SB20260928112 - Race condition in Linux kernel btrfs

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-98079)

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: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 a race condition in the Btrfs zstd workspace management code when waiting for a zstd workspace after workspace allocation fails. A local user can trigger the lost-wakeup condition to cause a denial of service.

The condition involves maximum-level workspaces, for which a fallback workspace is retained for waiters.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0de9f31d447ae71ab08c7850a321682f8d2907c3
• https://git.kernel.org/stable/c/2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7
• https://git.kernel.org/stable/c/d8f57049521948df5f50797141472fbbed3b0723