Vulnerability in Linux

CVE-2025-21672

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

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.001 (2.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 2.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-21672: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

  • Linux — versions f94f70d39cc2d54079ebae934862198516315db2, 6.8, 0
  • Linux Kernel — versions 6.13

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21672?
CVE-2025-21672 is a medium-severity vulnerability in Linux, classified under Improper Locking. CVSS score: 5.5/10. Published 2025-01-31.
How severe is CVE-2025-21672?
Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2025-21672 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.