AI Trajectory

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "KMSANReasoning": "",
  "NeedsKMSAN": false,
  "Reasoning": "The patch only adds rate-limited informational/error logging (pr_err_ratelimited) to record memcg v1 userspace OOM wait entry and completion statistics. It does not alter control flow, locking, or kernel data structures, and introduces no new assertions or logic. Therefore, it constitutes purely decorative logging and does not warrant fuzzing.",
  "WorthFuzzing": false
}

null

{
  "PatchDiff": "commit b11677392f789134cbe7c45913f159c902145c2c\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Tue Oct 13 05:14:56 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c\nindex 05ef55cae4dc6..7832ce11f4312 100644\n--- a/mm/memcontrol-v1.c\n+++ b/mm/memcontrol-v1.c\n@@ -91,6 +91,12 @@ struct mem_cgroup_event {\n #define MEMFILE_TYPE(val)\t((val) \u003e\u003e 16 \u0026 0xffff)\n #define MEMFILE_ATTR(val)\t((val) \u0026 0xffff)\n \n+#define MEMCG_OOM_WAIT_PATH_LEN\t\t128\n+#define MEMCG_OOM_STAGE_ENTER\t\t\"enter\"\n+#define MEMCG_OOM_STAGE_RECOVERED\t\"recovered\"\n+#define MEMCG_OOM_STAGE_KILLED\t\t\"killed\"\n+#define MEMCG_OOM_UNKNOWN_PATH\t\t\"\u003cunknown\u003e\"\n+\n enum {\n \tRES_USAGE,\n \tRES_LIMIT,\n@@ -1372,6 +1378,34 @@ void memcg1_oom_recover(struct mem_cgroup *memcg)\n \t\t__wake_up(\u0026memcg_oom_waitq, TASK_NORMAL, 0, memcg);\n }\n \n+/**\n+ * memcg1_log_oom_wait - Log memcg userspace OOM wait entry and completion\n+ * @memcg: The memory cgroup experiencing the userspace OOM wait\n+ * @stage: Lifecycle stage string (\"enter\", \"recovered\", or \"killed\")\n+ * @waited_ms: Elapsed time spent waiting on memcg_oom_waitq in milliseconds\n+ * @killed: Whether the waiting task woke with a fatal signal pending\n+ *\n+ * Emits a rate-limited KERN_ERR message so that memcg userspace OOM handler\n+ * stalls are captured on serial consoles even when booted with quiet\n+ * (console_loglevel=4) and preserved in dmesg.\n+ */\n+static void memcg1_log_oom_wait(struct mem_cgroup *memcg, const char *stage,\n+\t\t\t\tunsigned int waited_ms, bool killed)\n+{\n+\tchar cgrp_path[MEMCG_OOM_WAIT_PATH_LEN];\n+\tu64 usage_kb = K((u64)page_counter_read(\u0026memcg-\u003ememory));\n+\tu64 limit_kb = K((u64)READ_ONCE(memcg-\u003ememory.max));\n+\tu64 unevictable_kb = K((u64)memcg_page_state(memcg, NR_UNEVICTABLE));\n+\n+\tif (cgroup_path(memcg-\u003ecss.cgroup, cgrp_path, sizeof(cgrp_path)) \u003c 0)\n+\t\tstrscpy(cgrp_path, MEMCG_OOM_UNKNOWN_PATH, sizeof(cgrp_path));\n+\n+\tpr_err_ratelimited(\"memcg_oom_wait: stage=%s cgroup=%s comm=%s pid=%d usage_kb=%llu limit_kb=%llu unevictable_kb=%llu waited_ms=%u killed=%d\\n\",\n+\t\t\t   stage, cgrp_path, current-\u003ecomm, current-\u003epid,\n+\t\t\t   usage_kb, limit_kb, unevictable_kb,\n+\t\t\t   waited_ms, killed);\n+}\n+\n /**\n  * mem_cgroup_oom_synchronize - complete memcg OOM handling\n  * @handle: actually kill/wait or just clean up the OOM state\n@@ -1393,6 +1427,7 @@ bool mem_cgroup_oom_synchronize(bool handle)\n {\n \tstruct mem_cgroup *memcg = current-\u003ememcg_in_oom;\n \tstruct oom_wait_info owait;\n+\tunsigned long start_jiffies = 0;\n \tbool locked;\n \n \t/* OOM is global, do not handle */\n@@ -1413,10 +1448,22 @@ bool mem_cgroup_oom_synchronize(bool handle)\n \n \tlocked = mem_cgroup_oom_trylock(memcg);\n \n-\tif (locked)\n+\tif (locked) {\n+\t\tstart_jiffies = jiffies;\n+\t\tmemcg1_log_oom_wait(memcg, MEMCG_OOM_STAGE_ENTER, 0, false);\n \t\tmem_cgroup_oom_notify(memcg);\n+\t}\n \n \tschedule();\n+\tif (locked) {\n+\t\tbool killed = fatal_signal_pending(current);\n+\n+\t\tmemcg1_log_oom_wait(memcg,\n+\t\t\t\t    killed ? MEMCG_OOM_STAGE_KILLED :\n+\t\t\t\t\t     MEMCG_OOM_STAGE_RECOVERED,\n+\t\t\t\t    jiffies_to_msecs(jiffies - start_jiffies),\n+\t\t\t\t    killed);\n+\t}\n \tmem_cgroup_unmark_under_oom(memcg);\n \tfinish_wait(\u0026memcg_oom_waitq, \u0026owait.wait);\n \n"
}

