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 14

  1. An unconfined domain is still fully controlled and enforced by SELinux. It is called unconfined because such domains are granted extensive privileges by the SELinux policy. However, unlike what the name implies, they are still somewhat confined.

    Permissive domains, on the contrary, are not confined. SELinux will only log violations against the policy, but it will not enforce them.

  2. The SELinux sandbox utility can be used to run applications in a very restricted domain. The utility will both force the application to run in a very restricted domain (sandbox_t for regular, non-graphical end user applications, or sandbox_xserver_t for graphical applications), as well as isolate or hide access to other system resources through the use of Linux's namespaces.
  3. When the init system (such as systemd) launches a daemon, it will execute a specific binary or script for it. The label of this binary or script will generally define the target domain. For instance, if the...