CVE-2022-50866

What it actually does

A null pointer dereference occurs in the filter() function when kasprintf() fails to allocate memory and returns NULL, which is then passed to strcmp() without validation.

Why it matters to the business

Systems may experience kernel crashes or instability in audio processing components, leading to denial of service on affected Linux deployments.

How an attack unfolds

An attacker triggers the pxa audio filter path under memory pressure conditions that cause kasprintf allocation failure, resulting in a null pointer access and potential kernel panic.

How to fix it

Apply the fix from commit 3ec75e0ea9550b8f2e531172f2e67ba9d5227ec3 in the Linux kernel stable tree or equivalent updates in affected packages such as livehelperchat/lhc-php-resque.

How to confirm the fix worked

Verify the presence of the null pointer check after kasprintf() in the filter function source code or confirm updated kernel version containing the referenced commit.

Typical attack path

1. Trigger conditions for pxa ASoC filter function
2. Induce memory allocation failure via kasprintf
3. Pass NULL return value to strcmp causing dereference

How to detect it

Inspect kernel logs for null pointer dereference errors or panics involving ASoC pxa filter functions.

What your security team should do

• Update Linux kernel to patched version containing commit 3ec75e0ea9550b8f2e531172f2e67ba9d5227ec3
• Monitor kernel logs for oops or panic messages related to ASoC pxa
• Test audio subsystem functionality after applying updates