CVE-2021-47533

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: kms: Clear the HVS FIFO commit pointer once done Commit 9ec03d7f1ed3 ("drm/vc4: kms: Wait on previous FIFO users before a commit") introduced a wait on the previous commit done on a given HVS FIFO. However, we never cleared that pointer once done. Since drm_crtc_commit_put can free the drm_crtc_commit structure directly if we were the last user, this means that it can lead to a use-after free if we were to duplicate the state, and that stale pointer would even be copied to the new state. Set the pointer to NULL once we're done with the wait so that we don't carry over a pointer to a free'd structure.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*

History

18 Sep 2025, 15:56

Type Values Removed Values Added
First Time Linux
Linux linux Kernel
References () https://git.kernel.org/stable/c/2931db9a5ed219546cf2ae0546698faf78281b89 - () https://git.kernel.org/stable/c/2931db9a5ed219546cf2ae0546698faf78281b89 - Patch
References () https://git.kernel.org/stable/c/d134c5ff71c7f2320fc7997f2fbbdedf0c76889a - () https://git.kernel.org/stable/c/d134c5ff71c7f2320fc7997f2fbbdedf0c76889a - Patch
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*
CWE CWE-416
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

21 Nov 2024, 06:36

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/2931db9a5ed219546cf2ae0546698faf78281b89 - () https://git.kernel.org/stable/c/2931db9a5ed219546cf2ae0546698faf78281b89 -
References () https://git.kernel.org/stable/c/d134c5ff71c7f2320fc7997f2fbbdedf0c76889a - () https://git.kernel.org/stable/c/d134c5ff71c7f2320fc7997f2fbbdedf0c76889a -
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: drm/vc4: kms: borre el puntero de commit FIFO de HVS una vez realizado. El commit 9ec03d7f1ed3 ("drm/vc4: kms: espere a los usuarios FIFO anteriores antes de una confirmación") introdujo una espera en el commit anterior realizada en un HVS FIFO determinado. Sin embargo, nunca borramos ese puntero una vez hecho. Dado que drm_crtc_commit_put puede liberar la estructura drm_crtc_commit directamente si fuéramos el último usuario, esto significa que puede llevar a un use-after free si duplicáramos el estado, y ese puntero obsoleto incluso se copiaría al nuevo estado. Establezca el puntero en NULL una vez que hayamos terminado con la espera para que no transfiramos un puntero a una estructura liberada.

24 May 2024, 15:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-05-24 15:15

Updated : 2025-09-18 15:56


NVD link : CVE-2021-47533

Mitre link : CVE-2021-47533

CVE.ORG link : CVE-2021-47533


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-416

Use After Free