Use After Free in Linux
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.
Vulnerability class: Use-After-Free
EPSS: 0.002 (12.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Linux — versions 9ec03d7f1ed394897891319a4dda75f52c5d292d, 5.12, 0
- Linux Linux_kernel — versions 5.16
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2021-47533?
- CVE-2021-47533 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2024-05-24.
- How severe is CVE-2021-47533?
- High severity. CVSS v3 base score is 7.8 out of 10.