AI Trajectory

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies a selftest (tools/testing/selftests/net/mptcp/mptcp_diag.c), not the kernel code itself. Therefore, it does not require kernel fuzzing.",
  "WorthFuzzing": false
}

null

{
  "PatchDiff": "commit 8cb5b13b9880d35fa61a09f4d9e506399a7dc3f5\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Wed Jul 1 16:49:01 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c\nindex 5e222ba977e4e9..02ac93f794fea7 100644\n--- a/tools/testing/selftests/net/mptcp/mptcp_diag.c\n+++ b/tools/testing/selftests/net/mptcp/mptcp_diag.c\n@@ -377,7 +377,7 @@ static void get_subflow_info(char *subflow_addrs)\n \tint ret;\n \tint fd;\n \n-\tret = sscanf(subflow_addrs, \"%[^:]:%d %[^:]:%d\", saddr, \u0026sport, daddr, \u0026dport);\n+\tret = sscanf(subflow_addrs, \"%63[^:]:%d %63[^:]:%d\", saddr, \u0026sport, daddr, \u0026dport);\n \tif (ret != 4)\n \t\tdie_perror(\"IP PORT Pairs has style problems!\");\n \n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies a selftest (tools/testing/selftests/net/mptcp/mptcp_diag.c), not the kernel code itself. Therefore, it does not require kernel fuzzing.",
  "WorthFuzzing": false
}

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 8cb5b13b9880d35fa61a09f4d9e506399a7dc3f5
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Jul 1 16:49:01 2026 +0000

    syz-cluster: applied patch under review

diff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c
index 5e222ba977e4e9..02ac93f794fea7 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_diag.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_diag.c
@@ -377,7 +377,7 @@ static void get_subflow_info(char *subflow_addrs)
 	int ret;
 	int fd;
 
-	ret = sscanf(subflow_addrs, "%[^:]:%d %[^:]:%d", saddr, &sport, daddr, &dport);
+	ret = sscanf(subflow_addrs, "%63[^:]:%d %63[^:]:%d", saddr, &sport, daddr, &dport);
 	if (ret != 4)
 		die_perror("IP PORT Pairs has style problems!");
 

gemini-3.1-pro-preview

null

null

							input: 1909
							output: 77
							thoughts: 100
						

**My Assessment of the Patch's Worthiness for Fuzzing**

Okay, so I've taken a look at this patch. It's touching `tools/testing/selftests/net/mptcp/mptcp_diag.c`, specifically. The change itself is pretty straightforward: they're hardening a `sscanf` call by adding a length limit to the format string (`%63[^:]`). This is a standard and commendable practice, I'll give them that.

However, and this is the crux of it for my analysis, this modification is *within* the selftests infrastructure. It's not in any of the core kernel code, just the test suite. Given my expertise, I have to conclude that because this is a change within the testing framework, it's irrelevant to the kernel fuzzer's goals. My whole focus is on finding vulnerabilities in the kernel itself. Running this would be a waste of resources.

Therefore, my recommendation is clear: `WorthFuzzing=false`. This one's a no-go for fuzzing.

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies a selftest (tools/testing/selftests/net/mptcp/mptcp_diag.c), not the kernel code itself. Therefore, it does not require kernel fuzzing.",
  "WorthFuzzing": false
}

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only modifies a selftest (tools/testing/selftests/net/mptcp/mptcp_diag.c), not the kernel code itself. Therefore, it does not require kernel fuzzing.",
  "WorthFuzzing": false
}