CVE-2026-93261

/// Technical description

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

locking/lockdep: Fix NULL pointer dereference in __lock_set_class()

register_lock_class() can return NULL when the lock class pool is

exhausted, graph_lock() fails, or key validation fails. However,

__lock_set_class() uses the return value directly in pointer arithmetic

without a NULL check:

class = register_lock_class(lock, subclass, 0);

hlock->class_idx = class - lock_classes;

If class is NULL, this computes a wild offset that corrupts

hlock->class_idx. The subsequent reacquire_held_locks() call will

invoke hlock_class() with this corrupted index, leading to a NULL or

out-of-bounds pointer dereference.

Add the missing NULL check, consistent with how __lock_acquire() already

handles this case at the same call site.

/// 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