CVE-2024-46793

What it actually does

The flaw is an out-of-bounds array reference and potential NULL pointer dereference in ASoC Intel BYT/CHT board drivers when dummy codec DAI link components expand to a zero-sized array; code that assumes dais[i].codecs is valid and checks only .name can read unmapped memory and crash.

Why it matters to the business

Affected Linux systems can suffer kernel panics or sudden reboots during audio device initialization, causing loss of service and unplanned downtime on desktops, laptops, and embedded devices that use these Intel audio configurations.

How an attack unfolds

An attacker with local access or the ability to trigger module loading causes the snd_soc_sst_bytcr_* driver to probe; the zero-length dummy codec array leads the existing name check to dereference an adjacent variable, producing a page fault when that memory is not NULL.

How to fix it

Upgrade the Linux kernel to a version that includes commit 85cda5b040bda9c577b34eb72d5b2e5b7e31985c (or later equivalent) so that the driver checks dais.num_codecs != 0 before accessing any codec fields.

How to confirm the fix worked

Confirm the source tree contains the num_codecs guard, rebuild, boot the new kernel, and verify that audio modules initialize without page-fault crashes; inspect dmesg for absence of the prior strcmp/page-fault signature.

Typical attack path

1. Obtain local execution or trigger audio subsystem initialization
2. Load an affected Intel SST BYT/CHT sound card module
3. Reach platform_probe and the dais codec name check
4. Trigger strcmp on an invalid address resulting in BUG page fault

How to detect it

Search kernel logs and crash dumps for page-fault BUG reports containing strcmp, platform_probe, and references to snd_soc_sst_bytcr_wm5102 or similar BYT/CHT modules; correlate with module load events around the timestamp of the fault.

• BUG: unable to handle page fault for address
• snd_soc_sst_bytcr_wm5102
• strcmp+0x18/0x40
• platform_probe+0x40/0xa0

What your security team should do

• Prioritize kernel package updates on all affected Intel audio platforms
• Reboot systems after applying the fixed kernel
• Add kernel oops and page-fault alerts to existing monitoring for early detection of residual instances