Meanwhile, it seems that this issue was already addressed in: https://lore.kernel.org/all/20211215021348.8766-1-kernelfans@xxxxxxxxx/ ..which has now been pulled in, and sent to stable@ for 5.15. I somehow missed that message, and sent my change in a few weeks later. The fix to just reserve the ranges does seem a bit cleaner overall, but this will do fine. Thanks! - Frank