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

drm/amd/display: Fix mismatched unlock for DMUB HW lock in HWSS fast path

[Why]
The evaluation for whether we need to use the DMUB HW lock isn't the
same as whether we need to unlock which results in a hang when the
fast path is used for ASIC without FAMS support.

[How]
Store a flag that indicates whether we should use the lock and use
that same flag to specify whether unlocking is needed.