Improper locking in Linux kernel - CVE-2026-97521
Published: September 24, 2026
Vulnerability identifier: #VU151967
CSH Severity: Low
CVSS v4: 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]
CVE-ID: CVE-2026-97521
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
Linux kernel
How to mitigate CVE-2026-97521
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3