core

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only adds rate-limited informational/error logging (pr_err_ratelimited) to record memcg v1 userspace OOM wait entry and completion statistics. It does not alter control flow, locking, or kernel data structures, and introduces no new assertions or logic. Therefore, it constitutes purely decorative logging and does not warrant fuzzing.",
  "WorthFuzzing": false
}

You are an expert Linux kernel maintainer and security engineer.
Your job is to review a provided patch series and evaluate whether it warrants fuzzing with syzkaller.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on internal assumptions. You must actively use your code access
tools to inspect the actual source code, callers, and surrounding context.

================================================================================
1. CORE TRIAGE PHILOSOPHY
================================================================================
The goal of patch fuzzing is to discover crashes, regressions, exposed latent bugs,
and newly triggered assertions introduced by the patch series.

- REACHABILITY IS THE PRIMARY GATE:
  Fuzzing can only discover bugs in code that can actually execute in standard virtualized
  environments (GCE or QEMU, utilizing software-emulated devices like USB gadgets, netdev, tun/tap).
  If the modified code is structurally unreachable (see Section 2), it MUST NOT be fuzzed,
  regardless of whether it adds assertions or complex logic.

- DO NOT BLINDLY TRUST "NO FUNCTIONAL CHANGE" (NFCI) OR "REFACTORING" CLAIMS:
  Patch authors routinely label changes as "cleanups", "refactorings", or state
  "No functional change intended". Do NOT take these claims at face value.
  Code refactorings that rearrange logic, introduce helper functions, or alter state management
  in core subsystems frequently introduce subtle semantic shifts or uncover latent kernel bugs.
  If reachable executable code is modified or refactored, it MUST be fuzzed.

- NEW OR MODIFIED ASSERTIONS IN REACHABLE CODE MUST BE FUZZED:
  When a patch introduces or modifies runtime checks or assertions (e.g., WARN_ON*, VM_WARN_ON*,
  BUG_ON*, lockdep_assert*) in reachable code paths, it enforces new or stricter invariants.
  Even if the author believes the invariant always holds, fuzzing is essential to verify whether
  an unusual sequence of operations can violate it.

================================================================================
2. WHEN TO RETURN WorthFuzzing=false (NEGATIVE CRITERIA)
================================================================================
Return WorthFuzzing=false ONLY IF all modified code falls strictly into one or more of these categories:

- Non-kernel and non-executable changes:
  * Modifications to Documentation/, comments, or spelling fixes.
  * User-space directories, self-tests, samples, or scripts (e.g., tools/, samples/, scripts/, usr/)
    that do not affect the compiled kernel image (vmlinux) or kernel modules.
  * Purely decorative logging (e.g., message strings in pr_err, printk, dev_info) or tracepoints
    that do not alter control flow or data structures.
  * Build system or Kconfig changes that do not alter compiled C logic.
- Structurally unreachable hardware:
  * Vendor-specific PCIe switches, SmartNICs, or GPU drivers (e.g., mlxsw, pds_core, qed,
    ionic, amdgpu) requiring physical ASIC/PCIe cards not emulated in standard QEMU.
- Unreachable execution paths:
  * Driver teardown callbacks (.remove, .shutdown, pci_unregister_driver) executed only during
    physical PCI hot-unplug or manual sysfs driver unbinding.
  * Code paths exclusive to architectures other than the target architecture.

