CVE-2025-38564: In the Linux kernel, the following vulnerability has been resolved: perf/core: Handle buffer mapping fail correctly in perf_mmap() After successful ...

Description

In the Linux kernel, the following vulnerability has been resolved: perf/core: Handle buffer mapping fail correctly in perf_mmap() After successful allocation of a buffer or a successful attachment to an existing buffer perf_mmap() tries to map the buffer read only into the page table. If that fails, the already set up page table entries are zapped, but the other perf specific side effects of that failure are not handled. The calling code just cleans up the VMA and does not invoke perf_mmap_close(). This leaks reference counts, corrupts user->vm accounting and also results in an unbalanced invocation of event::event_mapped(). Cure this by moving the event::event_mapped() invocation before the map_range() call so that on map_range() failure perf_mmap_close() can be invoked without causing an unbalanced event::event_unmapped() call. perf_mmap_close() undoes the reference counts and eventually frees buffers.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.14%

4.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 6.14, < 6.15.10
Linux	Linux Kernel	>= 6.16, < 6.16.1

References

Timeline

Published: Aug 19, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-38564?

In the Linux kernel, the following vulnerability has been resolved: perf/core: Handle buffer mapping fail correctly in perf_mmap() After successful allocation of a buffer or a successful attachment to an existing buffer perf_mmap() tries to map the buffer read only into the page table. If that fails, the already set up page table entries are zapped, but the other perf specific side effects of that failure are not handled. The calling code just cleans up the VMA and does not invoke perf_mmap_close(). This leaks reference counts, corrupts user->vm accounting and also results in an unbalanced invocation of event::event_mapped(). Cure this by moving the event::event_mapped() invocation before the map_range() call so that on map_range() failure perf_mmap_close() can be invoked without causing an unbalanced event::event_unmapped() call. perf_mmap_close() undoes the reference counts and eventually frees buffers.

How severe is CVE-2025-38564?

CVE-2025-38564 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.14% probability of exploitation in the next 30 days.

How do I fix CVE-2025-38564?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.