Book Image

Practical Linux Security Cookbook

By : Michael A Lindner, Tajinder Kalsi
Book Image

Practical Linux Security Cookbook

By: Michael A Lindner, Tajinder Kalsi

Overview of this book

With the growing popularity of Linux, more and more administrators have started moving to the system to create networks or servers for any task. This also makes Linux the first choice for any attacker now. Due to the lack of information about security-related attacks, administrators now face issues in dealing with these attackers as quickly as possible. Learning about the different types of Linux security will help create a more secure Linux system. Whether you are new to Linux administration or experienced, this book will provide you with the skills to make systems more secure. With lots of step-by-step recipes, the book starts by introducing you to various threats to Linux systems. You then get to walk through customizing the Linux kernel and securing local files. Next you will move on to manage user authentication locally and remotely and also mitigate network attacks. Finally, you will learn to patch bash vulnerability and monitor system logs for security. With several screenshots in each example, the book will supply a great learning experience and help you create more secure Linux systems.
Table of Contents (17 chapters)
Practical Linux Security Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Debugging a kernel on boot


Sometimes, your system might fail to boot changes within the kernel. Hence, it is important that when you're creating reports about these failures, all the appropriate information about debugging is included. This will be useful for the kernel team in order to resolve the issue.

How to do it…

If you are trying to capture error messages that appear during boot, then it is better to boot the kernel with the quiet and splash options removed. This helps you to see messages, if any, that appear on the screen.

To edit the boot option parameters, perform the following steps:

  1. Boot the machine.

  2. During the BIOS screen, press the Shift key and hold it down. You should see the Grub menu after the BIOS loads.

  3. Navigate to the kernel entry that you want to boot and press e.

  4. Then, remove the quiet and splash keywords (these can be found in the line starting with Linux)

  5. Press Ctrl + x to boot.

You can see error messages, if any, on the screen.

Depending on the type of error messages you...