How to Enable or Disable SELinux Boolean Values

Security-Enhanced Linux (SELinux) is a security mechanism for mandatory access control (MAC) implemented in the Linux kernel. It is a flexible operation designed to boost overall system security: it enables access controls imposed using a policy loaded on the system which may not be changed by normal users or misbehaving programs.

The following article clearly explains about SELinux and how to implement it in your Linux system.

1. Implementing Mandatory Access Control with SELinux or AppArmor in Linux

In this article, we will show you how to turn on or off SELinux boolean values in CentOS, RHEL and Fedora Linux distributions.

To view all SELinux booleans, use the getsebool command together with less command.

Note: SELinux must be in enabled state to list all booleans.

# getsebool -a | less

To view all boolean values for a specific program (or daemon), use the grep utility, the following command shows you all httpd booleans.

# getsebool -a | grep httpd

To turn on (1) or off (0) SELinux booleans, you can use setsebool program as described below.

Enable or Disable SELinux Boolean Values

If you have a web server installed on your system, you can permit HTTPD scripts to write files in directories labeled public_content_rw_t by enabling the allow_httpd_sys_script_anon_write boolean.

# getsebool allow_httpd_sys_script_anon_write 
# setsebool allow_httpd_sys_script_anon_write on
OR
# setsebool allow_httpd_sys_script_anon_write 1

Similarly, to disable or turn off above SELinux boolean value, run the following command.

# setsebool allow_httpd_sys_script_anon_write off
# setsebool allow_mount_anyfile off
OR
# setsebool allow_httpd_sys_script_anon_write  0
# setsebool allow_mount_anyfile  0

You can find the meaning of all the SELinux booleans at https://wiki.centos.org/TipsAndTricks/SelinuxBooleans

Don’t forget to read these following security related articles.

1. How to Disable SELinux Temporarily or Permanently in RHEL/CentOS
2. Mandatory Access Control Essentials with SELinux
3. The Mega Guide to Hardening and Securing CentOS 7

In this article, we have explained how to enable or disable SELinux boolean values in CentOS, RHEL and Fedora distributions. If you have any questions, do ask via the comment from below.