Subject: CVE-2024-42121: drm/amd/display: Check index msg_id before read or write

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

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

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

drm/amd/display: Check index msg_id before read or write

[WHAT]
msg_id is used as an array index and it cannot be a negative value, and
therefore cannot be equal to MOD_HDCP_MESSAGE_ID_INVALID (-1).

[HOW]
Check whether msg_id is valid before reading and setting.

This fixes 4 OVERRUN issues reported by Coverity.

The Linux kernel CVE team has assigned CVE-2024-42121 to this issue.

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

	Fixed in 5.10.222 with commit b5b8837d066c
	Fixed in 5.15.163 with commit fbb0701af973
	Fixed in 6.1.98 with commit ae91ffbc8b8d
	Fixed in 6.6.39 with commit 9933eca6ada0
	Fixed in 6.9.9 with commit a31ea49dc806
	Fixed in 6.10 with commit 59d99deb330a

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-2024-42121
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/modules/hdcp/hdcp_ddc.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/b5b8837d066cc182ff69fb5629ad32ade5484567
	https://git.kernel.org/stable/c/fbb0701af9734cff13917a4b98b5ee9da2fde48d
	https://git.kernel.org/stable/c/ae91ffbc8b8d942e3e7f188728cad557b7ed5ee4
	https://git.kernel.org/stable/c/9933eca6ada0cd612e19522e7a319bcef464c0eb
	https://git.kernel.org/stable/c/a31ea49dc8064a557565725cf045944307476a6e
	https://git.kernel.org/stable/c/59d99deb330af206a4541db0c4da8f73880fba03