I started writing this review half a dozen times, and still had problems explaining What Went Wrong. Going in, I was interested how SELinux was set up on one or more systems, what it did, how to modify the settings, and when I should (and shouldn't).
This book is very heavy on theory, and extremely dry. It's use of examples are few and scattered, and only served to illustrate some immediate point. Think of a boring class where you try to absorb the theory and stay awake long enough to actually try some of the examples at the end of the class.
What I would like to see is a working system right up front. Show the results of an action prohibited by SELinux, then contrast it with one prohibited by Linux traditional security. Show what an admin would do to authorize the action for that user or group. In short, simulate a working system. From there, introduce theory.
I give this book a 3.5 out of 10. It may have a lot of useful information in it, but the pages tended to blur together.