\t      AIROHA_FOE_IB1_BIND_TTL;\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-455-\t\tmac_info = (struct airoha_foe_mac_info *)l2;\ndrivers/net/ethernet/airoha/airoha_ppe.c:456:\t\tmac_info-\u003epppoe_id = data-\u003epppoe.sid;\ndrivers/net/ethernet/airoha/airoha_ppe.c-457-\t} else {\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-459-\t\t\t\t FIELD_PREP(AIROHA_FOE_MAC_PPPOE_ID,\ndrivers/net/ethernet/airoha/airoha_ppe.c:460:\t\t\t\t\t    data-\u003epppoe.sid);\ndrivers/net/ethernet/airoha/airoha_ppe.c-461-\t}\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-473-\t\tl2-\u003eetype |= !data-\u003evlan.num ? BIT(15) : 0;\ndrivers/net/ethernet/airoha/airoha_ppe.c:474:\t} else if (data-\u003epppoe.num) {\ndrivers/net/ethernet/airoha/airoha_ppe.c-475-\t\tl2-\u003eetype = ETH_P_PPP_SES;\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c=1088=static int airoha_ppe_flow_offload_replace(struct airoha_eth *eth,\n--\ndrivers/net/ethernet/airoha/airoha_ppe.c-1177-\t\tcase FLOW_ACTION_PPPOE_PUSH:\ndrivers/net/ethernet/airoha/airoha_ppe.c:1178:\t\t\tif (data.pppoe.num == 1 || data.vlan.num == 2)\ndrivers/net/ethernet/airoha/airoha_ppe.c-1179-\t\t\t\treturn -EOPNOTSUPP;\ndrivers/net/ethernet/airoha/airoha_ppe.c-1180-\ndrivers/net/ethernet/airoha/airoha_ppe.c:1181:\t\t\tdata.pppoe.sid = act-\u003epppoe.sid;\ndrivers/net/ethernet/airoha/airoha_ppe.c:1182:\t\t\tdata.pppoe.num++;\ndrivers/net/ethernet/airoha/airoha_ppe.c-1183-\t\t\tbreak;\n--\ndrivers/net/ethernet/broadcom/bcmsysport.c=191=static const struct bcm_sysport_stats bcm_sysport_gstrings_stats[] = {\n--\ndrivers/net/ethernet/broadcom/bcmsysport.c-229-\tSTAT_MIB_RX(\"rx_unicast\", mib.rx.uc),\ndrivers/net/ethernet/broadcom/bcmsysport.c:230:\tSTAT_MIB_RX(\"rx_ppp\", mib.rx.ppp),\ndrivers/net/ethernet/broadcom/bcmsysport.c-231-\tSTAT_MIB_RX(\"rx_crc\", mib.rx.rcrc),\n--\ndrivers/net/ethernet/broadcom/bcmsysport.h=511=struct bcm_sysport_rx_counters {\n--\ndrivers/net/ethernet/broadcom/bcmsysport.h-529-\tu32\tuc;\t\t/* RO # of unicast pkt */\ndrivers/net/ethernet/broadcom/bcmsysport.h:530:\tu32\tppp;\t\t/* RO # of PPP pkt */\ndrivers/net/ethernet/broadcom/bcmsysport.h-531-\tu32\trcrc;\t\t/* RO (0x470),# of CRC match pkt */\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c=2118=static void bnx2x_update_pfc_nig(struct link_params *params,\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2121-{\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c:2122:\tu32 xcm_mask = 0, ppp_enable = 0, pause_enable = 0, llfc_out_en = 0;\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2123-\tu32 llfc_enable = 0, xcm_out_en = 0, hwpfc_enable = 0;\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2145-\t\tif (CHIP_IS_E3(bp))\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c:2146:\t\t\tppp_enable = 0;\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2147-\t\telse\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c:2148:\t\t\tppp_enable = 1;\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2149-\t\txcm_mask \u0026= ~(port ? NIG_LLH1_XCM_MASK_REG_LLH1_XCM_MASK_BCN :\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2176-\tREG_WR(bp, port ? NIG_REG_PPP_ENABLE_1 :\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c:2177:\t       NIG_REG_PPP_ENABLE_0, ppp_enable);\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c-2178-\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h=871=extern const u32 dmae_reg_go_c[];\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2062-#define NIG_REG_LED_MODE_P0\t\t\t\t\t 0x102f0\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h:2063:/* [RW 3] for port0 enable for llfc ppp and pause. b0 - brb1 enable; b1-\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2064-   tsdm enable; b2- usdm enable */\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2067-/* [RW 1] SAFC enable for port0. This register may get 1 only when\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h:2068:   ~ppp_enable.ppp_enable = 0 and pause_enable.pause_enable =0 for the same\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2069-   port */\n--\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2640-/* [RW 1] Pause enable for port0. This register may get 1 only when\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h:2641:   ~safc_enable.safc_enable = 0 and ppp_enable.ppp_enable =0 for the same\ndrivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h-2642-   port */\n--\ndrivers/net/ethernet/broadcom/genet/bcmgenet.c=1073=static const struct bcmgenet_stats bcmgenet_gstrings_stats[] = {\n--\ndrivers/net/ethernet/broadcom/genet/bcmgenet.c-1116-\tSTAT_GENET_MIB_RX(\"rx_unicast\", mib.rx.uc),\ndrivers/net/ethernet/broadcom/genet/bcmgenet.c:1117:\tSTAT_GENET_MIB_RX(\"rx_ppp\", mib.rx.ppp),\ndrivers/net/ethernet/broadcom/genet/bcmgenet.c-1118-\tSTAT_GENET_MIB_RX(\"rx_crc\", mib.rx.rcrc),\n--\ndrivers/net/ethernet/broadcom/genet/bcmgenet.h=95=struct bcmgenet_rx_counters {\n--\ndrivers/net/ethernet/broadcom/genet/bcmgenet.h-113-\tu32\tuc;\t\t/* RO # of unicast pkt */\ndrivers/net/ethernet/broadcom/genet/bcmgenet.h:114:\tu32\tppp;\t\t/* RO # of PPP pkt */\ndrivers/net/ethernet/broadcom/genet/bcmgenet.h-115-\tu32\trcrc;\t\t/* RO (0x470),# of CRC match pkt */\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h=205=struct port_stats {\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h-222-\tu64 tx_pause;             /* # of transmitted pause frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:223:\tu64 tx_ppp0;              /* # of transmitted PPP prio 0 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:224:\tu64 tx_ppp1;              /* # of transmitted PPP prio 1 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:225:\tu64 tx_ppp2;              /* # of transmitted PPP prio 2 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:226:\tu64 tx_ppp3;              /* # of transmitted PPP prio 3 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:227:\tu64 tx_ppp4;              /* # of transmitted PPP prio 4 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:228:\tu64 tx_ppp5;              /* # of transmitted PPP prio 5 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:229:\tu64 tx_ppp6;              /* # of transmitted PPP prio 6 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:230:\tu64 tx_ppp7;              /* # of transmitted PPP prio 7 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h-231-\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h-252-\tu64 rx_pause;             /* # of received pause frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:253:\tu64 rx_ppp0;              /* # of received PPP prio 0 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:254:\tu64 rx_ppp1;              /* # of received PPP prio 1 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:255:\tu64 rx_ppp2;              /* # of received PPP prio 2 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:256:\tu64 rx_ppp3;              /* # of received PPP prio 3 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:257:\tu64 rx_ppp4;              /* # of received PPP prio 4 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:258:\tu64 rx_ppp5;              /* # of received PPP prio 5 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:259:\tu64 rx_ppp6;              /* # of received PPP prio 6 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h:260:\tu64 rx_ppp7;              /* # of received PPP prio 7 frames */\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4.h-261-\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c=45=static const char