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Review reviewHigh

CVE-2026-64390

Linux

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...

CVSS
8.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.25
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 8.8

Vulnerability overview

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...

Affected product and versions

Product
Linux
Affected versions
>= f5a544e3bab78142207e0242d22442db85ba1eff < 22d38cf75b556c20b039743bdf3654d535b858be, >= f5a544e3bab78142207e0242d22442db85ba1eff < 66eb3643164e5e1029907793926c132f8b5c6148, >= f5a544e3bab78142207e0242d22442db85ba1eff < ea5c9bf99f626a15cc59f645dc895f2b3f01992e, >= f5a544e3bab78142207e0242d22442db85ba1eff < fe20d492a69a6f79e637f438072b212e21ed3b78, >= f5a544e3bab78142207e0242d22442db85ba1eff < 427faaa52b0b399940c1a88065a5c310d10dad15, >= f5a544e3bab78142207e0242d22442db85ba1eff < 5fecc15a30cb9ebd310f7b52c1ab607edcea78f6, >= f5a544e3bab78142207e0242d22442db85ba1eff < c1016dd1d8b2bcd1158bbaabe94a31bb7e7431fb, >= 5.15
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available