An Introductory Guide to Techniques for Kernel Exploitation

I’m writing this post because I often hear that kernel exploitation is intimidating or difficult to learn. As a result, I’ve decided to start a series of basic bugs and exercises to get you started!

Prerequisites

• Knowledge of the Linux command line
• Knowing how to read and write basic C may be beneficial
• Being able to debug with the help of a virtual computer or another system
• Able to install the kernel module compilation build requirements
• A basic understanding of the difference between userland and kernelland could be helpful
• Having a basic understanding of assembly can be beneficial for future episodes

For this part, I wrote a simple Linux character device, /dev/shell. This driver will take two arguments, uid and cmd, and it will execute the cmd command as the specified uid. To understand how this driver works, I’ll explain a few things!