Subject: CVE-2024-42117: drm/amd/display: ASSERT when failing to find index by plane/stream id

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

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

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

drm/amd/display: ASSERT when failing to find index by plane/stream id

[WHY]
find_disp_cfg_idx_by_plane_id and find_disp_cfg_idx_by_stream_id returns
an array index and they return -1 when not found; however, -1 is not a
valid index number.

[HOW]
When this happens, call ASSERT(), and return a positive number (which is
fewer than callers' array size) instead.

This fixes 4 OVERRUN and 2 NEGATIVE_RETURNS issues reported by Coverity.

The Linux kernel CVE team has assigned CVE-2024-42117 to this issue.

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

	Fixed in 6.9.9 with commit a9c047a5cf31
	Fixed in 6.10 with commit 01eb50e53c1c

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-2024-42117
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/dml2/dml2_dc_resource_mgmt.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/a9c047a5cf3135b8b66bd28fbe2c698b9cace0b3
	https://git.kernel.org/stable/c/01eb50e53c1ce505bf449348d433181310288765