| Seq | Timestamp | Type | Name | Duration |
|---|---|---|---|---|
| 0/0 | 2026/09/15 10:50 | flow | patch-triage |
0mArgs:null Results: {
"EnableConfigs": null,
"FocusSymbols": [],
"KMSANReasoning": "",
"NeedsKMSAN": false,
"Reasoning": "The patch consists entirely of documentation and code comment updates correcting references from VCPU_RUN/KVM_VCPU_RUN to KVM_RUN. There are no changes to executable code.",
"WorthFuzzing": false
} |
| 1/1 | 2026/09/15 10:50 | action | read-patch-diff |
0mArgs:null Results: {
"PatchDiff": "commit 8f54fcaa3e16c676915bba4d454acea087407a2c\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Tue Sep 15 10:50:25 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/Documentation/virt/kvm/arm/pkvm.rst b/Documentation/virt/kvm/arm/pkvm.rst\nindex 514992a79a833..18d8afe36ebce 100644\n--- a/Documentation/virt/kvm/arm/pkvm.rst\n+++ b/Documentation/virt/kvm/arm/pkvm.rst\n@@ -67,7 +67,7 @@ largely due to the lack of MMU notifiers:\n then it will either return ``-EFAULT`` or forcefully reclaim the\n memory pages. Reclaimed memory is zeroed by the hypervisor and a\n subsequent attempt to access it in the pVM will return ``-EFAULT``\n- from the ``VCPU_RUN`` ioctl().\n+ from the ``KVM_RUN`` ioctl().\n \n CPU state isolation\n -------------------\ndiff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c\nindex 8b080804bc90b..a18ec13bd6677 100644\n--- a/arch/arm64/kvm/arm.c\n+++ b/arch/arm64/kvm/arm.c\n@@ -1263,7 +1263,7 @@ static int noinstr kvm_arm_vcpu_enter_exit(struct kvm_vcpu *vcpu)\n * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code\n * @vcpu:\tThe VCPU pointer\n *\n- * This function is called through the VCPU_RUN ioctl called from user space. It\n+ * This function is called through the KVM_RUN ioctl called from user space. It\n * will execute VM code in a loop until the time slice for the process is used\n * or some emulation is needed from user space in which case the function will\n * return with return value 0 and with the kvm_run structure filled in with the\ndiff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c\nindex dbac3573b2c89..db090f4c5e95b 100644\n--- a/arch/powerpc/kvm/book3s_hv.c\n+++ b/arch/powerpc/kvm/book3s_hv.c\n@@ -269,7 +269,7 @@ static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)\n * stolen time for a vcore when it is inactive, or for a vcpu\n * when it is in state RUNNING or NOTREADY. NOTREADY is a bit of\n * a misnomer; it means that the vcpu task is not executing in\n- * the KVM_VCPU_RUN ioctl, i.e. it is in userspace or elsewhere in\n+ * the KVM_RUN ioctl, i.e. it is in userspace or elsewhere in\n * the kernel. We don't have any way of dividing up that time\n * between time that the vcpu is genuinely stopped, time that\n * the task is actively working on behalf of the vcpu, and time\ndiff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h\nindex 03bfc92864b6e..acae5a61e7f8f 100644\n--- a/include/linux/kvm_host.h\n+++ b/include/linux/kvm_host.h\n@@ -562,7 +562,7 @@ static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)\n \t/*\n \t * The memory barrier ensures a previous write to vcpu-\u003erequests cannot\n \t * be reordered with the read of vcpu-\u003emode. It pairs with the general\n-\t * memory barrier following the write of vcpu-\u003emode in VCPU RUN.\n+\t * memory barrier following the write of vcpu-\u003emode in KVM_RUN.\n \t */\n \tsmp_mb__before_atomic();\n \treturn cmpxchg(\u0026vcpu-\u003emode, IN_GUEST_MODE, EXITING_GUEST_MODE);\ndiff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c\nindex 65eb26a0520d8..cc391b0666a6d 100644\n--- a/virt/kvm/kvm_main.c\n+++ b/virt/kvm/kvm_main.c\n@@ -470,7 +470,7 @@ static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)\n \tkvm_dirty_ring_free(\u0026vcpu-\u003edirty_ring);\n \n \t/*\n-\t * No need for rcu_read_lock as VCPU_RUN is the only place that changes\n+\t * No need for rcu_read_lock as KVM_RUN is the only place that changes\n \t * the vcpu-\u003epid pointer, and at destruction time all file descriptors\n \t * are already gone.\n \t */\n"
} |
| 2/1 | 2026/09/15 10:50 | agent | patch-evaluator |
0mModel:core Args: null Results: {
"EnableConfigs": null,
"FocusSymbols": [],
"Reasoning": "The patch consists entirely of documentation and code comment updates correcting references from VCPU_RUN/KVM_VCPU_RUN to KVM_RUN. There are no changes to executable code.",
"WorthFuzzing": false
}Instruction: 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.
