CVE-2024-42088: Improper Validation of Array Index

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

ASoC: mediatek: mt8195: Add platform entry for ETDM1_OUT_BE dai link

Commit e70b8dd26711 ("ASoC: mediatek: mt8195: Remove afe-dai component and rework codec link") removed the codec entry for the ETDM1_OUT_BE dai link entirely instead of replacing it with COMP_EMPTY(). This worked by accident as the remaining COMP_EMPTY() platform entry became the codec entry, and the platform entry became completely empty, effectively the same as COMP_DUMMY() since snd_soc_fill_dummy_dai() doesn't do anything for platform entries.

This causes a KASAN out-of-bounds warning in mtk_soundcard_common_probe() in sound/soc/mediatek/common/mtk-soundcard-driver.c:

for_each_card_prelinks(card, i, dai_link) { if (adsp_node && !strncmp(dai_link->name, "AFE_SOF", strlen("AFE_SOF"))) dai_link->platforms->of_node = adsp_node; else if (!dai_link->platforms->name && !dai_link->platforms->of_node) dai_link->platforms->of_node = platform_node; }

where the code expects the platforms array to have space for at least one entry.

Add an COMP_EMPTY() entry so that dai_link->platforms has space.