AI Trajectory

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch modifies a BPF program used by the user-space `perf` tool (located in `tools/perf/`). It does not modify the core kernel, drivers, or architectures that are fuzzed by syzkaller.",
  "WorthFuzzing": false
}

null

{
  "PatchDiff": "commit fb9db2aae29a8e970b7000b7a8f406e34083e923\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Tue Jun 23 13:26:33 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c b/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c\nindex 2a6e61864ee015..6d553ed3ac23c5 100644\n--- a/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c\n+++ b/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c\n@@ -429,15 +429,96 @@ static bool pid_filter__has(struct pids_filtered *pids, pid_t pid)\n \treturn bpf_map_lookup_elem(pids, \u0026pid) != NULL;\n }\n \n+struct args_loop_ctx {\n+\tstruct syscall_enter_args *args;\n+\tunsigned int *beauty_map;\n+\tvoid *payload_offset;\n+\tint value_size;\n+\tu64 *output;\n+\tbool *do_output;\n+};\n+\n+static long process_arg_cb(u64 i, void *ctx)\n+{\n+\t/*\n+\t * Determine what type of argument and how many bytes to read from user space, using the\n+\t * value in the beauty_map. This is the relation of parameter type and its corresponding\n+\t * value in the beauty map, and how many bytes we read eventually:\n+\t *\n+\t * string: 1\t\t\t      -\u003e size of string\n+\t * struct: size of struct\t      -\u003e size of struct\n+\t * buffer: -1 * (index of paired len) -\u003e value of paired len (maximum: TRACE_AUG_MAX_BUF)\n+\t */\n+\tstruct augmented_arg *augmented_arg;\n+\tstruct args_loop_ctx *loop_ctx;\n+\tint aug_size, size, index;\n+\tbool augmented;\n+\tvoid *arg;\n+\n+\t/* Bounds check for the below map access to help the verifier */\n+\tif (i \u003c 0 || i \u003e= 6)\n+\t\treturn 1;\n+\n+\tloop_ctx = (struct args_loop_ctx *)ctx;\n+\targ = (void *)loop_ctx-\u003eargs-\u003eargs[i];\n+\taugmented = false;\n+\tsize = loop_ctx-\u003ebeauty_map[i];\n+\taug_size = size; /* size of the augmented data read from user space */\n+\taugmented_arg = (struct augmented_arg *)loop_ctx-\u003epayload_offset;\n+\n+\tif (size == 0 || arg == NULL)\n+\t\treturn 0; /* continue */\n+\n+\tif (size == 1) { /* string */\n+\t\taug_size = bpf_probe_read_user_str(augmented_arg-\u003evalue, loop_ctx-\u003evalue_size, arg);\n+\t\taugmented = true;\n+\t} else if (size \u003e 0 \u0026\u0026 size \u003c= loop_ctx-\u003evalue_size) { /* struct */\n+\t\tif (!bpf_probe_read_user(augmented_arg-\u003evalue, size, arg))\n+\t\t\taugmented = true;\n+\t} else if (size \u003c 0 \u0026\u0026 size \u003e= -6) { /* buffer */\n+\t\tindex = -(size + 1);\n+\t\tbarrier_var(index); // Prevent clang (noticed with v18) from removing the \u0026= 7 trick.