Improper locking in Linux kernel - CVE-2026-53125

Vulnerability identifier: #VU135164

CSH Severity: Low

CVSS v4: 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]

CVE-ID: CVE-2026-53125

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper lock handling in md_attr_store() when processing a write of "clear" to the array_state sysfs attribute. A local user can write "clear" to the array_state sysfs entry to cause a denial of service.

The issue is triggered during md array teardown from the sysfs write path and results in recursive locking on kn->active.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/2aa72276fab9851dbd59c2daeb4b590c5a113908
• https://git.kernel.org/stable/c/62c44566da7493ee48ef17e8507bb798338a07cb
• https://git.kernel.org/stable/c/92ad0ec509ffb188d8f849b63148664df37b4a52

• Improper locking in Linux kernel md driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia