Subject: CVE-2024-42088: ASoC: mediatek: mt8195: Add platform entry for ETDM1_OUT_BE dai link

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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.

The Linux kernel CVE team has assigned CVE-2024-42088 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 6.8 with commit e70b8dd26711 and fixed in 6.9.8 with commit 42b9ab7a4d7e
	Issue introduced in 6.8 with commit e70b8dd26711 and fixed in 6.10 with commit 282a4482e198

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-42088
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	sound/soc/mediatek/mt8195/mt8195-mt6359.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/42b9ab7a4d7e6c5efd71847541e4fcc213585aad
	https://git.kernel.org/stable/c/282a4482e198e03781c152c88aac8aa382ef9a55