Table of Contents

Introduction to the Red Hat SELinux Guide .................................................................................... i

1. What Is SELinux? .................................................................................................................. i

2. Prerequisites for This Guide ................................................................................................. ii

3. Conventions for SELinux Directories and Files ..................................................................iii

4. Document Conventions........................................................................................................iii

5. Code Presentation Conventions ........................................................................................... vi

6. Activate Your Subscription ................................................................................................. vii

6.1. Provide a Red Hat Login...................................................................................... vii

6.2. Provide Your Subscription Number ....................................................................viii

6.3. Connect Your System..........................................................................................viii

7. More to Come ....................................................................................................................viii

7.1. Send in Your Feedback .......................................................................................viii

I. Understanding SELinux .................................................................................................................. i

1. SELinux Architectural Overview.......................................................................................... 1

1.1. Flask Security Architecture and SELinux.............................................................. 1

1.2. SELinux, an Implementation of Flask ................................................................... 3

2. SELinux Policy Overview..................................................................................................... 5

2.1. What Is Policy? ...................................................................................................... 5

2.2. Where is the Policy? .............................................................................................. 6

2.3. Policy Role in Boot................................................................................................ 7

2.4. File System Security Contexts ............................................................................... 8

2.5. Object Classes and Permissions........................................................................... 10

2.6. TE Rules   Attributes ........................................................................................... 12

2.7. TE Rules   Types.................................................................................................. 17

2.8. TE Rules   Access Vectors................................................................................... 19

2.9. Policy Macros ...................................................................................................... 21

2.10. SELinux Users and Roles .................................................................................. 24

2.11. TE Rules   Constraints ....................................................................................... 26

2.12. Special Interfaces and File Systems................................................................... 27

3. Targeted Policy Overview ................................................................................................... 29

3.1. What is the Targeted Policy?................................................................................ 29

3.2. Files and Directories of the Targeted Policy ........................................................ 30

3.3. Understanding the File Contexts Files ................................................................. 38

3.4. Common Macros in the Targeted Policy.............................................................. 39

3.5. Understanding the Roles and Users in the Targeted Policy ................................. 42

4. Example Policy Reference  

dhcpd

.................................................................................... 47

4.1. Policy File Locations ........................................................................................... 47

4.2. Policy Types  

dhcpd

........................................................................................... 47

4.3. Boolean Values for

dhcpd

................................................................................... 51

II. Working With SELinux............................................................................................................... 53

5. Controlling and Maintaining SELinux ............................................................................... 55

5.1. End User Control of SELinux.............................................................................. 55

5.2. Administrator Control of SELinux ...................................................................... 61

5.3. Analyst Control of SELinux ................................................................................ 70

5.4. Policy Writer Control of SELinux ....................................................................... 71

6. Tools for Manipulating and Analyzing SELinux................................................................ 73

6.1. Information Gathering Tools................................................................................ 73

6.2. Using seaudit for Audit Log Analysis................................................................. 76

6.3. Using apol for Policy Analysis............................................................................ 83

6.4. Performance Tuning............................................................................................. 89

7. Compiling SELinux Policy ................................................................................................. 91

7.1. Policy Compile Procedure ................................................................................... 91

7.2. What Happens During Policy Build .................................................................... 93