SB20260812360 - Race condition in Linux kernel block driver

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-68173)

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 the ublk driver recovery and device readiness handling in drivers/block/ublk_drv.c when processing user recovery state transitions. A local user can trigger recovery completion in an invalid state to cause a denial of service.

The issue can strand a request while holding its tag, causing subsequent fsync operations to block in uninterruptible sleep and device teardown to hang.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/432a9b2780c0a01caf547bd1fc2fcf28aeb8d173
• https://git.kernel.org/stable/c/7dd26adf7e7d482af524e3a0cca4a81ef7c159d0
• https://git.kernel.org/stable/c/8f188dd11a1c2ad94caeaee36ef68bb8221d4a12