SB2026081593 - Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel liveupdate

Description

This security bulletin contains information about 1 vulnerability.

1) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2026-74370)

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

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 time-of-check time-of-use race condition in luo_session_retrieve() when retrieving a liveupdate session. A local user can trigger concurrent session operations to cause a denial of service.

The issue arises when a concurrent thread releases and frees the session between session lookup and acquisition of the session mutex.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/d3ae9e7fddb4036f50003d7fa1ef52801fdb961b
• https://git.kernel.org/stable/c/d944170607b872a1f93713c555ad3f0efde3a9b8