SB20261022279 - Race condition in Linux kernel smb client

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-98683)

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

CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/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 contents by causing stale data to reappear in a range that was zeroed.

The vulnerability exists due to improper synchronization of dirty data writeback in the Linux kernel SMB client's smb3_zero_range() function when zeroing an interior file range that does not reach the end of the file. A local user can trigger zero-range operations on a file with overlapping dirty cached data, allowing subsequent writeback to overwrite the zeroed range on the server with stale data.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/8f8d32c1044f70e46e87550e039a15ff20a4b21c
• https://git.kernel.org/stable/c/cecf4114069fc19629d284710fd783d56bbca862
• https://git.kernel.org/stable/c/e8ba21c7e6ef3d4cb617858760673877b2e4a2bb