Subject: CVE-2022-48849: drm/amdgpu: bypass tiling flag check in virtual display case (v2)

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

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

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

drm/amdgpu: bypass tiling flag check in virtual display case (v2)

vkms leverages common amdgpu framebuffer creation, and
also as it does not support FB modifier, there is no need
to check tiling flags when initing framebuffer when virtual
display is enabled.

This can fix below calltrace:

amdgpu 0000:00:08.0: GFX9+ requires FB check based on format modifier
WARNING: CPU: 0 PID: 1023 at drivers/gpu/drm/amd/amdgpu/amdgpu_display.c:1150 amdgpu_display_framebuffer_init+0x8e7/0xb40 [amdgpu]

v2: check adev->enable_virtual_display instead as vkms can be
	enabled in bare metal as well.

The Linux kernel CVE team has assigned CVE-2022-48849 to this issue.

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

	Fixed in 5.15.29 with commit fcd1d79aa943
	Fixed in 5.16.15 with commit cb29021be498
	Fixed in 5.17 with commit e2b993302f40

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-2022-48849
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/amdgpu/amdgpu_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/fcd1d79aa943fff4fbaa0cce1d576995a7960699
	https://git.kernel.org/stable/c/cb29021be49858059138f75d6311a7c35a9379b2
	https://git.kernel.org/stable/c/e2b993302f40c4eb714ecf896dd9e1c5be7d4cd7