CVE-2026-90162
ksmbd: defer publishing granted locks to prevent UAF/double-free race
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: defer publishing granted locks to prevent UAF/double-free race In smb2_lock(), mid-batch granted locks are published to connection-wide (conn->lock_list) and file-wide (fp->lock_list) lists immediately upon vfs_lock_file() success, while also remaining tracked on the stack-local rollback_list. If a subsequent element in the same SMB2_LOCK request array fails validation or execution, the thread jumps to out: and walks rollback_list to undo previously granted locks. However, because the granted lock was already published to conn->lock_list, a concurrent UNLOCK request on the same connection can find the lock object and kfree() it before the rollback loop executes. When the granting thread subsequently walks rollback_list, it dereferences and frees the already-freed ksmbd_lock structure, resulting in a Use-After-Free and Double-Free (on both ksmbd_lock and struct file_lock). Fix this by deferring the publication of granted locks to conn->lock_list and fp->lock_list until after the entire array of lock elements has been processed without error. Mid-batch grants remain tracked exclusively on the request-local rollback_list until the whole batch succeeds, eliminating the race window.
INFO
Published Date :
Sept. 17, 2026, 5:17 p.m.
Last Modified :
Sept. 18, 2026, 6:17 p.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Apply kernel patches to defer lock publication.
- Update the Linux kernel to the latest version.
- Test thoroughly after applying the patch.
- Review kernel locking mechanisms.
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-2026-90162.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/29f74f0f2e6df3b393b7b66e810136d0c64e3c59 | |
| https://git.kernel.org/stable/c/a1d26dfb32919088e3638dca01068df3c4507433 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-90162 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-2026-90162
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-2026-90162 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-90162 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.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 18, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 17, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: ksmbd: defer publishing granted locks to prevent UAF/double-free race In smb2_lock(), mid-batch granted locks are published to connection-wide (conn->lock_list) and file-wide (fp->lock_list) lists immediately upon vfs_lock_file() success, while also remaining tracked on the stack-local rollback_list. If a subsequent element in the same SMB2_LOCK request array fails validation or execution, the thread jumps to out: and walks rollback_list to undo previously granted locks. However, because the granted lock was already published to conn->lock_list, a concurrent UNLOCK request on the same connection can find the lock object and kfree() it before the rollback loop executes. When the granting thread subsequently walks rollback_list, it dereferences and frees the already-freed ksmbd_lock structure, resulting in a Use-After-Free and Double-Free (on both ksmbd_lock and struct file_lock). Fix this by deferring the publication of granted locks to conn->lock_list and fp->lock_list until after the entire array of lock elements has been processed without error. Mid-batch grants remain tracked exclusively on the request-local rollback_list until the whole batch succeeds, eliminating the race window. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/90xxx/CVE-2026-90162.json">CVE-2026-90162</a> Added Reference https://git.kernel.org/stable/c/29f74f0f2e6df3b393b7b66e810136d0c64e3c59 Added Reference https://git.kernel.org/stable/c/a1d26dfb32919088e3638dca01068df3c4507433