Subject: CVE-2024-43896: ASoC: cs-amp-lib: Fix NULL pointer crash if efi.get_variable is NULL

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

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

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

ASoC: cs-amp-lib: Fix NULL pointer crash if efi.get_variable is NULL

Call efi_rt_services_supported() to check that efi.get_variable exists
before calling it.

The Linux kernel CVE team has assigned CVE-2024-43896 to this issue.

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

	Issue introduced in 6.9 with commit 1cad8725f2b9 and fixed in 6.10.5 with commit 5b6baaa7cbd7
	Issue introduced in 6.9 with commit 1cad8725f2b9 and fixed in 6.11 with commit dc268085e499

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-2024-43896
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/codecs/cs-amp-lib.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/5b6baaa7cbd77ff980516bad38bbc5a648bb5158
	https://git.kernel.org/stable/c/dc268085e499666b9f4f0fcb4c5a94e1c0b193b3