CVE-2024-46810

What it actually does

NULL pointer dereference in the tc358767 DRM bridge driver when drm_kms_helper_hotplug_event() is called before the connector is fully initialized via IRQ-driven HPD signaling.

Why it matters to the business

Systems using affected Linux kernel versions with tc358767 hardware may experience unexpected crashes or display instability, potentially disrupting operations on servers, workstations, or embedded devices with this graphics bridge; low urgency as not known to be exploited in the wild.

How an attack unfolds

An attacker with local access or ability to influence hardware IRQ timing triggers the uninitialized connector state, causing the kernel to dereference a NULL pointer during hotplug event signaling and resulting in a crash; listed threat actors have not been tied to this specific flaw.

How to fix it

Upgrade the Linux kernel to commit adc5674c23b8191e596ed0dbaa9600265ac896a8 or a later stable version containing the fix; rebuild and deploy updated kernels across affected systems.

How to confirm the fix worked

Verify the running kernel includes commit adc5674c23b8191e596ed0dbaa9600265ac896a8, reproduce HPD events in a test environment, and confirm no NULL dereference occurs in drm/bridge/tc358767.c.

Typical attack path

1. Obtain local access or control hardware events affecting the tc358767 bridge
2. Force or wait for IRQ signaling of HPD before full connector initialization
3. Trigger drm_kms_helper_hotplug_event() on uninitialized state
4. Induce NULL pointer dereference leading to kernel panic

How to detect it

Review kernel ring buffer and syslog for NULL pointer dereference panics referencing drm_kms_helper_hotplug_event or tc358767; correlate with recent hardware hotplug activity.

What your security team should do

• Apply the kernel patch containing adc5674c23b8191e596ed0dbaa9600265ac896a8 as soon as possible on all systems using tc358767 hardware
• Monitor kernel logs for oops/panics involving drm_kms_helper_hotplug_event
• Test display hotplug functionality post-upgrade in staging environments
• Prioritize updates on internet-facing or high-availability systems