Double fault crash on Linux-5.1.21

[Angel Shtilianov]

Hi there,
I have a very strange crash with kernel 5.1.21
This has happened several times with kernel 5.x, but this time I have
collected a usable crash dump.
The process in question seems to be dying - in its task_struct it has set:
  exit_signal = 17,
  pdeath_signal = 0,
Any ideas how to debug it are highly appreciated. Please, help.
Here is the complete crash backtrace:
https://pastebin.com/FF3rn1CZ

--
Best regards,
Angel Shtilianov