AI Trajectory

null

{
  "EnableConfigs": [
    "IP_SCTP"
  ],
  "FocusSymbols": [
    "sctp_process_strreset_inreq"
  ],
  "Reasoning": "The patch adds a bounds check to `sctp_process_strreset_inreq` in the SCTP protocol implementation to prevent an oversized chunk creation or buffer overflow when processing stream reset requests. This is a functional change in network packet processing logic that is reachable and should be fuzzed.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 70cb0d80db3ae63be2f12417a564fe9918abd1a2\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Wed Jul 8 07:18:18 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/sctp/stream.c b/net/sctp/stream.c\nindex 5c2fdedea088ff..ea3805712b7621 100644\n--- a/net/sctp/stream.c\n+++ b/net/sctp/stream.c\n@@ -639,6 +639,10 @@ struct sctp_chunk *sctp_process_strreset_inreq(\n \n \tnums = (ntohs(param.p-\u003elength) - sizeof(*inreq)) / sizeof(__u16);\n \tstr_p = inreq-\u003elist_of_streams;\n+\tif (nums * sizeof(__u16) + sizeof(struct sctp_strreset_outreq)\n+\t\t\t\u003e SCTP_MAX_CHUNK_LEN - sizeof(struct sctp_reconf_chunk)) {\n+\t\tgoto out;\n+\t}\n \tfor (i = 0; i \u003c nums; i++) {\n \t\tif (ntohs(str_p[i]) \u003e= stream-\u003eoutcnt) {\n \t\t\tresult = SCTP_STRRESET_ERR_WRONG_SSN;\n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": [
    "IP_SCTP"
  ],
  "FocusSymbols": [
    "sctp_process_strreset_inreq"
  ],
  "Reasoning": "The patch adds a bounds check to `sctp_process_strreset_inreq` in the SCTP protocol implementation to prevent an oversized chunk creation or buffer overflow when processing stream reset requests. This is a functional change in network packet processing logic that is reachable and should be fuzzed.",
  "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).

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.
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.
   Do not list too generic configs (we already have them enabled). Only list those that
   specifically cover the modified code. 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 70cb0d80db3ae63be2f12417a564fe9918abd1a2
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Jul 8 07:18:18 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 5c2fdedea088ff..ea3805712b7621 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -639,6 +639,10 @@ struct sctp_chunk *sctp_process_strreset_inreq(
 
 	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
 	str_p = inreq->list_of_streams;
+	if (nums * sizeof(__u16) + sizeof(struct sctp_strreset_outreq)
+			> SCTP_MAX_CHUNK_LEN - sizeof(struct sctp_reconf_chunk)) {
+		goto out;
+	}
 	for (i = 0; i < nums; i++) {
 		if (ntohs(str_p[i]) >= stream->outcnt) {
 			result = SCTP_STRRESET_ERR_WRONG_SSN;

gemini-3.1-pro-preview

null

null

							input: 1909
							output: 40
							thoughts: 202
						

**Analyzing the SCTP Stream Reset Patch**

Okay, so I'm looking at this patch for `net/sctp/stream.c`. The core of the change seems to be in the `sctp_process_strreset_inreq` function. It's adding a crucial size check, and it's functional, which is what I like to see.

It looks like the intent is to prevent a buffer overflow or the creation of an overly large chunk during stream reset processing. Specifically, the code calculates `nums`, which appears to represent the number of streams being reset, and then multiplies it by `sizeof(__u16)` to determine the total size of the stream list. That calculation is then compared against a maximum size, considering the overhead of `struct sctp_strreset_outreq` and a reconfig chunk.

Essentially, they're guarding against a situation where a malicious or erroneous peer sends a Stream Reset request with an excessively long stream list. If the calculated size exceeds the maximum, the request is rejected by jumping to `out`, presumably preventing the allocation of an excessively large buffer or chunk. Smart. This is a good sanity check to have in place and addresses a potential vulnerability. I'll need to dig deeper into the actual constants `SCTP_MAX_CHUNK_LEN` and `sizeof(struct sctp_reconf_chunk)` to understand the exact limits being imposed, but the approach is sound. Let me verify the rest of `sctp_process_strreset_inreq` to get a more complete view.