stats_strings[][ETH_GSTRING_LEN] = {\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c-62-\t\"tx_pause_frames        \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:63:\t\"tx_ppp0_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:64:\t\"tx_ppp1_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:65:\t\"tx_ppp2_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:66:\t\"tx_ppp3_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:67:\t\"tx_ppp4_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:68:\t\"tx_ppp5_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:69:\t\"tx_ppp6_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:70:\t\"tx_ppp7_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c-71-\n--\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c-93-\t\"rx_pause_frames        \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:94:\t\"rx_ppp0_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:95:\t\"rx_ppp1_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:96:\t\"rx_ppp2_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:97:\t\"rx_ppp3_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:98:\t\"rx_ppp4_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:99:\t\"rx_ppp5_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:100:\t\"rx_ppp6_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c:101:\t\"rx_ppp7_frames         \",\ndrivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c-102-\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c=6345=void t4_get_port_stats(struct adapter *adap, int idx, struct port_stats *p)\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c-6370-\tp-\u003etx_pause            = GET_STAT(TX_PORT_PAUSE);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6371:\tp-\u003etx_ppp0             = GET_STAT(TX_PORT_PPP0);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6372:\tp-\u003etx_ppp1             = GET_STAT(TX_PORT_PPP1);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6373:\tp-\u003etx_ppp2             = GET_STAT(TX_PORT_PPP2);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6374:\tp-\u003etx_ppp3             = GET_STAT(TX_PORT_PPP3);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6375:\tp-\u003etx_ppp4             = GET_STAT(TX_PORT_PPP4);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6376:\tp-\u003etx_ppp5             = GET_STAT(TX_PORT_PPP5);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6377:\tp-\u003etx_ppp6             = GET_STAT(TX_PORT_PPP6);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6378:\tp-\u003etx_ppp7             = GET_STAT(TX_PORT_PPP7);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c-6379-\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c-6404-\tp-\u003erx_pause            = GET_STAT(RX_PORT_PAUSE);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6405:\tp-\u003erx_ppp0             = GET_STAT(RX_PORT_PPP0);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6406:\tp-\u003erx_ppp1             = GET_STAT(RX_PORT_PPP1);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6407:\tp-\u003erx_ppp2             = GET_STAT(RX_PORT_PPP2);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6408:\tp-\u003erx_ppp3             = GET_STAT(RX_PORT_PPP3);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6409:\tp-\u003erx_ppp4             = GET_STAT(RX_PORT_PPP4);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6410:\tp-\u003erx_ppp5             = GET_STAT(RX_PORT_PPP5);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6411:\tp-\u003erx_ppp6             = GET_STAT(RX_PORT_PPP6);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6412:\tp-\u003erx_ppp7             = GET_STAT(RX_PORT_PPP7);\ndrivers/net/ethernet/chelsio/cxgb4/t4_hw.c-6413-\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h=3210=struct fw_port_stats_cmd {\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h-3241-\t\t\t__be64 tx_pause;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3242:\t\t\t__be64 tx_ppp0;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3243:\t\t\t__be64 tx_ppp1;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3244:\t\t\t__be64 tx_ppp2;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3245:\t\t\t__be64 tx_ppp3;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3246:\t\t\t__be64 tx_ppp4;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3247:\t\t\t__be64 tx_ppp5;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3248:\t\t\t__be64 tx_ppp6;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3249:\t\t\t__be64 tx_ppp7;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h-3250-\t\t\t__be64 rx_bytes;\n--\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h-3267-\t\t\t__be64 rx_pause;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3268:\t\t\t__be64 rx_ppp0;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3269:\t\t\t__be64 rx_ppp1;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3270:\t\t\t__be64 rx_ppp2;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3271:\t\t\t__be64 rx_ppp3;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3272:\t\t\t__be64 rx_ppp4;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3273:\t\t\t__be64 rx_ppp5;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3274:\t\t\t__be64 rx_ppp6;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h:3275:\t\t\t__be64 rx_ppp7;\ndrivers/net/ethernet/chelsio/cxgb4/t4fw_api.h-3276-\t\t\t__be64 rx_less_64b;\n--\ndrivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h=213=struct dpaa2_fapr {\n--\ndrivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h-236-\tu8 mpls_offset_1;\ndrivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h:237:\tu8 pppoe_offset;\ndrivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h-238-\t/* 64-bit word 5 */\n--\ndrivers/net/ethernet/freescale/fman/fman.h=114=struct fman_prs_result {\n--\ndrivers/net/ethernet/freescale/fman/fman.h-134-\tu8 etype_off;\t\t/* ETYPE offset */\ndrivers/net/ethernet/freescale/fman/fman.h:135:\tu8 pppoe_off;\t\t/* PPP offset */\ndrivers/net/ethernet/freescale/fman/fman.h-136-\tu8 mpls_off[2];\t\t/* MPLS offset */\n--\ndrivers/net/ethernet/freescale/fs_enet/fs_enet.h=74=struct fs_ops {\n--\ndrivers/net/ethernet/freescale/fs_enet/fs_enet.h-97- */\ndrivers/net/ethernet/freescale/fs_enet/fs_enet.h:98:#define MAX_MTU 1508\t\t/* Allow fullsized pppoe packets over VLAN */\ndrivers/net/ethernet/freescale/fs_enet/fs_enet.h-99-#define MIN_MTU 46\t\t/* this is data size */\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c=47=static struct hns3_dbg_cmd_info hns3_dbg_cmd[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c-222-\t{\ndrivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c:223:\t\t.name = \"ppp\",\ndrivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c-224-\t\t.cmd = HNAE3_DBG_CMD_REG_PPP,\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c=390=static const struct hclge_dbg_dfx_message hclge_dbg_rtc_reg[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-419-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:420:static const struct hclge_dbg_dfx_message hclge_dbg_ppp_reg[] = {\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-421-\t{false, \"Reserved\"},\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c=664=static const struct hclge_dbg_reg_type_info hclge_dbg_reg_info[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-710-\t{ .cmd = HNAE3_DBG_CMD_REG_PPP,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:711:\t  .dfx_msg = \u0026hclge_dbg_ppp_reg[0],\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:712:\t  .reg_msg = { .msg_num = ARRAY_SIZE(hclge_dbg_ppp_reg),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-713-\t\t       .offset = HCLGE_DBG_DFX_PPP_OFFSET,\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c=1249=static int hclge_dbg_dump_rtc_reg_cmd(struct seq_file *s, void *data)\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-1253-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:1254:static int hclge_dbg_dump_ppp_reg_cmd(struct seq_file *s, void *data)\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-1255-{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c=2938=static const struct hclge_dbg_func hclge_dbg_cmd_func[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-3044-\t\t.cmd = HNAE3_DBG_CMD_REG_PPP,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:3045:\t\t.dbg_read_func = hclge_dbg_dump_ppp_reg_cmd,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c-3046-\t},\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=208=static const struct hclge_hw_error hclge_ncsi_err_int[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-217-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:218:static const struct hclge_hw_error hclge_ppp_mpf_abnormal_int_st1[] = {\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-219-\t{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-347-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:348:static const struct hclge_hw_error hclge_ppp_pf_abnormal_int[] = {\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-349-\t{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-361-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:362:static const struct hclge_hw_error hclge_ppp_mpf_abnormal_int_st3[] = {\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-363-\t{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=846=static const struct hclge_hw_error hclge_ssu_com_err_int[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-852-\t\t.int_msk = BIT(1),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:853:\t\t.msg = \"ppp_mb_num_err\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-854-\t\t.reset_level = HNAE3_NONE_RESET\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-856-\t\t.int_msk = BIT(2),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:857:\t\t.msg = \"ppp_mbid_err\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-858-\t\t.reset_level = HNAE3_GLOBAL_RESET\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-860-\t\t.int_msk = BIT(3),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:861:\t\t.msg = \"ppp_rlt_mac_err\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-862-\t\t.reset_level = HNAE3_GLOBAL_RESET\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-864-\t\t.int_msk = BIT(4),\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:865:\t\t.msg = \"ppp_rlt_host_err\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-866-\t\t.reset_level = HNAE3_GLOBAL_RESET\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=1879=static int hclge_config_igu_egu_hw_err_int(struct hclge_dev *hdev, bool en)\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1917-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:1918:static int hclge_config_ppp_error_interrupt(struct hclge_dev *hdev, u32 cmd,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1919-\t\t\t\t\t    bool en)\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1966-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:1967:static int hclge_config_ppp_hw_err_int(struct hclge_dev *hdev, bool en)\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1968-{\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1970-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:1971:\tret = hclge_config_ppp_error_interrupt(hdev, HCLGE_PPP_CMD0_INT_CMD,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1972-\t\t\t\t\t       en);\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1975-\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:1976:\tret = hclge_config_ppp_error_interrupt(hdev, HCLGE_PPP_CMD1_INT_CMD,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-1977-\t\t\t\t\t       en);\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=2250=static int hclge_handle_mpf_ras_error(struct hclge_dev *hdev,\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2330-\t\thclge_log_error(dev, \"PPP_MPF_ABNORMAL_INT_ST1\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:2331:\t\t\t\t\u0026hclge_ppp_mpf_abnormal_int_st1[0], status,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2332-\t\t\t\t\u0026ae_dev-\u003ehw_err_reset_req);\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2336-\t\thclge_log_error(dev, \"PPP_MPF_ABNORMAL_INT_ST3\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:2337:\t\t\t\t\u0026hclge_ppp_mpf_abnormal_int_st3[0], status,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2338-\t\t\t\t\u0026ae_dev-\u003ehw_err_reset_req);\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=2716=static const struct hclge_hw_blk hw_blk[] = {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2723-\t\t.name = \"PPP\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:2724:\t\t.config_err_int = hclge_config_ppp_hw_err_int,\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-2725-\t}, {\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c=2975=static int hclge_handle_pf_msix_error(struct hclge_dev *hdev,\n--\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-3005-\t\thclge_log_error(dev, \"PPP_PF_ABNORMAL_INT_ST0\",\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:3006:\t\t\t\t\u0026hclge_ppp_pf_abnormal_int[0],\ndrivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c-3007-\t\t\t\tstatus, reset_requests);\n--\ndrivers/net/ethernet/intel/ice/ice.h-56-#include \u003cnet/gtp.h\u003e\ndrivers/net/ethernet/intel/ice/ice.h:57:#include \u003clinux/ppp_defs.h\u003e\ndrivers/net/ethernet/intel/ice/ice.h-58-#include \"ice_devids.h\"\n--\ndrivers/net/ethernet/intel/ice/ice_fdir.h=132=struct ice_fdir_udp_gtp {\n--\ndrivers/net/ethernet/intel/ice/ice_fdir.h-142-\t\tspare:4;\ndrivers/net/ethernet/intel/ice/ice_fdir.h:143:\tu8\tppp:1,\ndrivers/net/ethernet/intel/ice/ice_fdir.h-144-\t\trqi:1,\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c=587=static const u32 ice_ptypes_gtpu[] = {\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c-598-/* Packet types for PPPoE */\ndrivers/net/ethernet/intel/ice/ice_flow.c:599:static const u32 ice_ptypes_pppoe[] = {\ndrivers/net/ethernet/intel/ice/ice_flow.c-600-\t0x00000000, 0x00000000, 0x00000000, 0x00000000,\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c=807=static int ice_flow_proc_seg_hdrs(struct ice_flow_prof_params *params)\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c-881-\t\t} else if (hdrs \u0026 ICE_FLOW_SEG_HDR_PPPOE) {\ndrivers/net/ethernet/intel/ice/ice_flow.c:882:\t\t\tsrc = (const unsigned long *)ice_ptypes_pppoe;\ndrivers/net/ethernet/intel/ice/ice_flow.c-883-\t\t\tbitmap_and(params-\u003eptypes, params-\u003eptypes, src,\n--\ndrivers/net/ethernet/intel/ice/ice_flow.c-885-\t\t} else {\ndrivers/net/ethernet/intel/ice/ice_flow.c:886:\t\t\tsrc = (const unsigned long *)ice_ptypes_pppoe;\ndrivers/net/ethernet/intel/ice/ice_flow.c-887-\t\t\tbitmap_andnot(params-\u003eptypes, params-\u003eptypes, src,\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h=233=struct ice_pfcp_hdr {\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-241-\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h:242:struct ice_pppoe_hdr {\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-243-\tu8 rsrvd_ver_type;\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-246-\t__be16 length;\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h:247:\t__be16 ppp_prot_id; /* control and data only */\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-248-};\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h=447=union ice_prot_hdr {\n--\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-458-\tstruct ice_pfcp_hdr pfcp_hdr;\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h:459:\tstruct ice_pppoe_hdr pppoe_hdr;\ndrivers/net/ethernet/intel/ice/ice_protocol_type.h-460-\tstruct ice_l2tpv3_sess_hdr l2tpv3_sess_hdr;\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c=1157=ICE_DECLARE_PKT_TEMPLATE(pfcp_session_ipv6) = {\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1185-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1186:ICE_DECLARE_PKT_OFFSETS(pppoe_ipv4_tcp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1187-\t{ ICE_MAC_OFOS,\t\t0 },\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1194-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1195:ICE_DECLARE_PKT_TEMPLATE(pppoe_ipv4_tcp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1196-\t0x00, 0x00, 0x00, 0x00, /* ICE_MAC_OFOS 0 */\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1221-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1222:ICE_DECLARE_PKT_OFFSETS(pppoe_ipv4_udp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1223-\t{ ICE_MAC_OFOS,\t\t0 },\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1230-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1231:ICE_DECLARE_PKT_TEMPLATE(pppoe_ipv4_udp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1232-\t0x00, 0x00, 0x00, 0x00, /* ICE_MAC_OFOS 0 */\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1254-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1255:ICE_DECLARE_PKT_OFFSETS(pppoe_ipv6_tcp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1256-\t{ ICE_MAC_OFOS,\t\t0 },\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1263-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1264:ICE_DECLARE_PKT_TEMPLATE(pppoe_ipv6_tcp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1265-\t0x00, 0x00, 0x00, 0x00, /* ICE_MAC_OFOS 0 */\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1295-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1296:ICE_DECLARE_PKT_OFFSETS(pppoe_ipv6_udp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1297-\t{ ICE_MAC_OFOS,\t\t0 },\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1304-\ndrivers/net/ethernet/intel/ice/ice_switch.c:1305:ICE_DECLARE_PKT_TEMPLATE(pppoe_ipv6_udp) = {\ndrivers/net/ethernet/intel/ice/ice_switch.c-1306-\t0x00, 0x00, 0x00, 0x00, /* ICE_MAC_OFOS 0 */\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c=1393=static const struct ice_dummy_pkt_profile ice_dummy_pkt_profiles[] = {\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-1420-\tICE_PKT_PROFILE(pfcp_session_ipv4, ICE_PKT_PFCP),\ndrivers/net/ethernet/intel/ice/ice_switch.c:1421:\tICE_PKT_PROFILE(pppoe_ipv6_udp, ICE_PKT_PPPOE | ICE_PKT_OUTER_IPV6 |\ndrivers/net/ethernet/intel/ice/ice_switch.c-1422-\t\t\t\t\tICE_PKT_INNER_UDP),\ndrivers/net/ethernet/intel/ice/ice_switch.c:1423:\tICE_PKT_PROFILE(pppoe_ipv6_tcp, ICE_PKT_PPPOE | ICE_PKT_OUTER_IPV6),\ndrivers/net/ethernet/intel/ice/ice_switch.c:1424:\tICE_PKT_PROFILE(pppoe_ipv4_udp, ICE_PKT_PPPOE | ICE_PKT_INNER_UDP),\ndrivers/net/ethernet/intel/ice/ice_switch.c:1425:\tICE_PKT_PROFILE(pppoe_ipv4_tcp, ICE_PKT_PPPOE),\ndrivers/net/ethernet/intel/ice/ice_switch.c-1426-\tICE_PKT_PROFILE(gre_ipv6_tcp, ICE_PKT_TUN_NVGRE | ICE_PKT_INNER_IPV6 |\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c=5557=ice_find_dummy_packet(struct ice_adv_lkup_elem *lkups, u16 lkups_cnt,\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-5614-\t\t\tmatch |= ICE_PKT_PPPOE;\ndrivers/net/ethernet/intel/ice/ice_switch.c:5615:\t\t\tif (lkups[i].h_u.pppoe_hdr.ppp_prot_id ==\ndrivers/net/ethernet/intel/ice/ice_switch.c-5616-\t\t\t    htons(PPP_IPV6))\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c=5641=ice_fill_adv_dummy_packet(struct ice_adv_lkup_elem *lkups, u16 lkups_cnt,\n--\ndrivers/net/ethernet/intel/ice/ice_switch.c-5724-\t\tcase ICE_PPPOE:\ndrivers/net/ethernet/intel/ice/ice_switch.c:5725:\t\t\tlen = sizeof(struct ice_pppoe_hdr);\ndrivers/net/ethernet/intel/ice/ice_switch.c-5726-\t\t\tbreak;\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c=371=ice_tc_fill_rules(struct ice_hw *hw, u32 flags,\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-490-\t\t     ICE_TC_FLWR_FIELD_PPP_PROTO)) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:491:\t\tstruct ice_pppoe_hdr *vals, *masks;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-492-\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:493:\t\tvals = \u0026list[i].h_u.pppoe_hdr;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:494:\t\tmasks = \u0026list[i].m_u.pppoe_hdr;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-495-\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-498-\t\tif (flags \u0026 ICE_TC_FLWR_FIELD_PPPOE_SESSID) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:499:\t\t\tvals-\u003esession_id = headers-\u003epppoe_hdr.session_id;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-500-\t\t\tmasks-\u003esession_id = cpu_to_be16(0xFFFF);\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-503-\t\tif (flags \u0026 ICE_TC_FLWR_FIELD_PPP_PROTO) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:504:\t\t\tvals-\u003eppp_prot_id = headers-\u003epppoe_hdr.ppp_proto;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:505:\t\t\tmasks-\u003eppp_prot_id = cpu_to_be16(0xFFFF);\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-506-\t\t}\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c=1141=ice_add_tc_flower_adv_fltr(struct ice_vsi *vsi,\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1289-/**\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1290: * ice_tc_set_pppoe - Parse PPPoE fields from TC flower filter\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1291- * @match: Pointer to flow match structure\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1293- * @headers: Pointer to outer header fields\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1294: * @returns PPP protocol used in filter (ppp_ses or ppp_disc)\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1295- */\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c=1296=static u16\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1297:ice_tc_set_pppoe(struct flow_match_pppoe *match,\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1298-\t\t struct ice_tc_flower_fltr *fltr,\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1302-\t\tfltr-\u003eflags |= ICE_TC_FLWR_FIELD_PPPOE_SESSID;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1303:\t\theaders-\u003epppoe_hdr.session_id = match-\u003ekey-\u003esession_id;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1304-\t}\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1305-\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1306:\tif (match-\u003emask-\u003eppp_proto) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1307-\t\tfltr-\u003eflags |= ICE_TC_FLWR_FIELD_PPP_PROTO;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1308:\t\theaders-\u003epppoe_hdr.ppp_proto = match-\u003ekey-\u003eppp_proto;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1309-\t}\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c=1637=ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi,\n--\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1837-\tif (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_PPPOE)) {\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c:1838:\t\tstruct flow_match_pppoe match;\ndrivers/net/ethernet/intel/ice/ice_tc_lib.c-1839-\n\n"
}

