CVE-2024-43829: drm/qxl: Add check for drm_cvt_mode

CVE-2024-43829: drm/qxl: Add check for drm_cvt_mode

[Greg Kroah-Hartman]

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

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

drm/qxl: Add check for drm_cvt_mode

Add check for the return value of drm_cvt_mode() and return the error if
it fails in order to avoid NULL pointer dereference.

The Linux kernel CVE team has assigned CVE-2024-43829 to this issue.


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

	Issue introduced in 5.1 with commit 1b043677d4be and fixed in 6.1.103 with commit f28b353c0c6c
	Issue introduced in 5.1 with commit 1b043677d4be and fixed in 6.6.44 with commit 4b1f303bdece
	Issue introduced in 5.1 with commit 1b043677d4be and fixed in 6.10.3 with commit d4c57354a06c
	Issue introduced in 5.1 with commit 1b043677d4be and fixed in 6.11-rc1 with commit 7bd09a2db0f6

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-2024-43829
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/qxl/qxl_display.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/f28b353c0c6c7831a70ccca881bf2db5e6785cdd
	https://git.kernel.org/stable/c/4b1f303bdeceac049e56e4b20eb5280bd9e02f4f
	https://git.kernel.org/stable/c/d4c57354a06cb4a77998ff8aa40af89eee30e07b
	https://git.kernel.org/stable/c/7bd09a2db0f617377027a2bb0b9179e6959edff3