Notes to myself. Disable ASLR:
```
echo 0 > /proc/sys/kernel/randomize_va_space
```
Compile like this:
```
gcc -fno-stack-protector -z execstack vulnerable.c -o vulnerable
```
Reference tutorial: https://www.ired.team/offensive-security/code-injection-process-injection/binary-exploitation/64-bit-stack-based-buffer-overflow

Possibly relevant issues:
* radareorg/radare2#7819
* radareorg/radare2#5081