SELinux Interview Questions
1) What are Booleans?
Answer: Booleans are SELinux policy rules which changes behaviour of selinux policies. Booleans can be enabled/disabled.
2) What parameter can be set at boot time to enable/disable SELinux?
Answer:
For Enableling SELinux: selinux=1 OR enforcing=1
For Disabling SELinux: selinux=0 OR enforcing=0
3) What is the main configuration file for SELinux where the SELinux status can be changed permanently?
Answer: /etc/selinux/config
4) Where SELinux violation logs are generated?
Answer: /var/log/audit/audit.log
5) How to enable SELinux logs to be sent to /var/log/messages?
Answer: Install setroubleshoot-server package. setroubleshootd services will generate SELinux logs in /var/log/messages.
6) How to display SELinux policies which are manually changed/modified?
Answer: # semanage boolean -l -C
7) What is the importance of hidden file /.autorelabel?
Answer: At boot time, init.rc checks for the existence of /.autorelabel. If this file exists, SELinux performs a complete file system relabel (using the /sbin/fixfiles -f -F relabel command), and then deletes /.autorelabel.
Note: If the system is starting from Disabled mode, then you have to reboot and relabel the system twice, first in Permissive mode, then in Enforcing.