Subject: CVE-2024-46712: drm/vmwgfx: Disable coherent dumb buffers without 3d

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

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

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

drm/vmwgfx: Disable coherent dumb buffers without 3d

Coherent surfaces make only sense if the host renders to them using
accelerated apis. Without 3d the entire content of dumb buffers stays
in the guest making all of the extra work they're doing to synchronize
between guest and host useless.

Configurations without 3d also tend to run with very low graphics
memory limits. The pinned console fb, mob cursors and graphical login
manager tend to run out of 16MB graphics memory that those guests use.

Fix it by making sure the coherent dumb buffers are only used on
configs with 3d enabled.

The Linux kernel CVE team has assigned CVE-2024-46712 to this issue.

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

	Issue introduced in 6.10.4 with commit af6441e6f3d4 and fixed in 6.10.8 with commit c45558414b8f

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-2024-46712
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/vmwgfx/vmwgfx_surface.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/c45558414b8f2e0b9dc34eb8f9d4e8359b887681
	https://git.kernel.org/stable/c/e9fd436bb8fb9b9d31fdf07bbcdba6d30290c5e4