CVE-2023-53851 drm/msm/dp: Drop aux devices together with DP controller

What is CVE-2023-53851?

CVE-2023-53851 is a high-severity use after free vulnerability in Linux, published on 9 Dec 2025. 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/msm/dp: Drop aux devices together with DP controller

Using devres to depopulate the aux bus made sure that upon a probe deferral the EDP panel device would be destroyed and recreated upon next attempt.

But the struct device which the devres is tied to is the DPUs (drm_dev->dev), which may be happen after the DP controller is torn down.

Indications of this can be seen in the commonly seen EDID-hexdump full of zeros in the log, or the occasional/rare KASAN fault where the panel's attempt to read the EDID information causes a use after free on DP resources.

It's tempting to move the devres to the DP controller's struct device, but the resources used by the device(s) on the aux bus are explicitly torn down in the error path. The KASAN-reported use-after-free also remains, as the DP aux "module" explicitly frees its devres-allocated memory in this code path.

As such, explicitly depopulate the aux bus in the error path, and in the component unbind path, to avoid these issues.

Patchwork: https://patchwork.freedesktop.org/patch/542163/

Which versions are affected by CVE-2023-53851?

How do I fix CVE-2023-53851?

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-2023-53851 being exploited?

There is no known exploitation of CVE-2023-53851 in the wild and no public exploit code.

Sources

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

Also known as BELL-CVE-2023-53851, DEBIAN-CVE-2023-53851, GHSA-wxfw-x294-cg88, ROOT-OS-DEBIAN-12-CVE-2023-53851, UBUNTU-CVE-2023-53851.