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 7: Configuring Application-Specific SELinux Controls

Several Linux services and applications enable additional SELinux controls besides the kernel-enforced SELinux policy. They allow the administrator to further manipulate and enforce policy rules through the application itself—isolating users, reducing data leakage risks, and mitigating the impact of malicious behavior.

In this chapter, we will look at several SELinux-aware applications, such as systemd services and how they allow administrators to set up and specify target domains and resource labels. We'll also cover the D-Bus service, which allows SELinux policies to control the service binding and message communication within D-Bus itself. Next, we'll jump to PAM-enabled services that allow users to log in through them.

Finally, we'll end the chapter with mod_selinux, an Apache module that allows SELinux-specific tuning of the web server's behavior. This approach shows how applications...