{
  "Expression": "sctp_process_strreset_inreq",
  "PathPrefix": "net/sctp/stream.c"
}

{
  "Output": "net/sctp/stream.c=516=struct sctp_chunk *sctp_process_strreset_outreq(\n--\nnet/sctp/stream.c-604-\nnet/sctp/stream.c:605:struct sctp_chunk *sctp_process_strreset_inreq(\nnet/sctp/stream.c-606-\t\t\t\tstruct sctp_association *asoc,\n"
}

gemini-3.1-pro-preview

null

null

							input: 2605
							output: 34
							thoughts: 10
						

Okay, here's my attempt at summarizing that thought process, keeping in mind I'm speaking to an expert:

**Investigating SCTP Configuration**

Alright, so the task at hand is to figure out the current configuration settings that govern Stream Control Transmission Protocol (SCTP) in this system. I need to understand what's enabled, disabled, and what parameters might be set. This isn't necessarily a deep dive into SCTP's intricacies, but a quick inventory of how it's *being* used right now. I'm thinking I'll start by looking at the standard configuration files, potentially system-wide or within the relevant application. My goal is to quickly pinpoint the key settings that control SCTP behavior and availability. No need for a comprehensive treatise on SCTP itself; just a map of the current state of play in *this* deployment.

{
  "Expression": "config IP_SCTP",
  "PathPrefix": "net/sctp/Kconfig"
}

{
  "Output": "net/sctp/Kconfig-5-\nnet/sctp/Kconfig:6:menuconfig IP_SCTP\nnet/sctp/Kconfig-7-\ttristate \"The SCTP Protocol\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 2896
							output: 37
							thoughts: 63
						

Okay, here's my take on those thoughts, framed as my own mental processing:

**Analyzing the SCTP Stream Reset Request Processing**

Alright, so we're looking at `IP_SCTP` – that's the key config. We're zeroing in on the `sctp_process_strreset_inreq` function. It’s the one handling those incoming stream reset requests in SCTP. Yep, that's definitely a viable target for fuzzing. It's almost guaranteed to be reachable, making it a good candidate for our work. Before we dive into fuzzing, I should probably double-check if any other configurations might be relevant, just to make sure we're not missing anything obvious that could affect our approach. Best to be thorough.

{
  "Expression": "sctp_process_strreset_inreq",
  "PathPrefix": "net/sctp/"
}

{
  "Output": "net/sctp/sm_statefuns.c=4165=enum sctp_disposition sctp_sf_do_reconf(struct net *net,\n--\nnet/sctp/sm_statefuns.c-4200-\t\telse if (param.p-\u003etype == SCTP_PARAM_RESET_IN_REQUEST)\nnet/sctp/sm_statefuns.c:4201:\t\t\treply = sctp_process_strreset_inreq(\nnet/sctp/sm_statefuns.c-4202-\t\t\t\t(struct sctp_association *)asoc, param, \u0026ev);\n--\nnet/sctp/stream.c=516=struct sctp_chunk *sctp_process_strreset_outreq(\n--\nnet/sctp/stream.c-604-\nnet/sctp/stream.c:605:struct sctp_chunk *sctp_process_strreset_inreq(\nnet/sctp/stream.c-606-\t\t\t\tstruct sctp_association *asoc,\n"
}

gemini-3.1-pro-preview

null

null

							input: 3445
							output: 112
							thoughts: 37
						

Okay, here's my take on those thoughts, framed as an expert's inner monologue:

**Focusing on SCTP Stream Reset**

Alright, the context is clearly the `IP_SCTP` configuration, meaning we're dealing with Stream Control Transmission Protocol over IP. My immediate focus needs to be on the `sctp_process_strreset_inreq` function. I've got a stream reset request coming in, and that means a specific state transition, data retransmission management, and potential resource cleanup are all in play. Now it's time to map the functionality to the response and prepare the results.

{
  "EnableConfigs": [
    "IP_SCTP"
  ],
  "FocusSymbols": [
    "sctp_process_strreset_inreq"
  ],
  "Reasoning": "The patch adds a bounds check to `sctp_process_strreset_inreq` in the SCTP protocol implementation to prevent an oversized chunk creation or buffer overflow when processing stream reset requests. This is a functional change in network packet processing logic that is reachable and should be fuzzed.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "IP_SCTP"
  ],
  "FocusSymbols": [
    "sctp_process_strreset_inreq"
  ],
  "Reasoning": "The patch adds a bounds check to `sctp_process_strreset_inreq` in the SCTP protocol implementation to prevent an oversized chunk creation or buffer overflow when processing stream reset requests. This is a functional change in network packet processing logic that is reachable and should be fuzzed.",
  "WorthFuzzing": true
}