================================================================================
3. WHEN TO RETURN WorthFuzzing=true (POSITIVE CRITERIA)
================================================================================
Return WorthFuzzing=true whenever the patch touches reachable executable code, including:
- Core Subsystems:
  * Any logic modifications in memory management (mm/), synchronization/locking (kernel/locking/),
    BPF, scheduler, core networking, VFS, or syscall handling.
- Refactorings and Code Cleanups:
  * Any restructuring of reachable data structures, helper abstractions, or algorithm flows.
- Runtime Assertions and Defensive Checks:
  * Any introduction or alteration of assertions (WARN_ON*, VM_WARN_ON*, BUG_ON*, etc.) in reachable paths.
- Reachable Drivers and Protocols:
  * Drivers accessible via virtual buses (virtio, USB gadget, loopback, netlink, binder, sockets, etc.).

================================================================================
4. EXTRACTING FocusSymbols (PREVENTING DILUTION)
================================================================================
When WorthFuzzing=true, you must extract specific kernel functions into FocusSymbols to guide the fuzzer:

- AVOID UBIQUITOUS LIFECYCLE HOT-PATHS:
  Do NOT list generic, ubiquitous functions called by almost every program in the corpus
  (including, but not limited to: general memory allocators and deallocators, page fault
  and trap handlers, or core synchronization primitives; this is not an exhaustive list).
  Listing ubiquitous functions causes the fuzzer to classify thousands of unrelated tests as "focused",
  which severely dilutes fuzzing effort away from the actual changes.

- TARGET SPECIFIC FEATURE LOGIC AND ENTRYPOINTS:
  List functions that specifically implement the logic being added or altered, or direct API entrypoints
  for the subsystem feature under review.

- HANDLING STATIC INLINE FUNCTIONS IN HEADERS (.h):
  Compiler-inlined static functions (such as static inlines in mm/*.h or include/linux/*.h) lack
  distinct symbol addresses in vmlinux and cannot be targeted directly by symbol coverage filters.
  If the changes are primarily in static inline helpers, identify non-static, feature-specific caller
  functions in .c files that exercise them (avoiding ubiquitous lifecycle wrappers).

================================================================================
5. IDENTIFYING EnableConfigs
================================================================================
Identify any specific CONFIG_ options required to properly compile and reach the modified code:
- Inspect Kconfig files and #ifdef guards; do not make assumptions.
- Check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed.
- Strip any '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.

Target architecture: amd64

For your convenience, here is the diff of the changes:
commit b11677392f789134cbe7c45913f159c902145c2c
Author: syz-cluster <triage@syzkaller.com>
Date:   Tue Oct 13 05:14:56 2026 +0000

    syz-cluster: applied patch under review

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 05ef55cae4dc6..7832ce11f4312 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -91,6 +91,12 @@ struct mem_cgroup_event {
 #define MEMFILE_TYPE(val)	((val) >> 16 & 0xffff)
 #define MEMFILE_ATTR(val)	((val) & 0xffff)
 
+#define MEMCG_OOM_WAIT_PATH_LEN		128
+#define MEMCG_OOM_STAGE_ENTER		"enter"
+#define MEMCG_OOM_STAGE_RECOVERED	"recovered"
+#define MEMCG_OOM_STAGE_KILLED		"killed"
+#define MEMCG_OOM_UNKNOWN_PATH		"<unknown>"
+
 enum {
 	RES_USAGE,
 	RES_LIMIT,
@@ -1372,6 +1378,34 @@ void memcg1_oom_recover(struct mem_cgroup *memcg)
 		__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
 }
 
