CVE-2021-47534 drm/vc4: kms: Add missing drm_crtc_commit_put

What is CVE-2021-47534?

CVE-2021-47534 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

drm/vc4: kms: Add missing drm_crtc_commit_put

Commit 9ec03d7f1ed3 ("drm/vc4: kms: Wait on previous FIFO users before a commit") introduced a global state for the HVS, with each FIFO storing the current CRTC commit so that we can properly synchronize commits.

However, the refcounting was off and we thus ended up leaking the drm_crtc_commit structure every commit. Add a drm_crtc_commit_put to prevent the leakage.

Which versions are affected by CVE-2021-47534?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47534?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-47534 being exploited?

There is no known exploitation of CVE-2021-47534 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• How this page is made

Also known as DEBIAN-CVE-2021-47534, UBUNTU-CVE-2021-47534.