Improper locking in Linux kernel - CVE-2026-89491
Published: September 12, 2026
Vulnerability identifier: #VU149324
CSH Severity: Low
CVSS v4: 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]
CVE-ID: CVE-2026-89491
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper locking in o2hb_region_pin() when calling o2nm_depend_item() while holding o2hb_live_lock. A local user can trigger heartbeat region pinning to cause a denial of service.
The issue manifests as a sleeping-in-atomic-context BUG under CONFIG_DEBUG_ATOMIC_SLEEP.
Affected software
Linux kernel
How to mitigate CVE-2026-89491
Install security update from vendor's repository.