CVE-2025-21846
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| rhel | 9 | fixed | |
| sles | affected | | |
| rocky | 9 | fixed | |
| debian | bookworm | fixed | 6.1.133-1 |
| debian | bullseye | fixed | 5.10.237-1 |
| debian | forky | fixed | 6.12.17-1 |
| debian | sid | fixed | 6.12.17-1 |
| debian | trixie | fixed | 6.12.17-1 |
| linux-kernel | affected | 6.1.130 | |
| linux-kernel | 6.14 | affected | |
| almalinux | 9 | fixed | kernel-doc-5.14.0-611.5.1.el9_7.noarch.rpm |
References
- https://access.redhat.com/errata/RHSA-2025:20518
- https://git.kernel.org/stable/c/56d5f3eba3f5de0efdd556de4ef381e109b973a9
- https://git.kernel.org/stable/c/5a59ced8ffc71973d42c82484a719c8f6ac8f7f7
- https://git.kernel.org/stable/c/5c928e14a2ccd99462f2351ead627b58075bb736
- https://git.kernel.org/stable/c/5d5b936cfa4b0d5670ca7420ef165a074bc008eb
- https://git.kernel.org/stable/c/5ee8da9bea70dda492d61f075658939af33d8410
- https://git.kernel.org/stable/c/8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735e
- https://git.kernel.org/stable/c/a8136afca090412a36429cb6c2543c714d9c0f84
- https://git.kernel.org/stable/c/b03782ae707cc45e65242c7cddd8e28f1c22cde5
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://www.suse.com/security/cve/CVE-2025-21846.html
- https://errata.rockylinux.org/RLSA-2025:20518
- https://security-tracker.debian.org/tracker/CVE-2025-21846
- https://bugzilla.redhat.com/2298169
- https://bugzilla.redhat.com/2312077
- https://bugzilla.redhat.com/2313092
- https://bugzilla.redhat.com/2320172
- https://bugzilla.redhat.com/2320259
- https://bugzilla.redhat.com/2320455
- https://bugzilla.redhat.com/2320616
- https://bugzilla.redhat.com/2320722
- https://bugzilla.redhat.com/2324549
- https://bugzilla.redhat.com/2327203
CWEs
CWE-476
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.