							input: 29705
							output: 34
							thoughts: 26

Here's my take on those thoughts:

**PPTP Configuration Deep Dive**

Okay, time to circle back and double-check something crucial for this PPTP integration. I need to be absolutely certain I haven't missed any dependencies in the kernel configuration. I should re-examine `drivers/net/ppp/Kconfig` again, meticulously. It’s too easy to overlook something in these nested configurations, especially with the potential for interactions between different network subsystems. I want to build a bulletproof understanding, so a fresh look is essential before I proceed any further.

{
  "File": "drivers/net/ppp/Kconfig",
  "FirstLine": 1,
  "LineCount": 40
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\t#\n   3:\t# PPP network device configuration\n   4:\t#\n   5:\t\n   6:\tconfig PPP\n   7:\t\ttristate \"PPP (point-to-point protocol) support\"\n   8:\t\tselect SLHC\n   9:\t\thelp\n  10:\t\t  PPP (Point to Point Protocol) is a newer and better SLIP.  It serves\n  11:\t\t  the same purpose: sending Internet traffic over telephone (and other\n  12:\t\t  serial) lines.  Ask your access provider if they support it, because\n  13:\t\t  otherwise you can't use it; most Internet access providers these\n  14:\t\t  days support PPP rather than SLIP.\n  15:\t\n  16:\t\t  To use PPP, you need an additional program called pppd, available at\n  17:\t\t  \u003chttps://ppp.samba.org\u003e.  Make sure that you have the version of pppd\n  18:\t\t  recommended in \u003cfile:Documentation/Changes\u003e.\n  19:\t\t  The PPP option enlarges your kernel by about 16 KB.\n  20:\t\n  21:\t\t  There are actually two versions of PPP: the traditional PPP for\n  22:\t\t  asynchronous lines, such as regular analog phone lines, and\n  23:\t\t  synchronous PPP which can be used over digital ISDN lines for\n  24:\t\t  example.  If you want to use PPP over phone lines or other\n  25:\t\t  asynchronous serial lines, you need to say Y (or M) here and also to\n  26:\t\t  the next option, \"PPP support for async serial ports\".  For PPP over\n  27:\t\t  synchronous lines, you should say Y (or M) here and to \"Support\n  28:\t\t  synchronous PPP\", below.\n  29:\t\n  30:\t\t  If you said Y to \"Version information on all symbols\" above, then\n  31:\t\t  you cannot compile the PPP driver into the kernel; you can then only\n  32:\t\t  compile it as a module. To compile this driver as a module, choose M\n  33:\t\t  here. The module will be called ppp_generic.\n  34:\t\n  35:\tif PPP\n  36:\t\n  37:\tconfig PPP_BSDCOMP\n  38:\t\ttristate \"PPP BSD-Compress compression\"\n  39:\t\thelp\n  40:\t\t  Support for the BSD-Compress compression method for PPP, which uses\n"
}

							input: 30515
							output: 35
							thoughts: 148

**My Analysis of PPTP Configuration Options**

Okay, let's break this down. From what I'm seeing, `PPTP` is nested within an `if PPP ... endif` block. This tells me that `CONFIG_PPP` is a prerequisite for enabling the `PPTP` option, and therefore so is `CONFIG_PPTP`, and also `CONFIG_NET_IPGRE_DEMUX`, which `PPTP` relies upon. And further, it looks like `PPTP` also automatically selects `PPPOX` via `CONFIG_PPPOX`.

