CVE-2024-50173

What it actually does

Access to uninitialized variable in tick_ctx_cleanup() because the group variable references a previously iterated list_head instead of a valid group object, allowing memory corruption via incorrect ptdev retrieval.

Why it matters to the business

Kernel-level memory corruption risk in graphics drivers can cause system crashes, instability, or potential privilege escalation on affected Linux systems; low urgency given zero EPSS trend, no KEV status, and no ransomware use despite listed threat actor campaigns.

How an attack unfolds

Attackers trigger the scheduler cleanup path in the Panthor DRM driver, relying on the erroneous group pointer from prior list iteration to access uninitialized data, enabling out-of-bounds read/write or corruption; listed espionage and financially motivated actors have targeted similar Linux kernel uninitialized resource and out-of-bounds issues in 2024 campaigns.

How to fix it

Update the Linux kernel so that ptdev is obtained from the scheduler in tick_ctx_cleanup(); apply all available fixes for affected packages.

How to confirm the fix worked

Confirm the corrected code path retrieves ptdev from the scheduler and verify no list_head misuse in tick_ctx_cleanup(); test graphics scheduler cleanup under load.

Typical attack path

1. Locate systems running vulnerable Linux kernel with Panthor DRM driver
2. Trigger tick_ctx_cleanup via crafted graphics or scheduler operations
3. Exploit uninitialized group variable to read or corrupt memory
4. Escalate to kernel-level access or cause denial of service

How to detect it

Inspect kernel logs and scheduler traces for tick_ctx_cleanup errors or list iteration anomalies; correlate with threat actor activity around Linux kernel out-of-bounds and uninitialized resource flaws.

What your security team should do

• Prioritize kernel updates on systems using Panthor DRM
• Monitor for similar uninitialized variable patterns in other DRM drivers
• Review logs for scheduler cleanup anomalies
• Apply patches within standard maintenance windows given low EPSS