CVE-2023-53851: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53851 is a use-after-free vulnerability in the Linux kernel's DRM/MSM DisplayPort (DP) subsystem, specifically in the drm/msm/dp driver. The flaw arises from improper lifecycle management of auxiliary (aux) bus devices relative to the DP controller teardown sequence. It affects Linux kernel versions from commit 2b57f726611e up to the fixes introduced in kernel versions 6.3.13, 6.4.4, and 6.5. The vulnerability was published on December 9, 2025, and has an estimated CVSS severity of Medium with an EPSS score of approximately 0.017% (Feedly, Red Hat).

The root cause is a use-after-free condition (CWE-416) in the Linux kernel's drm/msm/dp driver. Device resources (devres) for the aux bus were tied to the DPU's drm_dev->dev struct device rather than the DP controller's own device, meaning the aux bus could be depopulated after the DP controller was already torn down. When an EDP panel subsequently attempted to read EDID information via the aux bus, it accessed already-freed DP resources, triggering a KASAN-reported use-after-free fault. Observable symptoms include EDID hexdumps filled with zeros in kernel logs and occasional KASAN faults. The fix explicitly depopulates the aux bus in both the error path and the component unbind path to ensure proper ordering (Feedly, Patchwork).

Successful triggering of this vulnerability can cause kernel memory corruption via a use-after-free, potentially leading to system instability, kernel panics, or denial of service on affected devices. In more severe scenarios, use-after-free vulnerabilities in kernel drivers can theoretically be leveraged for local privilege escalation, though no such exploitation has been demonstrated for this specific CVE. The impact is primarily limited to systems using Qualcomm MSM/Snapdragon SoCs with embedded DisplayPort (eDP) panels, such as certain ARM-based laptops and mobile devices running affected Linux kernel versions (Feedly).

The fix has been backported to stable Linux kernel versions 6.3.13, 6.4.4, and 6.5 via commits e09ed06938807cb113cddd0708ed74bd8cdaff33, 2fde37445807e6e6d7981402d0bf1be0e5d81291, and a7bfb2ad2184a1fba78be35209b6019aa8cc8d4d respectively. Users and administrators should update to a patched kernel version. Distributions such as SUSE have also issued kernel security advisories addressing this CVE. No configuration-based workaround is available; upgrading the kernel is the recommended remediation (Red Hat, Linux Security).