{"api_version":"1","generated_at":"2026-08-15T08:45:06+00:00","cve":"CVE-2026-74343","urls":{"html":"https://cve.report/CVE-2026-74343","api":"https://cve.report/api/cve/CVE-2026-74343.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74343","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74343"},"summary":{"title":"kernfs: fix xattr race condition with multiple superblocks","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nkernfs: fix xattr race condition with multiple superblocks\n\nMultiple superblocks with different namespaces can share the same\nkernfs_node when kernfs_test_super() finds a matching root but\ndifferent namespace. This means multiple inodes from different\nsuperblocks can reference the same kernfs_node->iattr->xattrs\nstructure.\n\nThe VFS layer only holds per-inode locks during xattr operations,\nwhich is insufficient to serialize concurrent xattr modifications on\nthe shared kernfs_node. This can lead to race conditions in\nsimple_xattr_set() where the lookup->replace/remove sequence is not\natomic with respect to operations from other superblocks.\n\nFix this by protecting xattr operations with the existing hashed\nkernfs_locks->open_file_mutex[] array, which is already used to\nprotect per-node open file data. The hashed mutex array provides\nscalable per-node serialization (scaled by CPU count, up to 1024 locks\non 32+ CPU systems) with zero memory overhead.\n\nChanges:\n- Rename open_file_mutex[] to node_mutex[] to reflect dual purpose\n- Add kernfs_node_lock_ptr() and kernfs_node_lock() helpers\n- Protect simple_xattr_set() calls in kernfs_xattr_set() and\n  kernfs_vfs_user_xattr_set() with the hashed mutex\n- Update file.c to use new helpers via compatibility wrappers\n- Update documentation to explain the extended lock usage","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:22:35","updated_at":"2026-08-15 06:22:35"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/6a07814ff643b5c8e1353d8c6229f52fde205cde","name":"https://git.kernel.org/stable/c/6a07814ff643b5c8e1353d8c6229f52fde205cde","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bf53db51359939755084d08156684ed649489592","name":"https://git.kernel.org/stable/c/bf53db51359939755084d08156684ed649489592","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74343","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74343","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b32c4a213698ab351b44da2fd1b2a5976c7fa033 bf53db51359939755084d08156684ed649489592 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b32c4a213698ab351b44da2fd1b2a5976c7fa033 6a07814ff643b5c8e1353d8c6229f52fde205cde git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/kernfs/file.c","fs/kernfs/inode.c","fs/kernfs/kernfs-internal.h","fs/kernfs/mount.c","include/linux/kernfs.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"bf53db51359939755084d08156684ed649489592","status":"affected","version":"b32c4a213698ab351b44da2fd1b2a5976c7fa033","versionType":"git"},{"lessThan":"6a07814ff643b5c8e1353d8c6229f52fde205cde","status":"affected","version":"b32c4a213698ab351b44da2fd1b2a5976c7fa033","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/kernfs/file.c","fs/kernfs/inode.c","fs/kernfs/kernfs-internal.h","fs/kernfs/mount.c","include/linux/kernfs.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nkernfs: fix xattr race condition with multiple superblocks\n\nMultiple superblocks with different namespaces can share the same\nkernfs_node when kernfs_test_super() finds a matching root but\ndifferent namespace. This means multiple inodes from different\nsuperblocks can reference the same kernfs_node->iattr->xattrs\nstructure.\n\nThe VFS layer only holds per-inode locks during xattr operations,\nwhich is insufficient to serialize concurrent xattr modifications on\nthe shared kernfs_node. This can lead to race conditions in\nsimple_xattr_set() where the lookup->replace/remove sequence is not\natomic with respect to operations from other superblocks.\n\nFix this by protecting xattr operations with the existing hashed\nkernfs_locks->open_file_mutex[] array, which is already used to\nprotect per-node open file data. The hashed mutex array provides\nscalable per-node serialization (scaled by CPU count, up to 1024 locks\non 32+ CPU systems) with zero memory overhead.\n\nChanges:\n- Rename open_file_mutex[] to node_mutex[] to reflect dual purpose\n- Add kernfs_node_lock_ptr() and kernfs_node_lock() helpers\n- Protect simple_xattr_set() calls in kernfs_xattr_set() and\n  kernfs_vfs_user_xattr_set() with the hashed mutex\n- Update file.c to use new helpers via compatibility wrappers\n- Update documentation to explain the extended lock usage"}],"providerMetadata":{"dateUpdated":"2026-08-15T05:58:32.577Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/bf53db51359939755084d08156684ed649489592"},{"url":"https://git.kernel.org/stable/c/6a07814ff643b5c8e1353d8c6229f52fde205cde"}],"title":"kernfs: fix xattr race condition with multiple superblocks","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74343","datePublished":"2026-08-15T05:58:32.577Z","dateReserved":"2026-08-15T05:44:03.886Z","dateUpdated":"2026-08-15T05:58:32.577Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:22:35","lastModifiedDate":"2026-08-15 06:22:35","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74343","Ordinal":"1","Title":"kernfs: fix xattr race condition with multiple superblocks","CVE":"CVE-2026-74343","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74343","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nkernfs: fix xattr race condition with multiple superblocks\n\nMultiple superblocks with different namespaces can share the same\nkernfs_node when kernfs_test_super() finds a matching root but\ndifferent namespace. This means multiple inodes from different\nsuperblocks can reference the same kernfs_node->iattr->xattrs\nstructure.\n\nThe VFS layer only holds per-inode locks during xattr operations,\nwhich is insufficient to serialize concurrent xattr modifications on\nthe shared kernfs_node. This can lead to race conditions in\nsimple_xattr_set() where the lookup->replace/remove sequence is not\natomic with respect to operations from other superblocks.\n\nFix this by protecting xattr operations with the existing hashed\nkernfs_locks->open_file_mutex[] array, which is already used to\nprotect per-node open file data. The hashed mutex array provides\nscalable per-node serialization (scaled by CPU count, up to 1024 locks\non 32+ CPU systems) with zero memory overhead.\n\nChanges:\n- Rename open_file_mutex[] to node_mutex[] to reflect dual purpose\n- Add kernfs_node_lock_ptr() and kernfs_node_lock() helpers\n- Protect simple_xattr_set() calls in kernfs_xattr_set() and\n  kernfs_vfs_user_xattr_set() with the hashed mutex\n- Update file.c to use new helpers via compatibility wrappers\n- Update documentation to explain the extended lock usage","Type":"Description","Title":"kernfs: fix xattr race condition with multiple superblocks"}]}}}