Vulnerability · Published May 24, 2024 · Assigned by Linux

CVE-2021-47533drm/vc4: kms: Clear the HVS FIFO commit pointer once done

High 7.8

In plain English

A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.2%top 87.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.15.15-1DEBIAN-CVE-2021-47533
Debian:13linux5.15.15-1DEBIAN-CVE-2021-47533
Debian:14linux5.15.15-1DEBIAN-CVE-2021-47533
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2021-47533
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2021-47533

Affected products (as reported)

VendorProductVersions
Linux Linux 9ec03d7f1ed394897891319a4dda75f52c5d292d – before 2931db9a5ed219546cf2ae0546698faf78281b899ec03d7f1ed394897891319a4dda75f52c5d292d – before d134c5ff71c7f2320fc7997f2fbbdedf0c76889a
Linux Linux 5.12

References