Subject: CVE-2024-37026: drm/xe: Only use reserved BCS instances for usm migrate exec queue

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

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

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

drm/xe: Only use reserved BCS instances for usm migrate exec queue

The GuC context scheduling queue is 2 entires deep, thus it is possible
for a migration job to be stuck behind a fault if migration exec queue
shares engines with user jobs. This can deadlock as the migrate exec
queue is required to service page faults. Avoid deadlock by only using
reserved BCS instances for usm migrate exec queue.

(cherry picked from commit 04f4a70a183a688a60fe3882d6e4236ea02cfc67)

The Linux kernel CVE team has assigned CVE-2024-37026 to this issue.

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

	Issue introduced in 6.8 with commit a043fbab7af5 and fixed in 6.9.4 with commit 92deed4a9bfd
	Issue introduced in 6.8 with commit a043fbab7af5 and fixed in 6.10 with commit c8ea2c31f5ea

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-2024-37026
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/xe/xe_migrate.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/92deed4a9bfd9ef187764225bba530116c49e15c
	https://git.kernel.org/stable/c/c8ea2c31f5ea437199b239d76ad5db27343edb0c