CVE-2024-56685

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

ASoC: mediatek: Check num_codecs is not zero to avoid panic during probe

Following commit 13f58267cda3 ("ASoC: soc.h: don't create dummy

Component via COMP_DUMMY()"), COMP_DUMMY() became an array with zero

length, and only gets populated with the dummy struct after the card is

registered. Since the sound card driver's probe happens before the card

registration, accessing any of the members of a dummy component during

probe will result in undefined behavior.

This can be observed in the mt8188 and mt8195 machine sound drivers. By

omitting a dai link subnode in the sound card's node in the Devicetree,

the default uninitialized dummy codec is used, and when its dai_name

pointer gets passed to strcmp() it results in a null pointer dereference

and a kernel panic.

In addition to that, set_card_codec_info() in the generic helpers file,

mtk-soundcard-driver.c, will populate a dai link with a dummy codec when

a dai link node

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References