AI Trajectory

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only replaces a WARN_ON with a pr_err and moves a helper function to avoid a forward declaration. It does not make any functional changes to the kernel execution flow that should be fuzzed.",
  "WorthFuzzing": false
}

null

{
  "PatchDiff": "commit 5382269cb48fc26b2a3d7a6ebcdaec19874d342c\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Fri Jul 31 16:07:51 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c\nindex 99801e844b305..a7c57cc81fb3f 100644\n--- a/arch/x86/kernel/cpu/cpuid-deps.c\n+++ b/arch/x86/kernel/cpu/cpuid-deps.c\n@@ -114,6 +114,21 @@ static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)\n /* Take the capabilities and the BUG bits into account */\n #define MAX_FEATURE_BITS ((NCAPINTS + NBUGINTS) * sizeof(u32) * 8)\n \n+/*\n+ * Return the feature \"name\" if available, otherwise return\n+ * the X86_FEATURE_* numerals to make it easier to identify\n+ * the feature.\n+ */\n+static const char *x86_feature_name(unsigned int feature, char *buf)\n+{\n+\tif (x86_cap_flags[feature])\n+\t\treturn x86_cap_flags[feature];\n+\n+\tsnprintf(buf, 16, \"%d*32+%2d\", feature / 32, feature % 32);\n+\n+\treturn buf;\n+}\n+\n static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)\n {\n \tDECLARE_BITMAP(disable, MAX_FEATURE_BITS);\n@@ -123,8 +138,12 @@ static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)\n \tif (WARN_ON(feature \u003e= MAX_FEATURE_BITS))\n \t\treturn;\n \n-\tif (boot_cpu_has(feature))\n-\t\tWARN_ON(alternatives_patched);\n+\tif (boot_cpu_has(feature) \u0026\u0026 alternatives_patched) {\n+\t\tchar feature_buf[16];\n+\n+\t\tpr_err(\"x86/cpu: CPU feature %s cleared after alternatives patched\\n\",\n+\t\t       x86_feature_name(feature, feature_buf));\n+\t}\n \n \tclear_feature(c, feature);\n \n@@ -157,21 +176,6 @@ void setup_clear_cpu_cap(unsigned int feature)\n \tdo_clear_cpu_cap(NULL, feature);\n }\n \n-/*\n- * Return the feature \"name\" if available, otherwise return\n- * the X86_FEATURE_* numerals to make it easier to identify\n- * the feature.\n- */\n-static const char *x86_feature_name(unsigned int feature, char *buf)\n-{\n-\tif (x86_cap_flags[feature])\n-\t\treturn x86_cap_flags[feature];\n-\n-\tsnprintf(buf, 16, \"%d*32+%2d\", feature / 32, feature % 32);\n-\n-\treturn buf;\n-}\n-\n void check_cpufeature_deps(struct cpuinfo_x86 *c)\n {\n \tchar feature_buf[16], depends_buf[16];\n"
}

best-expensive

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only replaces a WARN_ON with a pr_err and moves a helper function to avoid a forward declaration. It does not make any functional changes to the kernel execution flow that should be fuzzed.",
  "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).
- 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 5382269cb48fc26b2a3d7a6ebcdaec19874d342c
Author: syz-cluster <triage@syzkaller.com>
Date:   Fri Jul 31 16:07:51 2026 +0000

    syz-cluster: applied patch under review

diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index 99801e844b305..a7c57cc81fb3f 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -114,6 +114,21 @@ static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)
 /* Take the capabilities and the BUG bits into account */
 #define MAX_FEATURE_BITS ((NCAPINTS + NBUGINTS) * sizeof(u32) * 8)
 
+/*
+ * Return the feature "name" if available, otherwise return
+ * the X86_FEATURE_* numerals to make it easier to identify
+ * the feature.
+ */
+static const char *x86_feature_name(unsigned int feature, char *buf)
+{
+	if (x86_cap_flags[feature])
+		return x86_cap_flags[feature];
+
+	snprintf(buf, 16, "%d*32+%2d", feature / 32, feature % 32);
+
+	return buf;
+}
+
 static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
 {
 	DECLARE_BITMAP(disable, MAX_FEATURE_BITS);
@@ -123,8 +138,12 @@ static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
 	if (WARN_ON(feature >= MAX_FEATURE_BITS))
 		return;
 
-	if (boot_cpu_has(feature))
-		WARN_ON(alternatives_patched);
+	if (boot_cpu_has(feature) && alternatives_patched) {
+		char feature_buf[16];
+
+		pr_err("x86/cpu: CPU feature %s cleared after alternatives patched\n",
+		       x86_feature_name(feature, feature_buf));
+	}
 
 	clear_feature(c, feature);
 
@@ -157,21 +176,6 @@ void setup_clear_cpu_cap(unsigned int feature)
 	do_clear_cpu_cap(NULL, feature);
 }
 
-/*
- * Return the feature "name" if available, otherwise return
- * the X86_FEATURE_* numerals to make it easier to identify
- * the feature.
- */
-static const char *x86_feature_name(unsigned int feature, char *buf)
-{
-	if (x86_cap_flags[feature])
-		return x86_cap_flags[feature];
-
-	snprintf(buf, 16, "%d*32+%2d", feature / 32, feature % 32);
-
-	return buf;
-}
-
 void check_cpufeature_deps(struct cpuinfo_x86 *c)
 {
 	char feature_buf[16], depends_buf[16];

gemini-3.1-pro-preview

null

null

							input: 2631
							output: 75
							thoughts: 266
						

**My Assessment of the Patch**

Okay, so I'm looking at this patch for `arch/x86/kernel/cpu/cpuid-deps.c`. It's a simple one, really. They've moved the `x86_feature_name` function up in the file, which is just for code organization, probably to avoid a forward declaration. The core change is in `do_clear_cpu_cap`. It used to just `WARN_ON(alternatives_patched)` if a feature was set on boot and alternatives had been patched. Now, it uses `x86_feature_name` to construct a more informative error message with `pr_err`. The diff makes it clear, it's just a `WARN_ON` replacement with a more descriptive `pr_err`.

So, the change is purely about logging and error messaging. There are no modifications to the kernel's execution flow that I can see. This isn't something that would expose new vulnerabilities or areas that benefit from fuzzing. It's safe to say this patch can be classified as not worthy of fuzzing.
Therefore, my recommendation is `WorthFuzzing=false`.

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch only replaces a WARN_ON with a pr_err and moves a helper function to avoid a forward declaration. It does not make any functional changes to the kernel execution flow that should be fuzzed.",
  "WorthFuzzing": false
}

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only replaces a WARN_ON with a pr_err and moves a helper function to avoid a forward declaration. It does not make any functional changes to the kernel execution flow that should be fuzzed.",
  "WorthFuzzing": false
}