Improper locking in Linux kernel - CVE-2026-53123
Published: June 25, 2026
Vulnerability identifier: #VU135187
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-53123
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper synchronization in the raid456 reshape handling in the md subsystem when suspending an md device during direct I/O across the reshape position. A local user can freeze reshape and write md/suspend_lo or md/suspend_hi to trigger a deadlock and cause a denial of service.
The issue occurs because I/O can wait for reshape progress while still holding an active_io reference, preventing suspend from completing if reshape is already frozen or interrupted.
How to mitigate CVE-2026-53123
Install security update from vendor's repository.