\n+\t\tindex \u0026= 7;\t    // Satisfy the bounds checking with the verifier in some kernels.\n+\t\taug_size = loop_ctx-\u003eargs-\u003eargs[index];\n+\n+\t\tif (aug_size \u003e TRACE_AUG_MAX_BUF)\n+\t\t\taug_size = TRACE_AUG_MAX_BUF;\n+\n+\t\tif (aug_size \u003e 0) {\n+\t\t\tif (!bpf_probe_read_user(augmented_arg-\u003evalue, aug_size, arg))\n+\t\t\t\taugmented = true;\n+\t\t}\n+\t}\n+\n+\t/* Augmented data size is limited to sizeof(augmented_arg-\u003eunnamed union with value field) */\n+\tif (aug_size \u003e loop_ctx-\u003evalue_size)\n+\t\taug_size = loop_ctx-\u003evalue_size;\n+\n+\t/* write data to payload */\n+\tif (augmented) {\n+\t\tint written = offsetof(struct augmented_arg, value) + aug_size;\n+\n+\t\tif (written \u003c 0 || written \u003e sizeof(struct augmented_arg))\n+\t\t\treturn 1; /* break */\n+\n+\t\taugmented_arg-\u003esize = aug_size;\n+\t\t*loop_ctx-\u003eoutput += written;\n+\t\tloop_ctx-\u003epayload_offset += written;\n+\t\t*loop_ctx-\u003edo_output = true;\n+\t}\n+\n+\treturn 0;\n+}\n+\n static int augment_sys_enter(void *ctx, struct syscall_enter_args *args)\n {\n-\tbool augmented, do_output = false;\n-\tint zero = 0, index, value_size = sizeof(struct augmented_arg) - offsetof(struct augmented_arg, value);\n+\tbool do_output = false;\n+\tint zero = 0, value_size = sizeof(struct augmented_arg) - offsetof(struct augmented_arg, value);\n \tu64 output = 0; /* has to be u64, otherwise it won't pass the verifier */\n-\ts64 aug_size, size;\n \tunsigned int nr, *beauty_map;\n \tstruct beauty_payload_enter *payload;\n-\tvoid *arg, *payload_offset;\n+\tvoid *payload_offset;\n+\tlong iters;\n \n \t/* fall back to do predefined tail call */\n \tif (args == NULL)\n@@ -457,63 +538,17 @@ static int augment_sys_enter(void *ctx, struct syscall_enter_args *args)\n \t/* copy the sys_enter header, which has the syscall_nr */\n \t__builtin_memcpy(\u0026payload-\u003eargs, args, sizeof(struct syscall_enter_args));\n \n-\t/*\n-\t * Determine what type of argument and how many bytes to read from user space, using the\n-\t * value in the beauty_map. This is the relation of parameter type and its corresponding\n-\t * value in the beauty map, and how many bytes we read eventually:\n-\t *\n-\t * string: 1\t\t\t      -\u003e size of string\n-\t * struct: size of struct\t      -\u003e size of struct\n-\t * buffer: -1 * (index of paired len) -\u003e value of paired len (maximum: TRACE_AUG_MAX_BUF)\n-\t */\n-\tfor (int i = 0; i \u003c 6; i++) {\n-\t\targ = (void *)args-\u003eargs[i];\n-\t\taugmented = false;\n-\t\tsize = beauty_map[i];\n-\t\taug_size = size; /* size of the augmented data read from user space */\n-\n-\t\tif (size == 0 || arg == NULL)\n-\t\t\tcontinue;\n-\n-\t\tif (size == 1) { /* string */\n-\t\t\taug_size = bpf_probe_read_user_str(((struct augmented_arg *)payload_offset)-\u003evalue, value_size, arg);\n-\t\t\t/* minimum of 0 to pass the verifier */\n-\t\t\tif (aug_size \u003c 0)\n-\t\t\t\taug_size = 0;\n-\n-\t\t\taugmented = true;\n-\t\t} else if (size \u003e 0 \u0026\u0026 size \u003c= value_size) { /* struct */\n-\t\t\tif (!bpf_probe_read_user(((struct augmented_arg *)payload_offset)-\u003evalue, size, arg))\n-\t\t\t\taugmented = true;\n-\t\t} else if ((int)size \u003c 0 \u0026\u0026 size \u003e= -6) { /* buffer */\n-\t\t\tindex = -(size + 1);\n-\t\t\tbarrier_var(index); // Prevent clang (noticed with v18) from removing the \u0026= 7 trick.\n-\t\t\tindex \u0026= 7;\t    // Satisfy the bounds checking with the verifier in some kernels.\n-\t\t\taug_size = args-\u003eargs[index] \u003e TRACE_AUG_MAX_BUF ? TRACE_AUG_MAX_BUF : args-\u003eargs[index];\n-\n-\t\t\tif (aug_size \u003e 0) {\n-\t\t\t\tif (!bpf_probe_read_user(((struct augmented_arg *)payload_offset)-\u003evalue, aug_size, arg))\n-\t\t\t\t\taugmented = true;\n-\t\t\t}\n-\t\t}\n-\n-\t\t/* Augmented data size is limited to sizeof(augmented_arg-\u003eunnamed union with value field) */\n-\t\tif (aug_size \u003e value_size)\n-\t\t\taug_size = value_size;\n-\n-\t\t/* write data to payload */\n-\t\tif (augmented) {\n-\t\t\tint written = offsetof(struct augmented_arg, value) + aug_size;\n-\n-\t\t\tif (written \u003c 0 || written \u003e sizeof(struct augmented_arg))\n-\t\t\t\treturn 1;\n-\n-\t\t\t((struct augmented_arg *)payload_offset)-\u003esize = aug_size;\n-\t\t\toutput += written;\n-\t\t\tpayload_offset += written;\n-\t\t\tdo_output = true;\n-\t\t}\n-\t}\n+\tstruct args_loop_ctx loop_ctx = {\n+\t\t.args = args,\n+\t\t.beauty_map = beauty_map,\n+\t\t.payload_offset = payload_offset,\n+\t\t.value_size = value_size,\n+\t\t.output = \u0026output,\n+\t\t.do_output = \u0026do_output\n+\t};\n+\titers = bpf_loop(6, process_arg_cb, \u0026loop_ctx, 0);\n+\tif (iters != 6)\n+\t\treturn 1;\n \n \tif (!do_output || (sizeof(struct syscall_enter_args) + output) \u003e sizeof(struct beauty_payload_enter))\n \t\treturn 1;\n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch modifies a BPF program used by the user-space `perf` tool (located in `tools/perf/`). It does not modify the core kernel, drivers, or architectures that are fuzzed by syzkaller.",
  "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 fb9db2aae29a8e970b7000b7a8f406e34083e923
Author: syz-cluster <triage@syzkaller.com>
Date:   Tue Jun 23 13:26:33 2026 +0000

