SB20261022282 - Incomplete cleanup in Linux kernel smb client

Description

This security bulletin contains information about 1 vulnerability.

1) Incomplete cleanup (CVE-ID: CVE-2026-98685)

CWE-ID: CWE-459 - Incomplete cleanup

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

The vulnerability allows a local user to corrupt file content by making stale page-cache data visible after a file is extended.

The vulnerability exists due to incomplete page-cache invalidation in the Linux kernel SMB client's cifs_remap_file_range() function when a clone-range operation extends a file beyond its previous end. A local user can dirty data past the end of a file through a memory mapping and extend the file through a clone-range operation to expose that data as file content because the cached folio straddling the previous end is not discarded.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/15bb9f1d3e967e328649e92a1451e60a0dc66118
• https://git.kernel.org/stable/c/4721587f96cb8de8164f3fd203093a0875560999