Kernel: Introduction

Few weeks ago I was invited by one Team to participate as a "guest" during some international CTF competition. Spoiler alert: as I failed strongly during kernel pwn challenges;) (read as: 'mostly all that I tried' ;)) I decided to 'go back' and learn more (to 'try harder' "next time" ;))... Below you'll find few notes from the journey. Here we go...

This time we'll start here:

Just like before - we can use pretty "any" of the resources available online - so I decided to start "from the beginning" and that's how I landed on few interesting 'tutorial pages' (like: 1, 2, 3). After a while I was able to continue with a basic scenario for this exercise:
- prepare a hello_world kernel module
- run it
- find it 'alive'
- unload it.

Easy like that, isn't it? ;) So let's try with the very first example: "hello_world" code. Like this:

After the make command we should be able to use insmod to check our new created basic kernel module (with lsmod).

Ok. Should be enough for the 'quick start'... ;]

See you next time! 

 

Cheers