CVE-2025-21846
Linux Kernel: acct NULL Deref Vulnerability in sysctl
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.
INFO
Published Date :
March 12, 2025, 10:15 a.m.
Last Modified :
March 13, 2025, 4:28 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-21846.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2025-21846 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-21846 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Mar. 13, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-476 Added CPE Configuration OR *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:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 from (excluding) 6.13.5 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 from (excluding) 6.6.80 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 from (excluding) 6.12.17 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.12 from (excluding) 6.1.130 Added Reference Type kernel.org: https://git.kernel.org/stable/c/56d5f3eba3f5de0efdd556de4ef381e109b973a9 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/5a59ced8ffc71973d42c82484a719c8f6ac8f7f7 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/5c928e14a2ccd99462f2351ead627b58075bb736 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/5d5b936cfa4b0d5670ca7420ef165a074bc008eb Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/5ee8da9bea70dda492d61f075658939af33d8410 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735e Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a8136afca090412a36429cb6c2543c714d9c0f84 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b03782ae707cc45e65242c7cddd8e28f1c22cde5 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 13, 2025
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/5d5b936cfa4b0d5670ca7420ef165a074bc008eb Added Reference https://git.kernel.org/stable/c/8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735e Added Reference https://git.kernel.org/stable/c/b03782ae707cc45e65242c7cddd8e28f1c22cde5 -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 12, 2025
Action Type Old Value New Value 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. Added Reference https://git.kernel.org/stable/c/56d5f3eba3f5de0efdd556de4ef381e109b973a9 Added Reference https://git.kernel.org/stable/c/5a59ced8ffc71973d42c82484a719c8f6ac8f7f7 Added Reference https://git.kernel.org/stable/c/5c928e14a2ccd99462f2351ead627b58075bb736 Added Reference https://git.kernel.org/stable/c/5ee8da9bea70dda492d61f075658939af33d8410 Added Reference https://git.kernel.org/stable/c/a8136afca090412a36429cb6c2543c714d9c0f84
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-21846 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-21846
weaknesses.