SB20260727284 - Use-after-free in Linux kernel events

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-64300)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a use-after-free condition.

The vulnerability exists due to a use-after-free in map_range() in the perf subsystem when mapping auxiliary buffer pages shared between events. A local user can trigger a race between buffer allocation and page mapping to cause a use-after-free condition.

The issue arises when multiple events share one ring buffer via PERF_EVENT_IOC_SET_OUTPUT, and pages mapped as VM_PFNMAP lack refcount protection.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0cff05bd2186020f8706233e261016d149cc24db
• https://git.kernel.org/stable/c/5948aaf64f81f217a25dcc2bf6c0779bca19566c
• https://git.kernel.org/stable/c/c8b7e113f7b61eef2f017e6329c27c2331058c5a