CVE-2024-56572

What it actually does

Memory leak in allocate_buffers_internal() where a buffer allocated in a loop is not freed on the allegro_alloc_buffer failure path, allowing gradual accumulation of unreleased kernel memory.

Why it matters to the business

Systems running affected kernel builds may experience slow memory exhaustion, leading to degraded performance, out-of-memory conditions, or eventual crashes during prolonged media processing workloads.

How an attack unfolds

An attacker would need to trigger repeated allocation failures in the allegro-dvt buffer allocation path under specific error conditions; the leak itself is passive and does not provide direct code execution or privilege escalation.

How to fix it

Update the Linux kernel to the fixed commit cf642904be39ae0d441dbdfa8f485e0a46260be4 or later stable releases containing the fix that releases the buffer on allegro_alloc_buffer failure.

How to confirm the fix worked

Verify the presence of the patch in the running kernel source or confirm the kernel version/build includes cf642904be39ae0d441dbdfa8f485e0a46260be4; inspect allocate_buffers_internal for proper buffer release on error.

Typical attack path

1. Identify a workload or input that exercises the allegro-dvt allocate_buffers_internal path
2. Induce allocation failures (e.g., via resource pressure) to enter the error path
3. Repeat to accumulate leaked buffers over time

How to detect it

Review kernel logs for repeated allocation failures in the allegro-dvt driver; inspect memory usage trends on systems with the affected driver enabled; no specific runtime artifacts indicate prior exploitation of this leak.

What your security team should do

• Prioritize patching kernel packages on systems using the allegro-dvt driver
• Monitor for unusual memory growth in media-related processes after applying the fix
• Review downstream kernel distributions for backported fixes given the driver's limited prevalence