SB2026091953 - Use-after-free in Linux kernel smb server

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-90162)

CWE-ID: CWE-416 - Use After Free

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

The vulnerability allows a remote attacker to cause a use-after-free and double-free.

The vulnerability exists due to improper synchronization in smb2_lock() when processing SMB2_LOCK request arrays. A remote attacker can submit a crafted SMB2_LOCK request with a later failing lock element while concurrently sending an UNLOCK request to cause a use-after-free and double-free.

The concurrent UNLOCK request must target the same connection before rollback processing occurs.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/29f74f0f2e6df3b393b7b66e810136d0c64e3c59
• https://git.kernel.org/stable/c/a1d26dfb32919088e3638dca01068df3c4507433