CVE-2026-93261
locking/lockdep: Fix NULL pointer dereference in __lock_set_class()
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.
INFO
Published Date :
Sept. 24, 2026, 4:17 p.m.
Last Modified :
Sept. 24, 2026, 4:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Add NULL check for register_lock_class return.
- Ensure class is not NULL before pointer arithmetic.
- Update the Linux kernel to the patched version.
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CWE - Common Weakness Enumeration
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associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
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weaknesses.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 24, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93261.json">CVE-2026-93261</a> Added Reference https://git.kernel.org/stable/c/59a5c7dd331a3dab48100e1ef8e9bb4f9132a2b2 Added Reference https://git.kernel.org/stable/c/5c3bff6cf26e6a54fbf8b893a879c32824d2d50d Added Reference https://git.kernel.org/stable/c/7577e00b9ab506202b9f1a33de3cc8cc6413a4db Added Reference https://git.kernel.org/stable/c/9be10f49dfc2e4b472b3a5f346483b67374774b8 Added Reference https://git.kernel.org/stable/c/b2113dcd8238bf00ce37a34e67b29cf31d32a545 Added Reference https://git.kernel.org/stable/c/e7c69c6695d84220847cca62a45e879e71e79e9d Added Reference https://git.kernel.org/stable/c/f56e54fd24f05e9de528fcb77f6084f80c8066ce Added Reference https://git.kernel.org/stable/c/f6093ff67ea6e347574819ed23e96e0f82a25ffc