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

Getting help with denials

On some distributions, additional support tools are available that help us identify the cause of a denial. These tools have some knowledge of common mistakes (for instance, setting the right context on files to allow the web server to read them). Other distributions require us to use our experience to make proper decisions, supporting us through the distribution mailing lists, bug tracking sites, and other cooperation locations—for example, Internet Relay Chat (IRC).

Troubleshooting with setroubleshoot

In CentOS (and other Red Hat Enterprise Linux (RHEL)-related distributions such as Fedora), additional tools are present that help us troubleshoot denials. The tools work together to catch a denial, look for a plausible solution, and inform the administrator about the denial and its suggested resolutions.

When used on a graphical workstation, denials can even result in popups that ask the administrator to review them immediately. Install the...