CVE-2024-42237

What it actually does

The length check for firmware block payloads in cs_dsp_load() and cs_dsp_coeff_load() occurs after the length field has already been used, allowing an out-of-bounds read or kernel crash when a malicious payload claims more bytes than remain in the buffer.

Why it matters to the business

Systems may experience unexpected crashes or instability when processing untrusted or malformed firmware files, increasing downtime risk for devices relying on the affected kernel code; low exploit likelihood but requires prompt patching due to kernel exposure.

How an attack unfolds

An attacker with local access supplies a crafted firmware image containing a block whose declared payload length exceeds remaining buffer bytes; the vulnerable code paths dereference or copy using this unchecked length before the late validation, resulting in a kernel fault.

How to fix it

Upgrade the Linux kernel to a version containing commit df0cc57e057f18e44dac8e6c18aba47ab53202f9 or later; for AlmaLinux 8 systems using lldpad, update to 1.0.1-16.git036e314.el8 or newer; rebuild and reboot with the patched kernel.

How to confirm the fix worked

Confirm the running kernel contains df0cc57e057f18e44dac8e6c18aba47ab53202f9 or equivalent backport; test firmware loading with boundary-case payloads that previously triggered the late check; monitor for absence of crashes on valid and invalid firmware inputs.

Typical attack path

1. Obtain local user or process execution context on the target system
2. Prepare a firmware file with an oversized block payload length field
3. Invoke cs_dsp_load or cs_dsp_coeff_load with the malformed firmware
4. Trigger kernel processing that uses the length before the bounds check
5. Cause denial-of-service via crash or memory corruption

How to detect it

Review kernel logs for oops or panic entries near cs_dsp_load or cs_dsp_coeff_load; look for firmware loading operations immediately preceding crashes; no widespread in-the-wild indicators reported.

What your security team should do

• Prioritize kernel updates on all systems exposing cs_dsp firmware loading paths
• Apply the AlmaLinux lldpad package update where applicable
• Restrict unprivileged local users from loading arbitrary firmware images until patched
• Monitor kernel update channels for backports to older stable releases