SB20260824195 - Use-after-free in Linux kernel events

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-74637)

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 denial of service.

The vulnerability exists due to a use-after-free in perf/core group handling when processing a PERF_IOC_FLAG_GROUP ioctl on a detached sibling event after CPU hotplug detachment. A local user can issue a crafted ioctl on a surviving perf event file descriptor to cause a denial of service.

The issue occurs when a sibling event is detached with DETACH_GROUP and kept alive while its group_leader pointer still references a leader that is later freed.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1e7abfeb23c12bf46f6457e4a3e1a1a300d50619
• https://git.kernel.org/stable/c/42c5ca1f0a288a52878bd72a5595b08261057438
• https://git.kernel.org/stable/c/a979a642402d0b1f856c7a729b4cb2d92de4cf2f
• https://git.kernel.org/stable/c/b42948f9e0d1ea4dbd5742ce1dfc7688de5d4a35