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 10

  1. SELinux works within the Linux kernel. Xen, however, is a hypervisor that sits between the hardware and the operating systems and does not use a full operating system as its base (unlike, for instance, QEMU and KVM).

    When we interact with Xen through Linux, we are actually interacting with Xen through the dom0 guest. Within this guest, SELinux can be running (and we even recommend it), but SELinux will remain within the virtualized guest.

    Xen, however, copied the SELinux approach and implemented it in its Xen Security Module framework.

  2. You can assign a label to a Xen guest by editing its configuration file (inside /etc/xen) and adding the seclabel parameter, like so:
    seclabel = 'system_u:system_r:prot_domU_t'

    You will need to relaunch the guest for the changes to take effect. Once the guest is booted again (using xl create), you can see its active label using xl list -Z.

    What are the common Xen commands that deal with XSM labels?

    The common commands to use...