    syz-cluster: applied patch under review

diff --git a/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c b/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c
index 2a6e61864ee015..6d553ed3ac23c5 100644
--- a/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c
+++ b/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c
@@ -429,15 +429,96 @@ static bool pid_filter__has(struct pids_filtered *pids, pid_t pid)
 	return bpf_map_lookup_elem(pids, &pid) != NULL;
 }
 
+struct args_loop_ctx {
+	struct syscall_enter_args *args;
+	unsigned int *beauty_map;
+	void *payload_offset;
+	int value_size;
+	u64 *output;
+	bool *do_output;
+};
+
+static long process_arg_cb(u64 i, void *ctx)
+{
+	/*
+	 * Determine what type of argument and how many bytes to read from user space, using the
+	 * value in the beauty_map. This is the relation of parameter type and its corresponding
+	 * value in the beauty map, and how many bytes we read eventually:
+	 *
+	 * string: 1			      -> size of string
+	 * struct: size of struct	      -> size of struct
+	 * buffer: -1 * (index of paired len) -> value of paired len (maximum: TRACE_AUG_MAX_BUF)
+	 */
+	struct augmented_arg *augmented_arg;
+	struct args_loop_ctx *loop_ctx;
+	int aug_size, size, index;
+	bool augmented;
+	void *arg;
+
+	/* Bounds check for the below map access to help the verifier */
+	if (i < 0 || i >= 6)
+		return 1;
+
+	loop_ctx = (struct args_loop_ctx *)ctx;
+	arg = (void *)loop_ctx->args->args[i];
+	augmented = false;
+	size = loop_ctx->beauty_map[i];
+	aug_size = size; /* size of the augmented data read from user space */
+	augmented_arg = (struct augmented_arg *)loop_ctx->payload_offset;
+
+	if (size == 0 || arg == NULL)
+		return 0; /* continue */
+
+	if (size == 1) { /* string */
+		aug_size = bpf_probe_read_user_str(augmented_arg->value, loop_ctx->value_size, arg);
+		augmented = true;
+	} else if (size > 0 && size <= loop_ctx->value_size) { /* struct */
+		if (!bpf_probe_read_user(augmented_arg->value, size, arg))
+			augmented = true;
+	} else if (size < 0 && size >= -6) { /* buffer */
+		index = -(size + 1);
+		barrier_var(index); // Prevent clang (noticed with v18) from removing the &= 7 trick.
+		index &= 7;	    // Satisfy the bounds checking with the verifier in some kernels.
+		aug_size = loop_ctx->args->args[index];
+
+		if (aug_size > TRACE_AUG_MAX_BUF)
+			aug_size = TRACE_AUG_MAX_BUF;
+
+		if (aug_size > 0) {
+			if (!bpf_probe_read_user(augmented_arg->value, aug_size, arg))
+				augmented = true;
+		}
+	}
+
+	/* Augmented data size is limited to sizeof(augmented_arg->unnamed union with value field) */
+	if (aug_size > loop_ctx->value_size)
+		aug_size = loop_ctx->value_size;
+
+	/* write data to payload */
+	if (augmented) {
+		int written = offsetof(struct augmented_arg, value) + aug_size;
+
+		if (written < 0 || written > sizeof(struct augmented_arg))
+			return 1; /* break */
+
+		augmented_arg->size = aug_size;
+		*loop_ctx->output += written;
+		loop_ctx->payload_offset += written;
+		*loop_ctx->do_output = true;
+	}
+
+	return 0;
+}
+
 static int augment_sys_enter(void *ctx, struct syscall_enter_args *args)
 {
-	bool augmented, do_output = false;
-	int zero = 0, index, value_size = sizeof(struct augmented_arg) - offsetof(struct augmented_arg, value);
+	bool do_output = false;
+	int zero = 0, value_size = sizeof(struct augmented_arg) - offsetof(struct augmented_arg, value);
 	u64 output = 0; /* has to be u64, otherwise it won't pass the verifier */
-	s64 aug_size, size;
 	unsigned int nr, *beauty_map;
 	struct beauty_payload_enter *payload;
-	void *arg, *payload_offset;
+	void *payload_offset;
+	long iters;
 
 	/* fall back to do predefined tail call */
 	if (args == NULL)
@@ -457,63 +538,17 @@ static int augment_sys_enter(void *ctx, struct syscall_enter_args *args)
 	/* copy the sys_enter header, which has the syscall_nr */
 	__builtin_memcpy(&payload->args, args, sizeof(struct syscall_enter_args));
 
