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

The Xen hypervisor is quite different from the QEMU and KVM hypervisors, which are more readily used in libvirt. SELinux support for Xen is also different than sVirt as the SELinux subsystem can only be active inside Xen guests, and SELinux does not see other guests.

Xen has resolved that by implementing its own SELinux copy as XSM-FLASK and has integrated the appropriate support for the XSM-FLASK labels in its own tooling. In this chapter, we've learned how to apply our own types to Xen guests, toggle the XSM state, toggle XSM booleans, and even how we can build and load our own XSM-FLASK policy.

In the next chapter, we'll look at container workloads and how SELinux can help administrators to further harden and secure their container runtimes. We will see how sVirt can be applied to container runtimes, and how the tooling deals with SELinux support.