CVE-2021-47063 drm: bridge/panel: Cleanup connector on bridge detach

What is CVE-2021-47063?

CVE-2021-47063 is a high-severity use after free vulnerability in Linux kernel, published on 29 Feb 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: bridge/panel: Cleanup connector on bridge detach

If we don't call drm_connector_cleanup() manually in panel_bridge_detach(), the connector will be cleaned up with the other DRM objects in the call to drm_mode_config_cleanup(). However, since our drm_connector is devm-allocated, by the time drm_mode_config_cleanup() will be called, our connector will be long gone. Therefore, the connector must be cleaned up when the bridge is detached to avoid use-after-free conditions.

v2: Cleanup connector only if it was created

v3: Add FIXME

v4: (Use connector->dev) directly in if() block

Weakness: CWE-416

Which versions are affected by CVE-2021-47063?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47063?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2021-47063 being exploited?

There is no known exploitation of CVE-2021-47063 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
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-47063, GHSA-g6q3-47r5-q8fc, UBUNTU-CVE-2021-47063.