App - Système

I am currently stuck in the ELF x64 - Buggy VM problem.

Something that is not new to anyone doing this kind of problem is trying :
Disassembling the code in GDB and decompiling it with Ghidra.

I slightly understood the Ghidra decompiled code, but it was not enough to give me further clues.

Anyone up to discuss this challenge ?

Bonus precise question :
Why entering a text file to this code makes it block and entering a bytecode( a c compiled code for example) the code runs until the end ?