Ok. With CONFIG_LOAD_UEFI_KEYS=n, can you run:
cat /sys/firmware/efi/efivars/db-d719b2cb-3d3a-4596-a3bc-dad00e67656f
and see whether it generates the same failure? If so then my (handwavy) guess is that something's going wrong with a firmware codepath for the d719b2cb-3d3a-4596-a3bc-dad00e67656f GUID. Someone could potentially then figure out whether the same happens under Windows, but the easiest thing is probably to just return a failure on Apple hardware when someone tries to access anything with that GUID.
Surprisingly it didn’t cause a crash. The logs are at https://gist.githubusercontent.com/AdityaGarg8/8e820c2724a65fb4bbb5deae2b358...
I also tried cat /sys/firmware/efi/efivars/MokIgnoreDB-605dab50-e046-4300-abb6-3dd810dd8b23, but it doesn’t exist
aditya@MacBook:~$ cat /sys/firmware/efi/efivars/MokIgnoreDB-605dab50-e046-4300-abb6-3dd810dd8b23 cat: /sys/firmware/efi/efivars/MokIgnoreDB-605dab50-e046-4300-abb6-3dd810dd8b23: No such file or directory