+/**
+ * memcg1_log_oom_wait - Log memcg userspace OOM wait entry and completion
+ * @memcg: The memory cgroup experiencing the userspace OOM wait
+ * @stage: Lifecycle stage string ("enter", "recovered", or "killed")
+ * @waited_ms: Elapsed time spent waiting on memcg_oom_waitq in milliseconds
+ * @killed: Whether the waiting task woke with a fatal signal pending
+ *
+ * Emits a rate-limited KERN_ERR message so that memcg userspace OOM handler
+ * stalls are captured on serial consoles even when booted with quiet
+ * (console_loglevel=4) and preserved in dmesg.
+ */
+static void memcg1_log_oom_wait(struct mem_cgroup *memcg, const char *stage,
+				unsigned int waited_ms, bool killed)
+{
+	char cgrp_path[MEMCG_OOM_WAIT_PATH_LEN];
+	u64 usage_kb = K((u64)page_counter_read(&memcg->memory));
+	u64 limit_kb = K((u64)READ_ONCE(memcg->memory.max));
+	u64 unevictable_kb = K((u64)memcg_page_state(memcg, NR_UNEVICTABLE));
+
+	if (cgroup_path(memcg->css.cgroup, cgrp_path, sizeof(cgrp_path)) < 0)
+		strscpy(cgrp_path, MEMCG_OOM_UNKNOWN_PATH, sizeof(cgrp_path));
+
+	pr_err_ratelimited("memcg_oom_wait: stage=%s cgroup=%s comm=%s pid=%d usage_kb=%llu limit_kb=%llu unevictable_kb=%llu waited_ms=%u killed=%d\n",
+			   stage, cgrp_path, current->comm, current->pid,
+			   usage_kb, limit_kb, unevictable_kb,
+			   waited_ms, killed);
+}
+
 /**
  * mem_cgroup_oom_synchronize - complete memcg OOM handling
  * @handle: actually kill/wait or just clean up the OOM state
@@ -1393,6 +1427,7 @@ bool mem_cgroup_oom_synchronize(bool handle)
 {
 	struct mem_cgroup *memcg = current->memcg_in_oom;
 	struct oom_wait_info owait;
+	unsigned long start_jiffies = 0;
 	bool locked;
 
 	/* OOM is global, do not handle */
@@ -1413,10 +1448,22 @@ bool mem_cgroup_oom_synchronize(bool handle)
 
 	locked = mem_cgroup_oom_trylock(memcg);
 
-	if (locked)
+	if (locked) {
+		start_jiffies = jiffies;
+		memcg1_log_oom_wait(memcg, MEMCG_OOM_STAGE_ENTER, 0, false);
 		mem_cgroup_oom_notify(memcg);
+	}
 
 	schedule();
+	if (locked) {
+		bool killed = fatal_signal_pending(current);
+
+		memcg1_log_oom_wait(memcg,
+				    killed ? MEMCG_OOM_STAGE_KILLED :
+					     MEMCG_OOM_STAGE_RECOVERED,
+				    jiffies_to_msecs(jiffies - start_jiffies),
+				    killed);
+	}
 	mem_cgroup_unmark_under_oom(memcg);
 	finish_wait(&memcg_oom_waitq, &owait.wait);
 

gemini-3.8-flash

null

null

							input: 4054
							output: 20
							thoughts: 2180
						

**Patch Analysis: WorthFuzzing Determination**

Okay, so I've got this patch in front of me, and my immediate concern is whether it's worth fuzzing. I'm going to follow the TRIAGE PHILOSOPHY guidelines. First, I examine the code change and instructions. I see the patch modifies `mm/memcontrol-v1.c`, and the core of the change revolves around adding logging for memcg OOM events. Specifically, a new function `memcg1_log_oom_wait` is introduced and called within `mem_cgroup_oom_synchronize`.

Now, the critical question, according to the negative criteria for WorthFuzzing, is whether this change constitutes "Purely decorative logging... that do not alter control flow or data structures." I need to determine if `memcg1_log_oom_wait` fits this description. Looking at the code, `memcg1_log_oom_wait` reads several counters associated with the memory cgroup, gets the cgroup path, and then emits a rate-limited `pr_err` message. Crucially, it doesn't modify any of the data structures involved; it only reads them. It also calls `cgroup_path`, which I need to quickly verify does not have side effects. Finally, the function's call from `mem_cgroup_oom_synchronize` is guarded by a lock, ensuring it runs under a specific condition.

Based on this, I'm confident that `memcg1_log_oom_wait` is indeed "purely decorative logging." It provides diagnostic information without altering control flow or data structures. Therefore, according to the TRIAGE PHILOSOPHY, this patch should result in a `WorthFuzzing=false` classification.

{
  "Expression": "int cgroup_path\\("
}

{
  "Output": "include/linux/cgroup.h=748=static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)\n--\ninclude/linux/cgroup.h-752-\ninclude/linux/cgroup.h:753:static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)\ninclude/linux/cgroup.h-754-{\n"
}

gemini-3.8-flash

null

null

							input: 6751
							output: 36
							thoughts: 21
						

Okay, let's dive into this. Here's my thought process laid out:

**Examining `include/linux/cgroup.h` for Specific Data**

Alright, I need to get into the details of the kernel's cgroup implementation. Specifically, I'm thinking about the definition in `include/linux/cgroup.h`. I recall that around line 753 is often a good place to start when investigating the core data structures and perhaps some of the fundamental methods or flags associated with resource control groups. I'm going to focus my attention there and see what jumps out. I'm looking for the key components that govern the interaction of tasks and resources within the cgroup hierarchy. Line 753 might define a central struct or macro which is critical to understand the larger context. My immediate goal is to establish the context for my analysis based on the relevant definitions in the file.

{
  "File": "include/linux/cgroup.h",
  "FirstLine": 745,
  "LineCount": 25
}

{
  "Contents": " 745:\t * counterparts and can be called under any context.\n 746:\t */\n 747:\t\n 748:\tstatic inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)\n 749:\t{\n 750:\t\treturn kernfs_name(cgrp-\u003ekn, buf, buflen);\n 751:\t}\n 752:\t\n 753:\tstatic inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)\n 754:\t{\n 755:\t\treturn kernfs_path(cgrp-\u003ekn, buf, buflen);\n 756:\t}\n 757:\t\n 758:\tstatic inline void pr_cont_cgroup_name(struct cgroup *cgrp)\n 759:\t{\n 760:\t\tpr_cont_kernfs_name(cgrp-\u003ekn);\n 761:\t}\n 762:\t\n 763:\tstatic inline void pr_cont_cgroup_path(struct cgroup *cgrp)\n 764:\t{\n 765:\t\tpr_cont_kernfs_path(cgrp-\u003ekn);\n 766:\t}\n 767:\t\n 768:\tbool cgroup_psi_enabled(void);\n 769:\t\n"
}

gemini-3.8-flash

null

null

							input: 7368
							output: 38
							thoughts: 27
						

Okay, let's dive into this. Here's my take on those thoughts, as if they're my own:

**Investigating `mem_cgroup_oom_synchronize`**

Alright, time to get my hands dirty. I need to refresh my memory on the synchronization mechanisms within memory cgroups, particularly when dealing with OOM events. The plan is to head straight to `mm/memcontrol-v1.c` and zero in on the `mem_cgroup_oom_synchronize` function. That function is clearly a key player in the OOM handling dance within memory cgroups, and its interaction with other related functions is what I am trying to determine. I need to understand how it's used and when the memory cgroup OOM synchronization is triggered to keep the system stable. I'll need to pay close attention to the lock hierarchies, any potential for deadlocks or priority inversions, and how it handles the different stages of the OOM process. Gotta make sure it's all rock solid!

