CVE-2025-40359 perf/x86/intel: Fix KASAN global-out-of-bounds warning
A local attacker can trigger a kernel out-of-bounds read in the Intel perf subsystem, potentially causing a system crash or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40359?
CVE-2025-40359 is a memory corruption vulnerability in Linux, published on 16 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix KASAN global-out-of-bounds warning
When running "perf mem record" command on CWF, the below KASAN global-out-of-bounds warning is seen.
================================================================== BUG: KASAN: global-out-of-bounds in cmt_latency_data+0x176/0x1b0 Read of size 4 at addr ffffffffb721d000 by task dtlb/9850
Call Trace:
kasan_report+0xb8/0xf0 cmt_latency_data+0x176/0x1b0 setup_arch_pebs_sample_data+0xf49/0x2560 intel_pmu_drain_arch_pebs+0x577/0xb00 handle_pmi_common+0x6c4/0xc80
The issue is caused by below code in __grt_latency_data(). The code tries to access x86_hybrid_pmu structure which doesn't exist on non-hybrid platform like CWF.
WARN_ON_ONCE(hybrid_pmu(event->pmu)->pmu_type == hybrid_big)
So add is_hybrid() check before calling this WARN_ON_ONCE to fix the global-out-of-bounds access issue.
Which versions are affected by CVE-2025-40359?
How do I fix CVE-2025-40359?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-40359 being exploited?
There is no known exploitation of CVE-2025-40359 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40359, DEBIAN-CVE-2025-40359, GHSA-4mfx-236h-48h4, UBUNTU-CVE-2025-40359.