ksmbd: track the connection owning a byte-range lock
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.15 and later | 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.4, 7.2 | Patch available | CNA |
- Linux VendorLinux Affected 5.15 and later Fixed in 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.4, 7.2 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.15 to before 5.15.212; 5.16 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.97; 6.13 to before 6.18.40; 6.19 to before 7.1.4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.15 to before 5.15.212; 5.16 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.97; 6.13 to before 6.18.40; 6.19 to before 7.1.4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.4, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64390
- 2026-10-03 Alias added: GHSA-pgh2-g34p-4j6m
- 2026-10-20 Affected versions changed · Red Hat
References
Patch 7
- https://git.kernel.org/stable/c/22d38cf75b556c20b039743bdf3654d535b858be
- https://git.kernel.org/stable/c/66eb3643164e5e1029907793926c132f8b5c6148
- https://git.kernel.org/stable/c/ea5c9bf99f626a15cc59f645dc895f2b3f01992e
- https://git.kernel.org/stable/c/fe20d492a69a6f79e637f438072b212e21ed3b78
- https://git.kernel.org/stable/c/427faaa52b0b399940c1a88065a5c310d10dad15
- https://git.kernel.org/stable/c/5fecc15a30cb9ebd310f7b52c1ab607edcea78f6
- https://git.kernel.org/stable/c/c1016dd1d8b2bcd1158bbaabe94a31bb7e7431fb
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Sources
- CVE-2026-64390 · CVE Program
- CVE-2026-64390 · NVD
- FIRST EPSS
- GHSA-pgh2-g34p-4j6m · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64390 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences