Cloudanix VulnDB

CVE-2025-68798

None

CVSS

—

EPSS

0.2%

Published

Jan 13, 2026

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A bug in Linux on AMD computers can cause the system to crash when performance monitoring tools run under certain timing conditions.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Race Condition
Remediation
Patch
Effort
Low
Patch risk
Low

What it actually does

A NULL pointer dereference in amd_pmu_enable_all() caused by a race condition where cpuc->events[idx] becomes NULL during NMI throttling on AMD CPUs, leading to a general protection fault when enabling perf events.

Why it matters to the business

Can cause kernel crashes or system instability on AMD Linux systems under perf monitoring workloads, potentially leading to denial of service. Low exploitation likelihood based on EPSS with no known threat actors or ransomware use.

How an attack unfolds

An attacker uses a fuzzer like Syzkaller to set up perf events and triggers scheduling operations concurrent with NMI-based throttling via x86_pmu_stop, causing the event pointer to be NULL when amd_pmu_enable_all attempts to access it on AMD hardware.

How to fix it

Update the Linux kernel to include commit 49324a0c40f7e9bae1bd0362d23fc42232e14621 or later.

How to confirm the fix worked

Verify the presence of commit 49324a0c40f7e9bae1bd0362d23fc42232e14621 in the kernel source tree or confirm updated kernel packages from distribution vendors.

Typical attack path

  1. Create and schedule perf events on AMD system
  2. Trigger NMI throttle path that clears events[idx]
  3. Race window allows amd_pmu_enable_all to run with NULL event
  4. Dereference triggers GPF in x86_pmu_enable_event

How to detect it

Inspect kernel logs for general protection faults, NMI handler timeouts, or stack traces referencing amd_pmu_enable_all, x86_pmu_enable_event, or perf_event_nmi_handler.

  • amd_pmu_enable_all
  • general protection fault, probably for non-canonical address
  • perf_event_nmi_handler took too long to run
  • x86_pmu_enable_event

What your security team should do

  • Apply the kernel fix on all AMD systems running affected versions
  • Restrict unprivileged perf_event access until patched
  • Monitor kernel logs for related GPFs or NMI warnings

The record

In the Linux kernel, the following vulnerability has been resolved: perf/x86/amd: Check event before enable to avoid GPF On AMD machines cpuc->events[idx] can become NULL in a subtle race condition with NMI->throttle->x86_pmu_stop(). Check event for NULL in amd_pmu_enable_all() before enable to avoid a GPF. This appears to be an AMD only issue. Syzkaller reported a GPF in amd_pmu_enable_all. INFO: NMI handler (perf_event_nmi_handler) took too long to run: 13.143 msecs Oops: general protection fault, probably for non-canonical address 0xdffffc0000000034: 0000 PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x00000000000001a0-0x00000000000001a7] CPU: 0 UID: 0 PID: 328415 Comm: repro_36674776 Not tainted 6.12.0-rc1-syzk RIP: 0010:x86_pmu_enable_event (arch/x86/events/perf_event.h:1195 arch/x86/events/core.c:1430) RSP: 0018:ffff888118009d60 EFLAGS: 00010012 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000034 RSI: 0000000000000000 RDI: 00000000000001a0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002 R13: ffff88811802a440 R14: ffff88811802a240 R15: ffff8881132d8601 FS: 00007f097dfaa700(0000) GS:ffff888118000000(0000) GS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200001c0 CR3: 0000000103d56000 CR4: 00000000000006f0 Call Trace: <IRQ> amd_pmu_enable_all (arch/x86/events/amd/core.c:760 (discriminator 2)) x86_pmu_enable (arch/x86/events/core.c:1360) event_sched_out (kernel/events/core.c:1191 kernel/events/core.c:1186 kernel/events/core.c:2346) __perf_remove_from_context (kernel/events/core.c:2435) event_function (kernel/events/core.c:259) remote_function (kernel/events/core.c:92 (discriminator 1) kernel/events/core.c:72 (discriminator 1)) __flush_smp_call_function_queue (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/csd.h:64 kernel/smp.c:135 kernel/smp.c:540) __sysvec_call_function_single (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./arch/x86/include/asm/trace/irq_vectors.h:99 arch/x86/kernel/smp.c:272) sysvec_call_function_single (arch/x86/kernel/smp.c:266 (discriminator 47) arch/x86/kernel/smp.c:266 (discriminator 47)) </IRQ>

Affected packages

Ecosystem Package Introduced Fixed
Linux Kernel 5.19.0 6.1.160
Mageia:9 kernel 0 6.6.120-1.mga9
Mageia:9 kernel-linus 0 6.6.120-1.mga9
Mageia:9 kmod-virtualbox 0 7.1.14-14.mga9
Mageia:9 kmod-xtables-addons 0 3.24-88.mga9
openSUSE:Leap 16.0 dtb-aarch64 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-64kb 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-azure 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-default 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-default-base 0 6.12.0-160000.26.1.160000.2.7
openSUSE:Leap 16.0 kernel-docs 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-kvmsmall 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-obs-build 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-obs-qa 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-rt 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-source 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-syms 0 6.12.0-160000.26.1
openSUSE:Leap 16.0 kernel-zfcpdump 0 6.12.0-160000.26.1

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