CVE-2023-53851

What it actually does

Use-after-free in the Linux kernel DRM MSM DP driver when aux bus devices are not properly depopulated during probe deferral or component unbind, allowing panel EDID reads to access freed DP resources.

Why it matters to the business

Kernel crashes, memory corruption, or potential privilege escalation on affected Linux systems with MSM display hardware; low exploitability reduces immediate risk but still requires patching on servers and endpoints using the affected display stack.

How an attack unfolds

An attacker with local access triggers repeated probe deferrals or DP controller teardown on systems with eDP panels, causing the aux device to outlive the controller; subsequent EDID reads then dereference freed memory, potentially leading to KASAN faults or exploitable UAF.

How to fix it

Update the Linux kernel to commit e09ed06938807cb113cddd0708ed74bd8cdaff33 or later stable releases that explicitly depopulate the aux bus in error and unbind paths; for mysql-client (Bitnami) upgrade to 10.6.21 or newer.

How to confirm the fix worked

Verify the presence of the fix commit in the running kernel source, confirm no EDID-hexdump-of-zeros warnings appear during DP probe, and test panel initialization under probe-deferral conditions.

Typical attack path

1. Trigger DP controller probe deferral or unbind path
2. Allow aux bus device to remain while DP resources are freed
3. Initiate EDID read from panel device
4. Access freed DP structures resulting in use-after-free

How to detect it

Search kernel logs for repeated EDID-hexdump full of zeros, KASAN use-after-free reports involving drm/msm/dp or aux bus during probe deferral or unbind; inspect dmesg and journalctl for panel device recreation attempts.

What your security team should do

• Prioritize kernel updates on systems with MSM/Qualcomm display hardware
• Monitor for KASAN reports or EDID read failures in logs
• Apply the specific fixed commit e09ed06938807cb113cddd0708ed74bd8cdaff33 where backports are needed