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 2

  1. Administrators should first analyze the situation to see why a problem is being triggered. Perhaps the problem is due to an incorrectly assigned context, or the process has not been started using the correct methods.

    If the denial itself were to be allowed, administrators should create an update to the SELinux policy (just like they would update firewall rules as required).

    If this is not feasible, then administrators should consider putting SELinux in permissive mode, but only for that particular application that is causing problems.

    If that is also not feasible, then administrators should put the system in permissive mode, but making sure that this is accepted by the organization and security principles of the environment.

    Only if even this is not feasible or solves the problem should an administrator shake their head, curse the higher powers, and disable SELinux.

  2. If the system has the audit daemon running, then SELinux logging will be part of the audit logs. They...