Comment 27 for bug 1830951

@cypressyew, I cannot have proof that the same issue occurred with v5.2 rc2 from your link, as the kernel does not respond to earlyprintk=efi, but it died pretty much the same way, and no logs were produced.
As I mentioned earlier, the fix in efi.c is a clear indication of a bug in the kernel code. If that isn't sufficient, I'm not sure what is.

The same bug exists in the latest kernel source.
https://git.launchpad.net/~ubuntu-kernel-test/ubuntu/+source/linux/+git/mainline-crack/tree/drivers/firmware/efi/efi.c#n258

That being said, if you could provide me a kernel build that will have proper logging I could capture, then I can try again. But please, please, to save us some time, first take a quick look at the source, it isn't too hard to see if it is a legitimate bug.