CVE-2025-21672

Medium

In the Linux kernel, the following vulnerability has been resolved: afs: Fix merge preference rule failure condition syzbot reported a lock held when returning to userspace[1]. This is because if argc is less than 0 and the function returns directly, the held inode lock is not released. Fix this by store the error in ret and jump to done to clean up instead of returning directly. [dh: Modified Lizhi Xu's original patch to make it honour the error code from afs_split_string()] [1] WARNING: lock held when returning to user space! 6.13.0-rc3-syzkaller-00209-g499551201b5f #0 Not tainted ------------------------------------------------ syz-executor133/5823 is leaving the kernel with locks still held! 1 lock held by syz-executor133/5823: #0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] #0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: afs_proc_addr_prefs_write+0x2bb/0x14e0 fs/afs/addr_prefs.c:388

Package Linux Kernel
Published 2025-01-31
Last modified 2025-10-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

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

Weakness type

CWE-667

CVE-2025-21672 is a Improper Locking vulnerability

What is Improper Locking?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.8 and later are affected. Fixed in 6.12.11, 6.13 and their respective stable series.

Affected from
≥ 6.8
Fixed in
✓ 6.12.11 6.12.x ✓ 6.13

References

The following references provide additional information about CVE-2025-21672 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2025-21672?

    CVE-2025-21672 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 6.8 onward and has been patched in 6.12.11 and 6.13. CVE-2025-21672 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-21672?

    CVE-2025-21672 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2025-21672?

    Yes — CVE-2025-21672 has been patched. Fixed versions include 6.12.11 and 6.13. If you are running Linux kernel 6.8 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-21672 actively exploited?

    No — CVE-2025-21672 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Improper Locking (CWE-667)?

    The product does not properly acquire or release a lock, which can lead to unexpected behaviour. View CWE-667 on MITRE CWE →

Back to
All CVEs
View on
NVD / NIST