Now, I need to confirm whether `CONFIG_INET` or any other core network configuration elements are essential here. Let's see... looking at the `net/ipv4/Kconfig` file, `NET_IPGRE_DEMUX` – which is *required* for PPTP – depends on `INET`. Given that `INET` is fundamentally standard networking functionality, that makes perfect sense. I will now double-check `net/ipv4/Kconfig` directly for any other `NET_IPGRE_DEMUX` dependencies to complete the picture.

{
  "File": "net/ipv4/Kconfig",
  "FirstLine": 178,
  "LineCount": 15
}

{
  "Contents": " 178:\t\t  want). Most people won't need this and can say N.\n 179:\t\n 180:\tconfig NET_IPGRE_DEMUX\n 181:\t\ttristate \"IP: GRE demultiplexer\"\n 182:\t\thelp\n 183:\t\t  This is helper module to demultiplex GRE packets on GRE version field criteria.\n 184:\t\t  Required by ip_gre and pptp modules.\n 185:\t\n 186:\tconfig NET_IP_TUNNEL\n 187:\t\ttristate\n 188:\t\tselect DST_CACHE\n 189:\t\tselect GRO_CELLS\n 190:\t\tdefault n\n 191:\t\n 192:\tconfig NET_IPGRE\n"
}

							input: 31145
							output: 176
							thoughts: 469

**Fuzzing Verdict: Confirmed**

Okay, let's break this down. First, I wanted to confirm the `NET_IPGRE_DEMUX` config option. It's not directly dependent on anything else, but it *is* nested within `net/ipv4/Kconfig` under `menuconfig INET`, which is as expected.

Next, I looked at the `FocusSymbols`. The analysis pointed to these key functions: `pptp_rcv_core`, `pptp_rcv`, `pptp_connect`, `pptp_bind`, `pptp_create`, and `pptp_xmit`. I had to quickly double-check if any of these were static or inlined, since that would affect fuzzing. I confirmed that `pptp_rcv_core` and `pptp_rcv` are static, and the others, `pptp_connect`, `pptp_bind`, `pptp_create`, `pptp_xmit`, are used via function pointers in ops structures. Because of this, the compiler won't be inlining them. This means the list of non-inlined functions to target for fuzzing is: `pptp_rcv_core`, `pptp_rcv`, `pptp_create`, `pptp_connect`, and `pptp_bind`.

I then made sure the `EnableConfigs` list matched the requirements. I've verified that `PPTP`, `PPP`, and `NET_IPGRE_DEMUX` are the correct config flags.

Finally, I reviewed the prompt requirements: the `WorthFuzzing` flag is true, since these changes have a functional impact worth fuzzing. I have a list of non-hot-path kernel functions to focus fuzzing on, and the required enable configs. Everything matches. The data is validated.

Let's call `set-results`.

{
  "EnableConfigs": [
    "PPTP",
    "PPP",
    "NET_IPGRE_DEMUX"
  ],
  "FocusSymbols": [
    "pptp_rcv_core",
    "pptp_rcv",
    "pptp_create",
    "pptp_connect",
    "pptp_bind"
  ],
  "Reasoning": "The patch modifies packet reception parsing and bounds checking logic in pptp_rcv_core() within the PPTP network protocol driver (drivers/net/ppp/pptp.c), ensuring payload availability checks and pskb_may_pull() calls precede header dereferencing to prevent out-of-bounds reads on truncated packets. This is reachable in standard virtualized environments via AF_PPPOX sockets and GRE packet delivery.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "PPTP",
    "PPP",
    "NET_IPGRE_DEMUX"
  ],
  "FocusSymbols": [
    "pptp_rcv_core",
    "pptp_rcv",
    "pptp_create",
    "pptp_connect",
    "pptp_bind"
  ],
  "Reasoning": "The patch modifies packet reception parsing and bounds checking logic in pptp_rcv_core() within the PPTP network protocol driver (drivers/net/ppp/pptp.c), ensuring payload availability checks and pskb_may_pull() calls precede header dereferencing to prevent out-of-bounds reads on truncated packets. This is reachable in standard virtualized environments via AF_PPPOX sockets and GRE packet delivery.",
  "WorthFuzzing": true
}

{
  "WorthFuzzing": true
}

{
  "KMSANReasoning": "The patch addresses bounds checking and skb pull operations in the PPTP receive path (drivers/net/ppp/pptp.c). Specifically, it ensures that adequate payload bytes are available and pulled into the skb linear area before indexing into skb payload offsets (payload[0] through payload[4] and skb-\u003edata[0] through skb-\u003edata[1]).\n\nThese changes prevent out-of-bounds (OOB) memory reads on truncated or malformed network packets. OOB reads and invalid skb buffer dereferences are directly detected by standard KASAN builds. The patch does not introduce new heap/stack allocations, does not copy kernel memory to user space, and does not alter control flow based on uninitialized memory. Therefore, a dedicated KMSAN session is not required.",
  "NeedsKMSAN": false
}

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.

For your convenience, here is the diff of the changes:
commit 215595925f298eef5f22d9c7d28b35122da02c8f
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Sep 2 16:35:00 2026 +0000

    syz-cluster: applied patch under review

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index a797a0606f6b4..4fb94a455c574 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -275,6 +275,7 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
 	struct pppox_sock *po = pppox_sk(sk);
 	struct pptp_opt *opt = &po->proto.pptp;
 	int headersize, payload_len, seq;
+	unsigned int payload_avail;
 	__u8 *payload;
 	struct pptp_gre_header *header;
 
@@ -314,23 +315,34 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
 	if (!pskb_may_pull(skb, headersize + payload_len))
 		goto drop;
 
-	payload = skb->data + headersize;
+	payload_avail = skb->len - headersize;
 	/* check for expected sequence number */
 	if (seq < opt->seq_recv + 1 || WRAPPED(opt->seq_recv, seq)) {
-		if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) &&
-				(PPP_PROTOCOL(payload) == PPP_LCP) &&
-				((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP)))
-			goto allow_packet;
+		if (payload_avail >= PPP_HDRLEN + 1) {
+			if (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1))
+				goto drop;
+
+			payload = skb->data + headersize;
+			if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI &&
+			    PPP_PROTOCOL(payload) == PPP_LCP &&
+			    (payload[4] == PPP_LCP_ECHOREQ || payload[4] == PPP_LCP_ECHOREP))
+				goto allow_packet;
+		}
 	} else {
 		opt->seq_recv = seq;
 allow_packet:
 		skb_pull(skb, headersize);
 
-		if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) {
-			/* chop off address/control */
-			if (skb->len < 3)
+		if (payload_avail >= 2) {
+			if (!pskb_may_pull(skb, 2))
 				goto drop;
-			skb_pull(skb, 2);
+
+			if (skb->data[0] == PPP_ALLSTATIONS && skb->data[1] == PPP_UI) {
+				/* chop off address/control */
+				if (skb->len < 3)
+					goto drop;
+				skb_pull(skb, 2);
+			}
 		}
 
 		skb->ip_summed = CHECKSUM_NONE;

							input: 2699
							output: 38
							thoughts: 132

**Evaluating the Necessity of KMSAN Fuzzing for a PPPTP Patch**

Okay, so I need to decide if this patch in `drivers/net/ppp/pptp.c` warrants a separate KMSAN fuzzing session, beyond the usual KASAN checks. Let's break this down systematically. It's really just software defense and kernel patch review. The severity here is pretty low – just the usual code review and picking the right sanitization tool. No immediate fire drills.

I should examine the patch itself first, and then really dig into the surrounding code in `drivers/net/ppp/pptp.c`. I'll probably start with a quick glance, but if anything looks even slightly suspicious, I'll definitely dive deeper, using `read-file` or `grepper` to get a clearer picture of the function of the code around this patch and the variables being used. This isn't high-stakes, but I want to be thorough. It's all about making an informed decision about allocating resources.

{
  "File": "drivers/net/ppp/pptp.c",
  "FirstLine": 270,
  "LineCount": 90
}

{
  "Contents": " 270:\t\treturn 1;\n 271:\t}\n 272:\t\n 273:\tstatic int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)\n 274:\t{\n 275:\t\tstruct pppox_sock *po = pppox_sk(sk);\n 276:\t\tstruct pptp_opt *opt = \u0026po-\u003eproto.pptp;\n 277:\t\tint headersize, payload_len, seq;\n 278:\t\tunsigned int payload_avail;\n 279:\t\t__u8 *payload;\n 280:\t\tstruct pptp_gre_header *header;\n 281:\t\n 282:\t\tif (!(sk-\u003esk_state \u0026 PPPOX_CONNECTED))\n 283:\t\t\tgoto drop;\n 284:\t\n 285:\t\theader = (struct pptp_gre_header *)(skb-\u003edata);\n 286:\t\theadersize  = sizeof(*header);\n 287:\t\n 288:\t\t/* test if acknowledgement present */\n 289:\t\tif (GRE_IS_ACK(header-\u003egre_hd.flags)) {\n 290:\t\t\t__u32 ack;\n 291:\t\n 292:\t\t\tif (!pskb_may_pull(skb, headersize))\n 293:\t\t\t\tgoto drop;\n 294:\t\t\theader = (struct pptp_gre_header *)(skb-\u003edata);\n 295:\t\n 296:\t\t\t/* ack in different place if S = 0 */\n 297:\t\t\tack = GRE_IS_SEQ(header-\u003egre_hd.flags) ? ntohl(header-\u003eack) :\n 298:\t\t\t\t\t\t\t\t ntohl(header-\u003eseq);\n 299:\t\t\tif (ack \u003e opt-\u003eack_recv)\n 300:\t\t\t\topt-\u003eack_recv = ack;\n 301:\t\t\t/* also handle sequence number wrap-around  */\n 302:\t\t\tif (WRAPPED(ack, opt-\u003eack_recv))\n 303:\t\t\t\topt-\u003eack_recv = ack;\n 304:\t\t} else {\n 305:\t\t\theadersize -= sizeof(header-\u003eack);\n 306:\t\t}\n 307:\t\t/* test if payload present */\n 308:\t\tif (!GRE_IS_SEQ(header-\u003egre_hd.flags))\n 309:\t\t\tgoto drop;\n 310:\t\n 311:\t\tpayload_len = ntohs(header-\u003epayload_len);\n 312:\t\tseq         = ntohl(header-\u003eseq);\n 313:\t\n 314:\t\t/* check for incomplete packet (length smaller than expected) */\n 315:\t\tif (!pskb_may_pull(skb, headersize + payload_len))\n 316:\t\t\tgoto drop;\n 317:\t\n 318:\t\tpayload_avail = skb-\u003elen - headersize;\n 319:\t\t/* check for expected sequence number */\n 320:\t\tif (seq \u003c opt-\u003eseq_recv + 1 || WRAPPED(opt-\u003eseq_recv, seq)) {\n 321:\t\t\tif (payload_avail \u003e= PPP_HDRLEN + 1) {\n 322:\t\t\t\tif (!pskb_may_pull(skb, headersize + PPP_HDRLEN + 1))\n 323:\t\t\t\t\tgoto drop;\n 324:\t\n 325:\t\t\t\tpayload = skb-\u003edata + headersize;\n 326:\t\t\t\tif (payload[0] == PPP_ALLSTATIONS \u0026\u0026 payload[1] == PPP_UI \u0026\u0026\n 327:\t\t\t\t    PPP_PROTOCOL(payload) == PPP_LCP \u0026\u0026\n 328:\t\t\t\t    (payload[4] == PPP_LCP_ECHOREQ || payload[4] == PPP_LCP_ECHOREP))\n 329:\t\t\t\t\tgoto allow_packet;\n 330:\t\t\t}\n 331:\t\t} else {\n 332:\t\t\topt-\u003eseq_recv = seq;\n 333:\tallow_packet:\n 334:\t\t\tskb_pull(skb, headersize);\n 335:\t\n 336:\t\t\tif (payload_avail \u003e= 2) {\n 337:\t\t\t\tif (!pskb_may_pull(skb, 2))\n 338:\t\t\t\t\tgoto drop;\n 339:\t\n 340:\t\t\t\tif (skb-\u003edata[0] == PPP_ALLSTATIONS \u0026\u0026 skb-\u003edata[1] == PPP_UI) {\n 341:\t\t\t\t\t/* chop off address/control */\n 342:\t\t\t\t\tif (skb-\u003elen \u003c 3)\n 343:\t\t\t\t\t\tgoto drop;\n 344:\t\t\t\t\tskb_pull(skb, 2);\n 345:\t\t\t\t}\n 346:\t\t\t}\n 347:\t\n 348:\t\t\tskb-\u003eip_summed = CHECKSUM_NONE;\n 349:\t\t\tskb_set_network_header(skb, skb-\u003ehead-skb-\u003edata);\n 350:\t\t\tppp_input(\u0026po-\u003echan, skb);\n 351:\t\n 352:\t\t\treturn NET_RX_SUCCESS;\n 353:\t\t}\n 354:\tdrop:\n 355:\t\tkfree_skb(skb);\n 356:\t\treturn NET_RX_DROP;\n 357:\t}\n 358:\t\n 359:\tstatic int pptp_rcv(struct sk_buff *skb)\n"
}

