root_exec kernel module

A kernel module (for use in CTFs) that will execute arbitrary commands

1. use make to build a root_exec.ko
2. then sudo insmod root_exec.ko to install the module (obviously you need permissions to do this - ctf had this as an allowable sudoers command)
3. finally, the command will be run when you cat /proc/root_exec

By default, the root_exec.c module will copy /bin/sh to tmp, and make it suid so you can use sh -p to jump to root.

Credits:

• deepseek (after a long battle with various hallucinations and dire warnings) helped me write this
• it was built for the challenge 'Avengers Hub' in TryHackMe's Hackfinity CTF, March 2025