# CVE-2025-40359: perf/x86/intel: Fix KASAN global-out-of-bounds warning

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-12-16 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.11

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/1b61a1da3d8105ea1be548c94c2856697eb7ffd1
- https://git.kernel.org/stable/c/710a72e81a7028e1ad1a10eb14f941f8dd45ffd3
- https://git.kernel.org/stable/c/0ba6502ce167fc3d598c08c2cc3b4ed7ca5aa251

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Page: https://cve.now/CVE-2025-40359
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