Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Race condition requires precise concurrent timing across multiple namespace-shared superblocks, warranting AC:H over the vendor-assigned AC:L.
Primary rating from Vendor (Linux).
CVSS VectorVendor: Linux
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
5DescriptionCVE.org
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
AnalysisAI
Race condition in the kernfs xattr subsystem of Linux kernel 7.1 and earlier allows local low-privileged users to corrupt shared xattr structures across multiple superblocks, resulting in high-impact confidentiality, integrity, and availability compromise. The flaw arises specifically in namespace-multiplexed environments where kernfs_test_super() allows distinct superblocks to share a single kernfs_node while VFS locking remains per-inode and therefore insufficient. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires a local user account with standard (low) privileges on a Linux system running kernel version 7.1 or earlier in the 7.x series (CVSS PR:L). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The vendor-assigned CVSS 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) reflects local exploitation with low privileges and full-system impact. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | A low-privileged local attacker on a Linux 7.1 host running a container runtime or Kubernetes node creates multiple user namespaces whose kernfs mounts resolve to shared kernfs_node entries. The attacker then spawns concurrent threads that simultaneously invoke setxattr and removexattr on the same kernfs-backed path from different namespace contexts, racing the non-atomic lookup-replace sequence inside simple_xattr_set() to corrupt the shared xattrs structure, potentially overwriting kernel memory or leaking sensitive xattr data from sibling namespaces. … |
| Remediation | The upstream fix is available via two stable kernel commits: https://git.kernel.org/stable/c/bf53db51359939755084d08156684ed649489592 and https://git.kernel.org/stable/c/6a07814ff643b5c8e1353d8c6229f52fde205cde. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, scan infrastructure for systems running Linux kernel 7.1 or earlier to establish patching scope and prioritize high-risk deployments. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
Same technique Information Disclosure
View allVendor StatusVendor
Share
External POC / Exploit Code
Leaving vuln.today
EUVD-2026-59490
GHSA-rxfr-7h9v-g4vx