CVE-2021-47533

drm/vc4: kms: Clear the HVS FIFO commit pointer once done

Description

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.

N/A

CVSS

Severity:

EPSS 0.07%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/2931db9a5ed219546cf2ae0546698faf78281b89
https://git.kernel.org/stable/c/d134c5ff71c7f2320fc7997f2fbbdedf0c76889a

Frequently Asked Questions

What is the severity of CVE-2021-47533?: CVE-2021-47533 has not yet been assigned a CVSS score.
How to fix CVE-2021-47533?: To fix CVE-2021-47533, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-47533 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2021-47533 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-47533?: CVE-2021-47533 affects Linux Linux, Linux Linux.

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