CVE-2023-54263

What it actually does

Uninitialized hpd_irq_lock in the nouveau DRM driver for nv50- PIOR DP paths with ANX9805 encoders causes kernel OOPS on hotplug interrupt handling.

Why it matters to the business

Affected Linux systems with specific NVIDIA-based display hardware may suffer sudden kernel crashes leading to downtime; low urgency as no exploitation or ransomware use is known and EPSS remains negligible.

How an attack unfolds

An attacker triggers a display hotplug event on vulnerable hardware, causing the kernel to dereference the uninitialized lock during IRQ handling and panic.

How to fix it

Upgrade Linux kernel to a version containing commit 92d48ce21645267c574268678131cd2b648dad0f or apply the equivalent fix for the drm/nouveau/kms/nv50- initialization path.

How to confirm the fix worked

Verify presence of the lock initialization in nouveau source or confirm kernel version includes the referenced commit; reproduce hotplug events on ANX9805 hardware to confirm stability.

Typical attack path

1. Obtain local or physical access to trigger display connection events
2. Kernel nouveau driver receives HPD IRQ on ANX9805 PIOR DP path
3. Access to uninitialized hpd_irq_lock produces OOPS and system crash

How to detect it

Search system logs and dmesg for nouveau driver entries mentioning nv50, PIOR DP, hpd_irq_lock, or ANX9805 around the time of kernel panics.

• nouveau.*hpd_irq_lock
• ANX9805
• nv50.*PIOR DP
• Unable to handle kernel paging request.*nouveau

What your security team should do

• Apply fixed kernel versions containing commit 92d48ce21645267c574268678131cd2b648dad0f
• Audit systems for presence of ANX9805 DP encoders and prioritize patching accordingly
• Monitor kernel logs for nouveau-related OOPS until upgrades are complete