CVE-2026-74343
Analyse NVD en cours
In the Linux kernel, the following vulnerability has been resolved: kernfs: fix xattr race condition with multiple superblocks Multiple superblocks with different namespaces can share the same kernfs_node when kernfs_test_super() finds a matching root but different namespace. This means multiple inodes from different superblocks can reference the same kernfs_node->iattr->xattrs structure. The VFS layer only holds per-inode locks during xattr operations, which is insufficient to serialize concurrent xattr modifications on the shared kernfs_node. This can lead to race conditions in simple_xattr_set() where the lookup->replace/remove sequence is not atomic with respect to operations from other superblocks. Fix this by protecting xattr operations with the existing hashed kernfs_locks->open_file_mutex[] array, which is already used to protect per-node open file data. The hashed mutex array provides scalable per-node serialization (scaled by CPU count, up to 1024 locks on 32+ CPU systems) with zero memory overhead. Changes: - Rename open_file_mutex[] to node_mutex[] to reflect dual purpose - Add kernfs_node_lock_ptr() and kernfs_node_lock() helpers - Protect simple_xattr_set() calls in kernfs_xattr_set() and kernfs_vfs_user_xattr_set() with the hashed mutex - Update file.c to use new helpers via compatibility wrappers - Update documentation to explain the extended lock usage
Ce que ça veut dire
- Exposition
- Exploitable avec un accès local à la machine, avec un compte utilisateur ordinaire et sans action de la victime.
- Impact
- Un attaquant peut lire des données sensibles, modifier ou détruire des données et mettre le service hors ligne.
- Probabilité
- Le score EPSS reste bas : rien n’annonce une exploitation imminente, ce qui ne dispense pas de corriger.
À faireÀ intégrer au prochain cycle de correctifs.
Lecture automatique du vecteur CVSS, du type de faiblesse (CWE) et du score EPSS. La description technique ci-dessus reste celle publiée par le NIST, en anglais.