SB2026082790 - Race condition in Linux kernel s390 cio driver

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-80547)

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

CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to disclose sensitive information, modify data, or cause a denial of service.

The vulnerability exists due to a race condition in the vfio_ccw crw handling logic when processing asynchronous hardware events and userspace reads of the crw region. A local user can trigger concurrent access to the crw list to disclose sensitive information, modify data, or cause a denial of service.

The issue affects the s390 vfio_ccw subsystem and involves the crw queue being accessed from asynchronous hardware-driven paths.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/16b0798024c0e9117e395829ddbbe70981c79d9c
• https://git.kernel.org/stable/c/49fa26b0df009dc1f420980bd71780e70615b83b
• https://git.kernel.org/stable/c/7902be374cbfc11c3435e1e87bf22195bf06a558
• https://git.kernel.org/stable/c/c76c4ee72bfc3824f4f491f18ed0323bf2e2daf9