SB2026080766 - Race condition in Linux kernel fuse

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-64588)

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

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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 fuse io_uring readiness handling in fs/fuse/dev_uring.c and fs/fuse/dev_uring_i.h when processing concurrent ring readiness checks and request dispatch. A local user can trigger concurrent operations to cause a denial of service.

The issue occurs on weakly-ordered architectures and can lead to requests being dispatched through a stale fiq->ops pointer.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/46725a0056c884cf58a6897f222892807327d82d
• https://git.kernel.org/stable/c/b156bb9966972122b148acab8bdf415cdb8176a3
• https://git.kernel.org/stable/c/d01a09b442cb786cd44ccc7c84d57e2856d6737c