Book Image

SELinux System Administration

By : Sven Vermeulen
Book Image

SELinux System Administration

By: Sven Vermeulen

Overview of this book

NSA Security-Enhanced Linux (SELinux) is a set of patches and added utilities to the Linux kernel to incorporate a strong, flexible, mandatory access control architecture into the major subsystems of the kernel. With its fine-grained yet flexible approach, it is no wonder Linux distributions are firing up SELinux as a default security measure. SELinux System Administration covers the majority of SELinux features through a mix of real-life scenarios, descriptions, and examples. Everything an administrator needs to further tune SELinux to suit their needs are present in this book. This book touches on various SELinux topics, guiding you through the configuration of SELinux contexts, definitions, and the assignment of SELinux roles, and finishes up with policy enhancements. All of SELinux's configuration handles, be they conditional policies, constraints, policy types, or audit capabilities, are covered in this book with genuine examples that administrators might come across. By the end, SELinux System Administration will have taught you how to configure your Linux system to be more secure, powered by a formidable mandatory access control.
Table of Contents (13 chapters)

Chapter 2. Understanding SELinux Decisions and Logging

Once SELinux is enabled on a system, it starts its access control functionality as described in the previous chapter. This however might have some unwanted side effects, so in this chapter, we will:

  • Switch between SELinux in full enforcement mode (host-based intrusion prevention) versus its permissive, logging-only mode (host-based intrusion detection)

  • Use various methods to toggle the SELinux state (enabled or disabled, permissive or enforcing)

  • Disable SELinux protections for a single domain rather than the entire system

  • Learn to interpret the SELinux log events that describe to us what activities that SELinux has prevented

We finish with an overview of common methods for analyzing these logging events in day-to-day operations.