Prompt: Target architecture: amd64
For your convenience, here is the diff of the changes:
commit 8f54fcaa3e16c676915bba4d454acea087407a2c
Author: syz-cluster <triage@syzkaller.com>
Date: Tue Sep 15 10:50:25 2026 +0000
syz-cluster: applied patch under review
diff --git a/Documentation/virt/kvm/arm/pkvm.rst b/Documentation/virt/kvm/arm/pkvm.rst
index 514992a79a833..18d8afe36ebce 100644
--- a/Documentation/virt/kvm/arm/pkvm.rst
+++ b/Documentation/virt/kvm/arm/pkvm.rst
@@ -67,7 +67,7 @@ largely due to the lack of MMU notifiers:
then it will either return ``-EFAULT`` or forcefully reclaim the
memory pages. Reclaimed memory is zeroed by the hypervisor and a
subsequent attempt to access it in the pVM will return ``-EFAULT``
- from the ``VCPU_RUN`` ioctl().
+ from the ``KVM_RUN`` ioctl().
CPU state isolation
-------------------
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 8b080804bc90b..a18ec13bd6677 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1263,7 +1263,7 @@ static int noinstr kvm_arm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
* kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
* @vcpu: The VCPU pointer
*
- * This function is called through the VCPU_RUN ioctl called from user space. It
+ * This function is called through the KVM_RUN ioctl called from user space. It
* will execute VM code in a loop until the time slice for the process is used
* or some emulation is needed from user space in which case the function will
* return with return value 0 and with the kvm_run structure filled in with the
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index dbac3573b2c89..db090f4c5e95b 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -269,7 +269,7 @@ static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
* stolen time for a vcore when it is inactive, or for a vcpu
* when it is in state RUNNING or NOTREADY. NOTREADY is a bit of
* a misnomer; it means that the vcpu task is not executing in
- * the KVM_VCPU_RUN ioctl, i.e. it is in userspace or elsewhere in
+ * the KVM_RUN ioctl, i.e. it is in userspace or elsewhere in
* the kernel. We don't have any way of dividing up that time
* between time that the vcpu is genuinely stopped, time that
* the task is actively working on behalf of the vcpu, and time
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 03bfc92864b6e..acae5a61e7f8f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -562,7 +562,7 @@ static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
/*
* The memory barrier ensures a previous write to vcpu->requests cannot
* be reordered with the read of vcpu->mode. It pairs with the general
- * memory barrier following the write of vcpu->mode in VCPU RUN.
+ * memory barrier following the write of vcpu->mode in KVM_RUN.
*/
smp_mb__before_atomic();
return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 65eb26a0520d8..cc391b0666a6d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -470,7 +470,7 @@ static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
kvm_dirty_ring_free(&vcpu->dirty_ring);
/*
- * No need for rcu_read_lock as VCPU_RUN is the only place that changes
+ * No need for rcu_read_lock as KVM_RUN is the only place that changes
* the vcpu->pid pointer, and at destruction time all file descriptors
* are already gone.
*/
|
| 3/2 | 2026/09/15 10:50 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 3958 output: 70 thoughts: 589 Thoughts: **Analysis of the KVM Patch** Okay, let's break down this patch. The target is amd64, which is expected. The diff is straightforward. It looks like a pure cleanup effort, primarily focused on consistent naming conventions. Specifically, it's just a refactoring, replacing instances of "VCPU_RUN" and "KVM_VCPU_RUN" with "KVM_RUN" across documentation and comments. *Crucially*, there's *zero* modification to any actual executable C code. No functional changes, no new features – just tidying up references. Now, let's run this through our fuzzing criteria. We have the guideline in the prompt: "*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...*". And this patch *precisely* fits that description. All changes are confined to documentation and comments. No code, no functionality, nada. Therefore, `WorthFuzzing = false`. No need to expend resources here. The `FocusSymbols` and `EnableConfigs` arrays stay empty, of course. Just to be absolutely certain, I've re-checked the diff and verified that it only affects the listed files, and the modifications are *exclusively* comment/doc updates. No executable code is touched. This means `set-results`. It's a clean "no-op" in terms of our fuzzing goals. |
| 4/2 | 2026/09/15 10:50 | tool | set-results |
0mArgs:{
"EnableConfigs": [],
"FocusSymbols": [],
"Reasoning": "The patch consists entirely of documentation and code comment updates correcting references from VCPU_RUN/KVM_VCPU_RUN to KVM_RUN. There are no changes to executable code.",
"WorthFuzzing": false
}Results: {
"EnableConfigs": null,
"FocusSymbols": [],
"Reasoning": "The patch consists entirely of documentation and code comment updates correcting references from VCPU_RUN/KVM_VCPU_RUN to KVM_RUN. There are no changes to executable code.",
"WorthFuzzing": false
} |
| 5/1 | 2026/09/15 10:50 | action | If |
0mArgs:{
"WorthFuzzing": false
}Results: null |
| Total Calls | Total Tokens | Avg Tokens | Total Duration (Seconds) | Avg Duration (Seconds) |
|---|
| Total Calls | Total Duration (Seconds) | Avg Duration (Seconds) |
|---|