CVE-2026-93261: Linux kernel · locking/lockdep: Fix NULL pointer dereference in __lock_set_class()
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 24 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2026-93261 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-93261 (opens in a new tab)
- git.kernel.org/stable/c/f56e54fd24f05e9de528fcb77f6084f80c8066ce (opens in a new tab)
- git.kernel.org/stable/c/59a5c7dd331a3dab48100e1ef8e9bb4f9132a2b2 (opens in a new tab)
- git.kernel.org/stable/c/5c3bff6cf26e6a54fbf8b893a879c32824d2d50d (opens in a new tab)
- git.kernel.org/stable/c/f6093ff67ea6e347574819ed23e96e0f82a25ffc (opens in a new tab)
- git.kernel.org/stable/c/9be10f49dfc2e4b472b3a5f346483b67374774b8 (opens in a new tab)
- git.kernel.org/stable/c/7577e00b9ab506202b9f1a33de3cc8cc6413a4db (opens in a new tab)
- git.kernel.org/stable/c/e7c69c6695d84220847cca62a45e879e71e79e9d (opens in a new tab)
- git.kernel.org/stable/c/b2113dcd8238bf00ce37a34e67b29cf31d32a545 (opens in a new tab)