Book Image

SELinux System Administration, Third Edition - Third Edition

By : Sven Vermeulen
Book Image

SELinux System Administration, Third Edition - Third Edition

By: Sven Vermeulen

Overview of this book

Linux is a dominant player in many organizations and in the cloud. Securing the Linux environment is extremely important for any organization, and Security-Enhanced Linux (SELinux) acts as an additional layer to Linux system security. SELinux System Administration covers basic SELinux concepts and shows you how to enhance Linux system protection measures. You will get to grips with SELinux and understand how it is integrated. As you progress, you’ll get hands-on experience of tuning and configuring SELinux and integrating it into day-to-day administration tasks such as user management, network management, and application maintenance. Platforms such as Kubernetes, system services like systemd, and virtualization solutions like libvirt and Xen, all of which offer SELinux-specific controls, will be explained effectively so that you understand how to apply and configure SELinux within these applications. If applications do not exert the expected behavior, you’ll learn how to fine-tune policies to securely host these applications. In case no policies exist, the book will guide you through developing custom policies on your own. By the end of this Linux book, you’ll be able to harden any Linux system using SELinux to suit your needs and fine-tune existing policies and develop custom ones to protect any app and service running on your Linux systems.
Table of Contents (22 chapters)
1
Section 1: Using SELinux
8
Section 2: SELinux-Aware Platforms
14
Section 3: Policy Management

Summary

In this chapter, we learned how file contexts are stored as extended attributes on the filesystem and how we can manipulate the contexts of files and other filesystem resources. Next, we found out where SELinux keeps the definitions that describe which SELinux contexts to assign to the files.

We also learned to work with the semanage tool to manipulate this information and worked with a few tools that use this information to enforce contexts on resources.

On the process level, we got our first taste of SELinux policies, identifying when a process launches inside a certain SELinux domain. With it, we covered the sesearch and seinfo applications to query the SELinux policy. Finally, we looked at some of Linux's security implementations that limit the transition scope of applications, which also influences SELinux domain transitions.

In the next chapter, we will expand our knowledge of protecting the operating system through the networking-related features of SELinux...