CVE-2024-46745

What it actually does

The flaw permits user-space requests via the uinput interface to specify an excessive number of slots, causing input_mt_init_slots to attempt large memory allocations that may fail or impose heavy system burden before rejection.

Why it matters to the business

Local processes can trigger resource exhaustion or allocation failures on Linux systems, leading to performance degradation or instability in multi-user, containerized, or shared environments.

How an attack unfolds

An attacker with local access submits crafted uinput device setup requests containing an unreasonably high slot count, which the kernel processes before properly bounding, resulting in attempted large allocations.

How to fix it

Upgrade the Linux kernel to a version containing commit 9c6d189f0c1c59ba9a32326ec82a0b367a3cd47b, which caps allowed slots at 100.

How to confirm the fix worked

Confirm the running kernel includes the referenced commit; attempt to create a uinput device with over 100 slots and verify immediate rejection without large allocation attempts.

Typical attack path

1. Gain local user access on an affected Linux system
2. Open /dev/uinput and issue device creation ioctls specifying more than 100 slots
3. Trigger input_mt_init_slots allocation path

How to detect it

Inspect kernel logs for uinput-related memory allocation failures or warnings about excessive slots; monitor processes making frequent or large uinput device setup calls.

What your security team should do

• Apply the kernel fix containing commit 9c6d189f0c1c59ba9a32326ec82a0b367a3cd47b on all affected systems
• Restrict uinput access to trusted processes only
• Review logs for repeated uinput slot allocation failures