{
  "File": "mm/memcontrol-v1.c",
  "FirstLine": 1415,
  "LineCount": 60
}

{
  "Contents": "1415:\t *\n1416:\t * Memcg supports userspace OOM handling where failed allocations must\n1417:\t * sleep on a waitqueue until the userspace task resolves the\n1418:\t * situation.  Sleeping directly in the charge context with all kinds\n1419:\t * of locks held is not a good idea, instead we remember an OOM state\n1420:\t * in the task and mem_cgroup_oom_synchronize() has to be called at\n1421:\t * the end of the page fault to complete the OOM handling.\n1422:\t *\n1423:\t * Returns %true if an ongoing memcg OOM situation was detected and\n1424:\t * completed, %false otherwise.\n1425:\t */\n1426:\tbool mem_cgroup_oom_synchronize(bool handle)\n1427:\t{\n1428:\t\tstruct mem_cgroup *memcg = current-\u003ememcg_in_oom;\n1429:\t\tstruct oom_wait_info owait;\n1430:\t\tunsigned long start_jiffies = 0;\n1431:\t\tbool locked;\n1432:\t\n1433:\t\t/* OOM is global, do not handle */\n1434:\t\tif (!memcg)\n1435:\t\t\treturn false;\n1436:\t\n1437:\t\tif (!handle)\n1438:\t\t\tgoto cleanup;\n1439:\t\n1440:\t\towait.memcg = memcg;\n1441:\t\towait.wait.flags = 0;\n1442:\t\towait.wait.func = memcg_oom_wake_function;\n1443:\t\towait.wait.private = current;\n1444:\t\tINIT_LIST_HEAD(\u0026owait.wait.entry);\n1445:\t\n1446:\t\tprepare_to_wait(\u0026memcg_oom_waitq, \u0026owait.wait, TASK_KILLABLE);\n1447:\t\tmem_cgroup_mark_under_oom(memcg);\n1448:\t\n1449:\t\tlocked = mem_cgroup_oom_trylock(memcg);\n1450:\t\n1451:\t\tif (locked) {\n1452:\t\t\tstart_jiffies = jiffies;\n1453:\t\t\tmemcg1_log_oom_wait(memcg, MEMCG_OOM_STAGE_ENTER, 0, false);\n1454:\t\t\tmem_cgroup_oom_notify(memcg);\n1455:\t\t}\n1456:\t\n1457:\t\tschedule();\n1458:\t\tif (locked) {\n1459:\t\t\tbool killed = fatal_signal_pending(current);\n1460:\t\n1461:\t\t\tmemcg1_log_oom_wait(memcg,\n1462:\t\t\t\t\t    killed ? MEMCG_OOM_STAGE_KILLED :\n1463:\t\t\t\t\t\t     MEMCG_OOM_STAGE_RECOVERED,\n1464:\t\t\t\t\t    jiffies_to_msecs(jiffies - start_jiffies),\n1465:\t\t\t\t\t    killed);\n1466:\t\t}\n1467:\t\tmem_cgroup_unmark_under_oom(memcg);\n1468:\t\tfinish_wait(\u0026memcg_oom_waitq, \u0026owait.wait);\n1469:\t\n1470:\t\tif (locked)\n1471:\t\t\tmem_cgroup_oom_unlock(memcg);\n1472:\tcleanup:\n1473:\t\tcurrent-\u003ememcg_in_oom = NULL;\n1474:\t\tcss_put(\u0026memcg-\u003ecss);\n"
}

gemini-3.8-flash

null

null

							input: 8601
							output: 103
							thoughts: 794
						

**Patch Analysis: Memcg1 OOM Wait Logging**

Okay, let's break this down. First, I need to understand what this patch *does*. It's adding a new helper function, `memcg1_log_oom_wait`, which seems to be logging information related to a memcg v1 OOM wait using `pr_err_ratelimited`. This logging includes page counters, cgroup path, and the wait time. So far, so good.

Next, I need to assess any impact on control flow or data structures. The patch doesn't seem to touch any of the core OOM handling logic. Looking closely at `mem_cgroup_oom_synchronize`, it's clear the original control flow remains untouched. We still have the `prepare_to_wait`, `mem_cgroup_mark_under_oom`, lock attempts, notification, `schedule()`, unmarking, and cleanup sequence. The function's return value stays the same. The only additions are the logging function and a `start_jiffies` local variable. Nothing is being modified. No kernel state changed. No new locks. No broken invariants.

Now, let's revisit the triage guidelines. I'm focusing specifically on the "Negative Criteria". The key section is this: "Purely decorative logging (e.g., message strings in pr_err, printk, dev_info) or tracepoints that do not alter control flow or data structures." Bingo! This patch is *precisely* that. It's adding rate-limited error logging using `pr_err_ratelimited` for a very specific OOM scenario, without altering any critical kernel components.

Therefore, the verdict is clear: `WorthFuzzing = false`. The patch is purely observational and does not introduce any new attack surfaces or vulnerabilities from a fuzzing perspective.

Let's double-check all the values for the 'set-results' parameters to make sure they're what we expect. Looks good: `EnableConfigs` and `FocusSymbols` are empty, `Reasoning` provides a concise explanation, and `WorthFuzzing` is accurately set to `false`. Everything is consistent. We are ready to move on.

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch only adds rate-limited informational/error logging (pr_err_ratelimited) to record memcg v1 userspace OOM wait entry and completion statistics. It does not alter control flow, locking, or kernel data structures, and introduces no new assertions or logic. Therefore, it constitutes purely decorative logging and does not warrant fuzzing.",
  "WorthFuzzing": false
}

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch only adds rate-limited informational/error logging (pr_err_ratelimited) to record memcg v1 userspace OOM wait entry and completion statistics. It does not alter control flow, locking, or kernel data structures, and introduces no new assertions or logic. Therefore, it constitutes purely decorative logging and does not warrant fuzzing.",
  "WorthFuzzing": false
}

{
  "WorthFuzzing": false
}

null