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.
History

Fri, 14 Mar 2025 02:30:00 +0000


Thu, 13 Mar 2025 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-476
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Thu, 13 Mar 2025 13:00:00 +0000


Wed, 12 Mar 2025 09:45:00 +0000

Type Values Removed Values Added
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.
Title acct: perform last write from workqueue
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-03-12T09:42:02.635Z

Updated: 2025-03-24T15:41:18.292Z

Reserved: 2024-12-29T08:45:45.778Z

Link: CVE-2025-21846

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-03-12T10:15:16.960

Modified: 2025-03-13T16:28:27.520

Link: CVE-2025-21846

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-03-12T00:00:00Z

Links: CVE-2025-21846 - Bugzilla