Linux hwe edge: In the Linux kernel, the following vulnerability has been resolved: kernfs: fix xattr race condition with multiple superblocks Multiple superblocks… (CVE-2026-74343)
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
AI Analysis
Technical Summary
CVE-2026-74343 addresses a race condition in the Linux kernel's kernfs subsystem where multiple superblocks with different namespaces can share the same kernfs_node, causing multiple inodes from different superblocks to reference the same xattrs structure. The existing per-inode locks were insufficient to serialize concurrent extended attribute (xattr) modifications, leading to potential race conditions in simple_xattr_set(). The vulnerability is mitigated by protecting xattr operations with a hashed mutex array (kernfs_locks->node_mutex[]) that provides scalable per-node serialization without additional memory overhead. The patch renames and extends the locking mechanism and updates relevant kernel code and documentation accordingly.
Potential Impact
The vulnerability could allow concurrent xattr modifications on shared kernfs_nodes to interfere with each other, potentially leading to data corruption or inconsistent extended attribute states. There is no information about exploitation in the wild or direct security impact such as privilege escalation or denial of service provided in the data.
Mitigation Recommendations
A fix has been implemented in the Linux kernel that protects xattr operations with a hashed mutex array to serialize concurrent modifications safely. Users should apply the official kernel updates that include this patch. Since no vendor advisory or patch links are provided, check the Linux kernel official repositories or distributions for the relevant fix. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
Linux hwe edge: In the Linux kernel, the following vulnerability has been resolved: kernfs: fix xattr race condition with multiple superblocks Multiple superblocks… (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
CVSS v3.1
Score 7.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-74343 addresses a race condition in the Linux kernel's kernfs subsystem where multiple superblocks with different namespaces can share the same kernfs_node, causing multiple inodes from different superblocks to reference the same xattrs structure. The existing per-inode locks were insufficient to serialize concurrent extended attribute (xattr) modifications, leading to potential race conditions in simple_xattr_set(). The vulnerability is mitigated by protecting xattr operations with a hashed mutex array (kernfs_locks->node_mutex[]) that provides scalable per-node serialization without additional memory overhead. The patch renames and extends the locking mechanism and updates relevant kernel code and documentation accordingly.
Potential Impact
The vulnerability could allow concurrent xattr modifications on shared kernfs_nodes to interfere with each other, potentially leading to data corruption or inconsistent extended attribute states. There is no information about exploitation in the wild or direct security impact such as privilege escalation or denial of service provided in the data.
Mitigation Recommendations
A fix has been implemented in the Linux kernel that protects xattr operations with a hashed mutex array to serialize concurrent modifications safely. Users should apply the official kernel updates that include this patch. Since no vendor advisory or patch links are provided, check the Linux kernel official repositories or distributions for the relevant fix. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-rxfr-7h9v-g4vx
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-74343"]
Threat ID: 6a808b6abf8831d5394f6988
Added to database: 08/15/2026, 15:53:14 UTC
Last enriched: 08/15/2026, 16:07:16 UTC
Last updated: 09/30/2026, 06:54:41 UTC
Views: 62
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.