CVE-2026-68346: ALSA: hda: cs35l41: validate and free ACPI mute object

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

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

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

ALSA: hda: cs35l41: validate and free ACPI mute object

cs35l41_get_acpi_mute_state() evaluates a _DSM method to get the ACPI
mute state and reads the first byte from the returned object.

However, the returned ACPI object is owned by the caller and is never
freed after use, so each successful query leaks the _DSM result object.

The code also assumes that the returned object is a buffer with at least
one byte. A malformed firmware response can return a different object
type or an empty buffer, and the direct ret->buffer.pointer dereference
can then access an invalid pointer.

Use the typed _DSM helper, validate that the returned buffer contains at
least one byte, and free the ACPI object after reading it.

The Linux kernel CVE team has assigned CVE-2026-68346 to this issue.


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

	Issue introduced in 6.7 with commit 447106e92a0c86c332d40710436f38f64c322cd6 and fixed in 6.12.101 with commit 7fea0c89ed39a13d9a31163a74f8c62de30a4ffc
	Issue introduced in 6.7 with commit 447106e92a0c86c332d40710436f38f64c322cd6 and fixed in 6.18.42 with commit 08433c71f15984ddd5f5a307cf3f0aa9b84583aa
	Issue introduced in 6.7 with commit 447106e92a0c86c332d40710436f38f64c322cd6 and fixed in 7.1.6 with commit d5dfdf43259ad9d054052012095b1630e7366dcf
	Issue introduced in 6.7 with commit 447106e92a0c86c332d40710436f38f64c322cd6 and fixed in 7.2-rc5 with commit 3b597d24dc0455ae926f1053f97c2725038fc3cd

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-2026-68346
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/hda/codecs/side-codecs/cs35l41_hda.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/7fea0c89ed39a13d9a31163a74f8c62de30a4ffc
	https://git.kernel.org/stable/c/08433c71f15984ddd5f5a307cf3f0aa9b84583aa
	https://git.kernel.org/stable/c/d5dfdf43259ad9d054052012095b1630e7366dcf
	https://git.kernel.org/stable/c/3b597d24dc0455ae926f1053f97c2725038fc3cd