CVE-2025-38565
HighCVSS 7.8Summary
In the Linux kernel, a vulnerability was resolved in perf/core: when `perf_mmap()` fails to allocate a buffer, it still invokes the `event_mapped()` callback, which on X86 may increment the `perf_rdpmc_allowed` reference counter. Since `perf_mmap_close()` is never called in this case, the counter is not decremented, causing a reference count leak. The fix returns early on failure.
Risk Assessment
A local user can repeatedly trigger failed perf mappings, causing a reference counter leak and potentially destabilizing the system or exhausting resources. This requires access to the perf interface.
Recommendation
Update the Linux kernel to a version containing the fix. Restrict access to the perf_event interface for unprivileged users.
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Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: perf/core: Exit early on perf_mmap() fail When perf_mmap() fails to allocate a buffer, it still invokes the event_mapped() callback of the related event. On X86 this might increase the perf_rdpmc_allowed reference counter. But nothing undoes this as perf_mmap_close() is never called in this case, which causes another reference count leak. Return early on failure to prevent that.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS