SB2026062536 - Improper locking in Linux kernel md driver

Description

This security bulletin contains information about 1 vulnerability.

1) Improper locking (CVE-ID: CVE-2026-53123)

CWE-ID: CWE-667 - Improper Locking

CVSSv4: 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

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.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/8ae3e14d7f3df58f7f49c02d74344e3dcd5f84f0
• https://git.kernel.org/stable/c/8b6a72420821e6da2cab6a69d5233500d2698b93
• https://git.kernel.org/stable/c/cf86bb53b9c92354904a328e947a05ffbfdd1840
• https://git.kernel.org/stable/c/ff6b93410192b812d73cc54062529715b2dc849f