SB2026081661 - Race condition in Linux kernel smb client

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-72315)

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

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper synchronization in the cifs client direct i/o request cleanup and unmount handling when processing direct i/o writes during unmount. A local user can trigger direct i/o activity and unmount a cifs mount to cause a denial of service.

The issue results in a busy dentry warning because dentry reference counts may remain in use until delayed cleanup work completes.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/75f5c412fa867efa0bf9b646bffe0d912109e84a
• https://git.kernel.org/stable/c/f0eac9c3c3711f24efc2aaf12b8ec3e54a38c214