Yeah, I pointed this out on the mailing list when when microsoft was trying to upstream their dxgkrnl driver: https://lore.kernel.org/all/CADvTj4q_-A9p2UkH975SPPYmSzVAv38...

As have others: https://lore.kernel.org/all/Yh8wEj5wKMRtxaBB@infradead.org/

Looks like the up-streaming has been abandoned as Microsoft has not made a real effort to fix the issues pointed out: https://lore.kernel.org/all/YinPR66ekfKWHR0R@kroah.com/