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

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

The MES scheduler ring has no drm scheduler (no_scheduler = true), so it is
skipped by the force-completion loop in amdgpu_device_pre_asic_reset(). It uses
a polling fence whose hw value lives in wb (GTT) memory and survives a MODE1
reset, while fence_drv.sync_seq keeps advancing for every packet.

When the reset is triggered because MES itself stopped responding, the
timed-out packets advance sync_seq past the last hw fence value MES wrote.
After resume the first MES submission polls forever on a seq that is never
written back, failing the resume and wedging the box on a second reset:

  amdgpu: MES ring buffer is full.
  amdgpu: *ERROR* ring gfx_0.0.0 test failed (-110)
  amdgpu: resume of IP block <gfx_v11_0> failed -110
  amdgpu: GPU reset end with ret = -110

Force complete the MES scheduler ring fences together with the scheduler rings
so their hw fence is realigned to sync_seq.

v2: cover all XCCs (one scheduler ring each), not just mes.ring[0].