CVE-2026-53125

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

md: fix array_state=clear sysfs deadlock

When "clear" is written to array_state, md_attr_store() breaks sysfs

active protection so the array can delete itself from its own sysfs

store method.

However, md_attr_store() currently drops the mddev reference before

calling sysfs_unbreak_active_protection(). Once do_md_stop(..., 0)

has made the mddev eligible for delayed deletion, the temporary

kobject reference taken by sysfs_break_active_protection() can become

the last kobject reference protecting the md kobject.

That allows sysfs_unbreak_active_protection() to drop the last

kobject reference from the current sysfs writer context. kobject

teardown then recurses into kernfs removal while the current sysfs

node is still being unwound, and lockdep reports recursive locking on

kn->active with kernfs_drain() in the call chain.

Reproducer on an existing level:

1. Create an md0 linear array and activate it:

mknod /dev/md0

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References