-	/*
-	 * Determine what type of argument and how many bytes to read from user space, using the
-	 * value in the beauty_map. This is the relation of parameter type and its corresponding
-	 * value in the beauty map, and how many bytes we read eventually:
-	 *
-	 * string: 1			      -> size of string
-	 * struct: size of struct	      -> size of struct
-	 * buffer: -1 * (index of paired len) -> value of paired len (maximum: TRACE_AUG_MAX_BUF)
-	 */
-	for (int i = 0; i < 6; i++) {
-		arg = (void *)args->args[i];
-		augmented = false;
-		size = beauty_map[i];
-		aug_size = size; /* size of the augmented data read from user space */
-
-		if (size == 0 || arg == NULL)
-			continue;
-
-		if (size == 1) { /* string */
-			aug_size = bpf_probe_read_user_str(((struct augmented_arg *)payload_offset)->value, value_size, arg);
-			/* minimum of 0 to pass the verifier */
-			if (aug_size < 0)
-				aug_size = 0;
-
-			augmented = true;
-		} else if (size > 0 && size <= value_size) { /* struct */
-			if (!bpf_probe_read_user(((struct augmented_arg *)payload_offset)->value, size, arg))
-				augmented = true;
-		} else if ((int)size < 0 && size >= -6) { /* buffer */
-			index = -(size + 1);
-			barrier_var(index); // Prevent clang (noticed with v18) from removing the &= 7 trick.
-			index &= 7;	    // Satisfy the bounds checking with the verifier in some kernels.
-			aug_size = args->args[index] > TRACE_AUG_MAX_BUF ? TRACE_AUG_MAX_BUF : args->args[index];
-
-			if (aug_size > 0) {
-				if (!bpf_probe_read_user(((struct augmented_arg *)payload_offset)->value, aug_size, arg))
-					augmented = true;
-			}
-		}
-
-		/* Augmented data size is limited to sizeof(augmented_arg->unnamed union with value field) */
-		if (aug_size > value_size)
-			aug_size = value_size;
-
-		/* write data to payload */
-		if (augmented) {
-			int written = offsetof(struct augmented_arg, value) + aug_size;
-
-			if (written < 0 || written > sizeof(struct augmented_arg))
-				return 1;
-
-			((struct augmented_arg *)payload_offset)->size = aug_size;
-			output += written;
-			payload_offset += written;
-			do_output = true;
-		}
-	}
+	struct args_loop_ctx loop_ctx = {
+		.args = args,
+		.beauty_map = beauty_map,
+		.payload_offset = payload_offset,
+		.value_size = value_size,
+		.output = &output,
+		.do_output = &do_output
+	};
+	iters = bpf_loop(6, process_arg_cb, &loop_ctx, 0);
+	if (iters != 6)
+		return 1;
 
 	if (!do_output || (sizeof(struct syscall_enter_args) + output) > sizeof(struct beauty_payload_enter))
 		return 1;

gemini-3.1-pro-preview

null

null

							input: 3991
							output: 79
							thoughts: 586
						

**Analysis of the Patch: WorthFuzzing=false**

Okay, let's break this down. We have a patch that's modifying `tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c`. My initial thought is, "This looks like BPF code, and BPF runs in the kernel, so could this be a fuzzing target for syzkaller?" We're replacing a `for` loop with `bpf_loop` and a callback, a standard optimization within BPF programs used by `perf`.

But hold on, this code isn't *directly* part of the kernel image. It's user-space code within the `perf` tool, even though it *is* BPF code that gets loaded into the kernel by `perf`. Syzkaller fuzzes the kernel, and it can load BPF programs, but it generates its *own* BPF programs to test the kernel's syscall interface. It doesn't target code that's *part* of a user-space tool like `perf`.

I need to confirm this understanding. The `tools/` directory is typically a sign of user-space code. Syzkaller doesn't fuzz the `perf` tool itself; it fuzzes the kernel. So, the fact that the patch lives in `tools/perf/` is a key indicator.

Therefore, this patch *doesn't* modify the kernel in a way that syzkaller would directly fuzz. The BPF program is loaded by the `perf` tool; it is not kernel code as such. It's a tool-specific BPF program.

I'm confident in saying that `WorthFuzzing=false`. The reasoning is clear: this patch is confined to the user-space `perf` tool and its BPF program, not the core kernel components, drivers, or architectures that syzkaller targets.

I double-checked to make sure. I've verified that the diff is entirely contained within `tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c`. There's nothing else to consider.

I will call `set-results` with `WorthFuzzing=false`.

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch modifies a BPF program used by the user-space `perf` tool (located in `tools/perf/`). It does not modify the core kernel, drivers, or architectures that are fuzzed by syzkaller.",
  "WorthFuzzing": false
}

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch modifies a BPF program used by the user-space `perf` tool (located in `tools/perf/`). It does not modify the core kernel, drivers, or architectures that are fuzzed by syzkaller.",
  "WorthFuzzing": false
}