SB2026092481 - Improper locking in Linux kernel gfs2

Description

This security bulletin contains information about 1 vulnerability.

1) Improper locking (CVE-ID: CVE-2026-97521)

CWE-ID: CWE-667 - Improper Locking

CVSSv4: 0 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to trigger a sleeping-function warning from an invalid context.

The vulnerability exists due to improper locking in gfs2_quota_init() when checking duplicate quota_change IDs while holding qd_lock and the quota hash bucket bitlock. A local user can cause duplicate quota_change IDs to be processed during quota initialization to trigger a sleeping-function warning from an invalid context.

The issue occurs on PREEMPT_RT systems because lockref_get_not_dead() may sleep.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/7fdcf16e5e14e11028f5bcaa6d25075eb5e876a0
• https://git.kernel.org/stable/c/812a766e2b0a8f4d094393fad13475c57f5f86db
• https://git.kernel.org/stable/c/b99a1f0f18ee50445907f55069e88bcfd8947383