SB20260912295 - NULL pointer dereference in Linux kernel lockd

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-89484)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/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 NULL pointer dereference in nlmclnt_locks_release_private() when releasing a partially initialized file_lock after lockowner allocation failure. A local user can trigger a lockowner allocation failure during NLM file lock initialization to cause a denial of service.

The VFS may release the partially initialized file lock after NLM client processing returns an out-of-memory error.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/07adfbb3de7529f58ca708a97ead7fa4fdb71056
• https://git.kernel.org/stable/c/4c7fc129db061c7daab841c4f3c342d894832362
• https://git.kernel.org/stable/c/51af080ca4e553256c59a75a877b9b4fff828311
• https://git.kernel.org/stable/c/d662f7fc04fde305a27f304b3cd19b614d366839