{"apiVersion":"1.0","identifier":"CVE-2026-74343","description":"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","publishedAt":"2026-08-15T06:22:35","lastModifiedAt":"2026-08-17T06:19:28","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74343","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.0012,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74343","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74343","en":"https://www.redsauce.net/en/cves/CVE-2026-74343","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74343","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74343","de":"https://www.redsauce.net/de/cves/CVE-2026-74343","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74343","el":"https://www.redsauce.net/el/cves/CVE-2026-74343"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74343"}}