CVE-2025-21846
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…
Does this matter?
Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.24% probability · 15th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/56d5f3eba3f5de0efdd556de4ef381e109b973a9Patch
- https://git.kernel.org/stable/c/5a59ced8ffc71973d42c82484a719c8f6ac8f7f7Patch
- https://git.kernel.org/stable/c/5c928e14a2ccd99462f2351ead627b58075bb736Patch
- https://git.kernel.org/stable/c/5d5b936cfa4b0d5670ca7420ef165a074bc008ebPatch
- https://git.kernel.org/stable/c/5ee8da9bea70dda492d61f075658939af33d8410Patch
- https://git.kernel.org/stable/c/8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735ePatch
- https://git.kernel.org/stable/c/a8136afca090412a36429cb6c2543c714d9c0f84Patch
- https://git.kernel.org/stable/c/b03782ae707cc45e65242c7cddd8e28f1c22cde5Patch
- 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-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.