CVE-2026-89813: drm/amdgpu: force complete the KIQ ring fences on reset

CVE-2026-89813: drm/amdgpu: force complete the KIQ ring fences on reset

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

drm/amdgpu: force complete the KIQ ring fences on reset

Like the MES scheduler ring, the KIQ ring sets no_scheduler = true and uses a
polling fence, so it is skipped by the force-completion loop in
amdgpu_device_pre_asic_reset(). Its hw fence value lives in wb (GTT) memory and
survives a MODE1 reset while fence_drv.sync_seq keeps advancing, so after a
reset the first KIQ submission can poll forever on a seq that is never written
back.

Force complete the KIQ ring fences too so their hw fence is realigned to
sync_seq.

The Linux kernel CVE team has assigned CVE-2026-89813 to this issue.


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

	Fixed in 7.2.5 with commit bdd6a58743e00ebc6d52b9cdf9aafb4e535e0b71
	Fixed in 7.3-rc1 with commit fd65d1742992361fc2201ecb4e43411e6e417fcb

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-2026-89813
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_device.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/bdd6a58743e00ebc6d52b9cdf9aafb4e535e0b71
	https://git.kernel.org/stable/c/fd65d1742992361fc2201ecb4e43411e6e417fcb