CVE-2024-50287

What it actually does

Division by zero in tpg_precalculate_line() when scaled_width equals zero during V4L2 test pattern generator buffer rescaling, leading to potential kernel panic or undefined behavior.

Why it matters to the business

Risk of system instability or crashes during media/video processing workloads on affected Linux kernels, potentially disrupting services that rely on V4L2 devices; low prevalence reduces overall exposure.

How an attack unfolds

An attacker with local access crafts input that triggers scaled_width of zero in the V4L2 TPG path, causing the unhandled division and kernel fault; no public exploitation observed despite listed threat actor campaigns targeting similar kernel issues.

How to fix it

Update to kernel versions containing the fix that adds WARN_ON_ONCE() check and early return; apply available stable updates for affected distributions.

How to confirm the fix worked

Confirm kernel source contains the tpg_precalculate_line() guard; test with zero scaled_width input to ensure no crash occurs; monitor for WARN_ON_ONCE() logs.

Typical attack path

1. Obtain local code execution or access on target system
2. Load or interact with V4L2 TPG module to reach tpg_precalculate_line()
3. Supply parameters resulting in scaled_width == 0
4. Trigger division by zero leading to kernel crash or DoS

How to detect it

Search kernel logs for division-by-zero faults or WARN_ON_ONCE() messages referencing tpg_precalculate_line(); inspect V4L2 device usage in media workloads for anomalous inputs.

What your security team should do

• Prioritize kernel updates on systems using V4L2 media subsystems
• Review logs for any prior WARN_ON_ONCE() or division errors in v4l2-tpg
• Limit untrusted local access to media devices until patched