Subject: CVE-2024-49909: drm/amd/display: Add NULL check for function pointer in dcn32_set_output_transfer_func

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

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

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

drm/amd/display: Add NULL check for function pointer in dcn32_set_output_transfer_func

This commit adds a null check for the set_output_gamma function pointer
in the dcn32_set_output_transfer_func function. Previously,
set_output_gamma was being checked for null, but then it was being
dereferenced without any null check. This could lead to a null pointer
dereference if set_output_gamma is null.

To fix this, we now ensure that set_output_gamma is not null before
dereferencing it. We do this by adding a null check for set_output_gamma
before the call to set_output_gamma.

The Linux kernel CVE team has assigned CVE-2024-49909 to this issue.

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

	Fixed in 6.10.14 with commit 496486950c3d
	Fixed in 6.11.3 with commit 5298270bdabe
	Fixed in 6.12-rc1 with commit 28574b08c70e

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-2024-49909
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:
	drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.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/496486950c3d2aebf46a3be300296ac091da7a2d
	https://git.kernel.org/stable/c/5298270bdabe97be5b8236e544c9e936415fe1f2
	https://git.kernel.org/stable/c/28574b08c70e56d34d6f6379326a860b96749051