							input: 4487
							output: 191
							thoughts: 1096

**Analysis of the PPTP Patch and Sanitizer Selection**

Okay, let's break this down. My initial focus is on the patch within `pptp_rcv_core()` and the bug it's designed to fix. Previously, there was a significant vulnerability: if the incoming packet payload was small, particularly with zero or minimal data, the checks were insufficient. `pskb_may_pull` might succeed, even though accessing `payload[0]` through `payload[4]` would lead to an out-of-bounds read from the skb's linear buffer or unpulled skb data. This is textbook out-of-bounds memory access. The same issue also occurred if `skb_pull` was called, then `payload[0]` was accessed. The patch addresses this directly.

The fix involves two key changes: First, rigorous bounds checks are introduced *before* any access to the `payload` data. This employs a combination of `payload_avail` and more precise calls to `pskb_may_pull` with calculated lengths (`headersize + PPP_HDRLEN + 1`). Second, access to the `skb->data` pointer after `skb_pull` occurs.

Now, let's evaluate which sanitizer is most relevant. Given the nature of the bug, an out-of-bounds read within the skb buffer, the choice is fairly clear. KMSAN is primarily designed to detect uninitialized memory reads. I need to determine if any of those conditions apply here.

1. **Kernel data exposed to userspace?** No. This is incoming packet processing.
2. **Conditional logic based on uninitialized variables?** No. All variables used (payload\_avail, seq, headersize, etc.) are properly initialized.
3. **Complex data structures with initialization issues?** No, the code is relatively straightforward.
4. **Bounds checks leading to uninitialized memory exposure?** No. The data coming from the network is packet data, initialized upon reception.

The bugs are clearly buffer bounds issues – KASAN territory. KMSAN would be irrelevant.

**KASAN vs. KMSAN:**

* **KASAN:** Detects a wide array of memory safety issues, including out-of-bounds access (slab, global, stack), and use-after-free conditions. These are precisely the types of issues we're addressing with the patch's bounds checks.
* **KMSAN:** Targets the detection of uninitialized memory reads. This is not the issue here.

In short, the patch modifies packet parsing in the PPTP network receive path, adding crucial length checks (`pskb_may_pull` and `payload_avail >= ...`) before indexing into the network skb payload buffers. These additions directly address the vulnerability of out-of-bounds buffer reads on short or non-linear skb packets. Since there's no uninitialized kernel memory involved or any of the usual KMSAN concerns, KASAN is the correct sanitizer here. No KMSAN fuzzing is necessary. Therefore, I'm confident in setting `NeedsKMSAN` to `false`. I need to now ensure that my analysis and reasoning are clear.

{
  "KMSANReasoning": "The patch addresses bounds checking and skb pull operations in the PPTP receive path (drivers/net/ppp/pptp.c). Specifically, it ensures that adequate payload bytes are available and pulled into the skb linear area before indexing into skb payload offsets (payload[0] through payload[4] and skb-\u003edata[0] through skb-\u003edata[1]).\n\nThese changes prevent out-of-bounds (OOB) memory reads on truncated or malformed network packets. OOB reads and invalid skb buffer dereferences are directly detected by standard KASAN builds. The patch does not introduce new heap/stack allocations, does not copy kernel memory to user space, and does not alter control flow based on uninitialized memory. Therefore, a dedicated KMSAN session is not required.",
  "NeedsKMSAN": false
}

{
  "KMSANReasoning": "The patch addresses bounds checking and skb pull operations in the PPTP receive path (drivers/net/ppp/pptp.c). Specifically, it ensures that adequate payload bytes are available and pulled into the skb linear area before indexing into skb payload offsets (payload[0] through payload[4] and skb-\u003edata[0] through skb-\u003edata[1]).\n\nThese changes prevent out-of-bounds (OOB) memory reads on truncated or malformed network packets. OOB reads and invalid skb buffer dereferences are directly detected by standard KASAN builds. The patch does not introduce new heap/stack allocations, does not copy kernel memory to user space, and does not alter control flow based on uninitialized memory. Therefore, a dedicated KMSAN session is not required.",
  "NeedsKMSAN": false
}

LLM Calls Summary:
Total Calls	Total Tokens	Avg Tokens	Total Duration (Seconds)	Avg Duration (Seconds)

Tool Calls Summary:
Total Calls	Total Duration (Seconds)	Avg Duration (Seconds)