SB20260812341 - Use-after-free in Linux kernel core

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-68201)

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 use-after-free in the ALSA timer subsystem, specifically slave timer callback handling in snd_timer_close_locked() and remove_slave_links(), when closing a master timer instance while a slave callback is still in flight. A local user can trigger timer close operations while a slave callback is active to cause a denial of service.

The issue occurs because a slave instance can be freed after its ->timer pointer is cleared, causing its close path to skip draining an already running callback.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/2b298997786876b225cff2446e11a0fa6f602f6d
• https://git.kernel.org/stable/c/426c0ff1c433d6030610ad4f9375746dfe931caa
• https://git.kernel.org/stable/c/bdefe1346a8e6b8dc8593406dc2617e985fcbcab
• https://git.kernel.org/stable/c/cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0