VULNERABILITY INTELLIGENCE

CVE-2025-21846

CVSS score5.5 MEDIUM
EPSS probability0.25%
CISA KEVNot currently listed
Published2025-03-12
Last modified2026-10-15
CVSS vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Description

In the Linux kernel, the following vulnerability has been resolved: acct: perform last write from workqueue In [1] it was reported that the acct(2) system call can be used to trigger NULL deref in cases where it is set to write to a file that triggers an internal lookup. This can e.g., happen when pointing acc(2) to /sys/power/resume. At the point the where the write to this file happens the calling task has already exited and called exit_fs(). A lookup will thus trigger a NULL-deref when accessing current->fs. Reorganize the code so that the the final write happens from the workqueue but with the caller's credentials. This preserves the (strange) permission model and has almost no regression risk. This api should stop to exist though.

Weakness classification

  • nvd@nist.gov: CWE-476
  • 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-476

Primary references