CVE-2026-64390
ksmbd: track the connection owning a byte-range lock
Description
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.
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
July 25, 2026, 10:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-64390
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Track connection owning each lock's clist entry.
- Hold reference to connection while entry is linked.
- Use connection and its spinlock for unlock operations.
- Assign new connection owner on durable reconnect.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64390.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64390 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64390
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64390 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64390 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'f5a544e3bab78142207e0242d22442db85ba1eff', 'lessThan': '22d38cf75b556c20b039743bdf3654d535b858be', 'versionType': 'git'}, {'status': 'affected', 'version': 'f5a544e3bab78142207e0242d22442db85ba1eff', 'lessThan': '66eb3643164e5e1029907793926c132f8b5c6148', 'versionType': 'git'}, {'status': 'affected', 'version': 'f5a544e3bab78142207e0242d22442db85ba1eff', 'lessThan': 'ea5c9bf99f626a15cc59f645dc895f2b3f01992e', 'versionType': 'git'}, {'status': 'affected', 'version': 'f5a544e3bab78142207e0242d22442db85ba1eff', 'lessThan': 'fe20d492a69a6f79e637f438072b212e21ed3b78', 'versionType': 'git'}, {'status': 'affected', 'version': 'f5a544e3bab78142207e0242d22442db85ba1eff', 'lessThan': '427faaa52b0b399940c1a88065a5c310d10dad15', 'versionType': 'git'}, {'status': 'affected', 'version': 'f5a544e3bab78142207e0242d22442db85ba1eff', 'lessThan': '5fecc15a30cb9ebd310f7b52c1ab607edcea78f6', 'versionType': 'git'}, {'status': 'affected', 'version': 'f5a544e3bab78142207e0242d22442db85ba1eff', 'lessThan': 'c1016dd1d8b2bcd1158bbaabe94a31bb7e7431fb', 'versionType': 'git'}], 'programFiles': ['fs/smb/server/smb2pdu.c', 'fs/smb/server/vfs_cache.c', 'fs/smb/server/vfs_cache.h'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/smb/server/smb2pdu.c', 'fs/smb/server/vfs_cache.c', 'fs/smb/server/vfs_cache.h'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/22d38cf75b556c20b039743bdf3654d535b858be Added Reference https://git.kernel.org/stable/c/427faaa52b0b399940c1a88065a5c310d10dad15 Added Reference https://git.kernel.org/stable/c/5fecc15a30cb9ebd310f7b52c1ab607edcea78f6 Added Reference https://git.kernel.org/stable/c/66eb3643164e5e1029907793926c132f8b5c6148 Added Reference https://git.kernel.org/stable/c/c1016dd1d8b2bcd1158bbaabe94a31bb7e7431fb Added Reference https://git.kernel.org/stable/c/ea5c9bf99f626a15cc59f645dc895f2b3f01992e Added Reference https://git.kernel.org/stable/c/fe20d492a69a6f79e637f438072b212e21ed3b78