Vulnerability in Linux

[ Description ]Official 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.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• CERT-FR9 Oct 2026CERTFR-2026-AVI-1289

  Multiple vulnerabilities in the Debian LTS Linux kernel Translated from French

  Multiple vulnerabilities have been discovered in the Debian LTS Linux kernel. Some of them allow an attacker to cause privilege escalation, a breach of data confidentiality and denial of service.

  CVE-2025-38237CVE-2025-39833CVE-2025-39925+1311 more CVEs
• CERT-FR2 Oct 2026CERTFR-2026-AVI-1253

  Multiple vulnerabilities in the Debian Linux kernel Translated from French

  Multiple vulnerabilities have been discovered in the Debian Linux kernel. Some of them allow an attacker to cause privilege escalation, a breach of data confidentiality and denial of service.

  CVE-2025-38237CVE-2025-39833CVE-2025-39925+1310 more CVEs
• BSI CERT-Bund24 Sep 2026WID-SEC-2026-3579

  Linux Kernel: Multiple vulnerabilities Translated from German

  CVE-2026-97615CVE-2026-97978CVE-2026-98127+590 more CVEs

[ References ]References

• git.kernel.org/stable/c/59a5c7dd331a3dab48100e1ef8e9bb4f9132a2b2
• git.kernel.org/stable/c/5c3bff6cf26e6a54fbf8b893a879c32824d2d50d
• git.kernel.org/stable/c/7577e00b9ab506202b9f1a33de3cc8cc6413a4db
• git.kernel.org/stable/c/9be10f49dfc2e4b472b3a5f346483b67374774b8
• git.kernel.org/stable/c/b2113dcd8238bf00ce37a34e67b29cf31d32a545
• git.kernel.org/stable/c/e7c69c6695d84220847cca62a45e879e71e79e9d
• git.kernel.org/stable/c/f56e54fd24f05e9de528fcb77f6084f80c8066ce
• git.kernel.org/stable/c/f6093ff67ea6e347574819ed23e96e0f82a25ffc