CVE-2026-64390

High

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.

Package Linux Kernel
Published 2026-07-25
Last modified 2026-09-04
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

8.8

out of 10
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 5.15 and later are affected. Fixed in 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.4, 7.2 and their respective stable series.

Affected from
≥ 5.15
Fixed in
✓ 5.15.212 5.15.x ✓ 6.1.178 6.1.x ✓ 6.6.145 6.6.x ✓ 6.12.97 6.12.x ✓ 6.18.40 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2

References

7 total
Showing 5 of 7 references View all on NVD

Frequently asked questions

  • What is CVE-2026-64390?

    CVE-2026-64390 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10 . It affects Linux kernel versions from 5.15 onward and has been patched in 5.15.212, 6.1.178, 6.6.145 and others. CVE-2026-64390 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-64390?

    CVE-2026-64390 has a CVSS score of 8.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-64390?

    Yes. CVE-2026-64390 has been patched. Fixed versions include 5.15.212, 6.1.178, 6.6.145 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-64390 actively exploited?

    No. CVE-2026-64390 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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