Bug 2507113 (CVE-2026-64390) - CVE-2026-64390 kernel: ksmbd: track the connection owning a byte-range lock
Summary: CVE-2026-64390 kernel: ksmbd: track the connection owning a byte-range lock
Keywords:
Status: NEW
Alias: CVE-2026-64390
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-25 10:05 UTC by OSIDB Bzimport
Modified: 2026-07-30 04:58 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-07-25 10:05:42 UTC
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.


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