CVE-2025-21846

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. 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 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.

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/56d5f3eba3f5de0efdd556de4ef381e109b973a9 Patch
https://git.kernel.org/stable/c/5a59ced8ffc71973d42c82484a719c8f6ac8f7f7 Patch
https://git.kernel.org/stable/c/5c928e14a2ccd99462f2351ead627b58075bb736 Patch
https://git.kernel.org/stable/c/5d5b936cfa4b0d5670ca7420ef165a074bc008eb Patch
https://git.kernel.org/stable/c/5ee8da9bea70dda492d61f075658939af33d8410 Patch
https://git.kernel.org/stable/c/8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735e Patch
https://git.kernel.org/stable/c/a8136afca090412a36429cb6c2543c714d9c0f84 Patch
https://git.kernel.org/stable/c/b03782ae707cc45e65242c7cddd8e28f1c22cde5 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
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:*:*:*:*:*:*
History

13 Mar 2025, 16:28

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/56d5f3eba3f5de0efdd556de4ef381e109b973a9 - () https://git.kernel.org/stable/c/56d5f3eba3f5de0efdd556de4ef381e109b973a9 - Patch
References () https://git.kernel.org/stable/c/5a59ced8ffc71973d42c82484a719c8f6ac8f7f7 - () https://git.kernel.org/stable/c/5a59ced8ffc71973d42c82484a719c8f6ac8f7f7 - Patch
References () https://git.kernel.org/stable/c/5c928e14a2ccd99462f2351ead627b58075bb736 - () https://git.kernel.org/stable/c/5c928e14a2ccd99462f2351ead627b58075bb736 - Patch
References () https://git.kernel.org/stable/c/5d5b936cfa4b0d5670ca7420ef165a074bc008eb - () https://git.kernel.org/stable/c/5d5b936cfa4b0d5670ca7420ef165a074bc008eb - Patch
References () https://git.kernel.org/stable/c/5ee8da9bea70dda492d61f075658939af33d8410 - () https://git.kernel.org/stable/c/5ee8da9bea70dda492d61f075658939af33d8410 - Patch
References () https://git.kernel.org/stable/c/8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735e - () https://git.kernel.org/stable/c/8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735e - Patch
References () https://git.kernel.org/stable/c/a8136afca090412a36429cb6c2543c714d9c0f84 - () https://git.kernel.org/stable/c/a8136afca090412a36429cb6c2543c714d9c0f84 - Patch
References () https://git.kernel.org/stable/c/b03782ae707cc45e65242c7cddd8e28f1c22cde5 - () https://git.kernel.org/stable/c/b03782ae707cc45e65242c7cddd8e28f1c22cde5 - Patch
CWE CWE-476
CPE cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
First Time Linux linux Kernel
Linux

13 Mar 2025, 13:15

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: acct: realizar la última escritura desde workqueue En [1] se informó que la llamada al sistema acct(2) se puede usar para activar una desreferencia NULL en los casos en que está configurada para escribir en un archivo que activa una búsqueda interna. Esto puede ocurrir, por ejemplo, al apuntar acc(2) a /sys/power/resume. En el punto donde ocurre la escritura en este archivo, la tarea que realiza la llamada ya ha salido y ha llamado a exit_fs(). Por lo tanto, una búsqueda activará una desreferencia NULL al acceder a current->fs. Reorganice el código para que la escritura final ocurra desde workqueue pero con las credenciales del llamador. Esto preserva el (extraño) modelo de permisos y casi no tiene riesgo de regresión. Sin embargo, esta API debería dejar de existir.
References
  • () https://git.kernel.org/stable/c/5d5b936cfa4b0d5670ca7420ef165a074bc008eb -
  • () https://git.kernel.org/stable/c/8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735e -
  • () https://git.kernel.org/stable/c/b03782ae707cc45e65242c7cddd8e28f1c22cde5 -

12 Mar 2025, 10:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-03-12 10:15

Updated : 2025-03-13 16:28

NVD link : CVE-2025-21846

Mitre link : CVE-2025-21846

CVE.ORG link : CVE-2025-21846

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-476

NULL Pointer Dereference