CVE Catalog

CVE-2026-64390

HighCVSS 8.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.47%

38th percentile - higher than 38% of all known CVEs

Summary

In the Linux kernel, the ksmbd filesystem has a lock management issue with SMB3 multichannel. A byte-range lock can be removed from the connection list using the wrong spinlock, leading to access to freed objects during concurrent list traversal.

Risk Assessment

An attacker using SMB3 multichannel can cause a system crash or potentially execute arbitrary code by manipulating file locks.

Recommendation

Apply the Linux kernel patch that records the connection owning the lock and uses the correct spinlock when removing the lock from the list.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ksmbd: track the connection owning a byte-range lock SMB2_LOCK adds each granted byte-range lock to both the file lock list and the lock list of the connection which handled the request. The final close and durable handle paths, however, remove the connection list entry while holding fp->conn->llist_lock. With SMB3 multichannel, the connection handling the LOCK request can be different from the connection which opened the file. The entry can therefore be removed under a different spinlock from the one protecting the list it belongs to. A concurrent traversal can then access freed struct ksmbd_lock and struct file_lock objects. Record the connection owning each lock's clist entry and hold a reference to it while the entry is linked. Use that connection and its llist_lock for unlock, rollback, close, and durable preserve. Durable reconnect assigns the new connection as the owner when publishing the locks again.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS