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

Chapter 4: Using File Contexts and Process Domains

SELinux-enabled systems are strongly dependent on the notion of contexts (on resources) and domains (on processes). The access controls that SELinux enforces use these contexts to identify the resources, and define the enforcement rules within the policy. Because of its inherent reliance on these contexts, this chapter will go into detail on file contexts, context definitions, and process domains.

We will work with the file contexts and learn where they are stored so that you can easily adjust your system to work optimally with SELinux. We assign contexts to resources both temporarily (for testing purposes) and permanently, and learn how these contexts are used to automatically deduce the process domain. Once we know how to obtain process domain information, we will query the SELinux policy to learn about the current access controls.

In this chapter, we're going to cover the following main topics:

  • Introduction to...