SB2026091943 - Race condition in Linux kernel smb server

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-90167)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause incorrect oplock state handling.

The vulnerability exists due to a race condition in ksmbd oplock handling when handling concurrent SMB requests that close files and break oplocks. A remote attacker can trigger concurrent oplock close and break operations to cause incorrect oplock state handling.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/5f97bac88bfb333f426f01c118b8235e75af8d96
• https://git.kernel.org/stable/c/b0148dc5625dbfd50596ac63c7487c12e8a8ab03