Security-Enhanced Linux (SELinux) is a Linux kernel security module that provides a mechanism for enforcing mandatory access control (MAC) policies. It is designed to enhance the overall security of your Linux system by restricting processes and users to the minimum privileges necessary for their tasks. While SELinux can significantly improve your system’s security posture, there are situations where you may need to disable it temporarily or permanently, such as during troubleshooting or when deploying specific applications that are not compatible with SELinux.
In this guide, we will demonstrate how to disable SELinux on RHEL 7, CentOS 7, and Oracle Linux 7. Following these steps will help you disable SELinux safely and effectively, ensuring that your system operates as intended without the restrictions imposed by SELinux. It is crucial to understand the security implications of disabling SELinux and to re-enable it whenever possible to maintain the highest level of system security.
Step 1: Check SELinux Status
Before making any changes, it is essential to check the current SELinux status on your system. Use the following command to do so:
sestatus
This command will display the SELinux status, mode, and policy being used.
# sestatus SELinux status: enabled SELinuxfs mount: /sys/fs/selinux SELinux root directory: /etc/selinux Loaded policy name: targeted Current mode: enforcing Mode from config file: enforcing Policy MLS status: enabled Policy deny_unknown status: allowed Max kernel policy version: 28
Step 2: Temporarily Disable SELinux
To temporarily disable SELinux until the next system reboot, use the following command:
sudo setenforce 0
You can re-enable SELinux without rebooting by running:
sudo setenforce 1
Keep in mind that these changes are temporary and will not persist after a reboot.
Step 3: Permanently Disable SELinux
To permanently disable SELinux, follow these steps:
Open the SELinux configuration file using your preferred text editor:
sudo nano /etc/selinux/config
Change the “SELINUX” line to “disabled”:
# This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - No SELinux policy is loaded. SELINUX=disabled # SELINUXTYPE= can take one of these two values: # targeted - Targeted processes are protected, # minimum - Modification of targeted policy. Only selected processes are protected. # mls - Multi Level Security protection. SELINUXTYPE=targeted
Save the changes and exit the text editor.
Reboot your system for the changes to take effect:
sudo reboot
After the system reboots, SELinux should be permanently disabled.
# sestatus SELinux status: disabled
Commands Mentioned:
- sestatus – A command to check the current SELinux status, mode, and policy.
- setenforce – A command to temporarily enable or disable SELinux enforcement.
- nano – A user-friendly text editor for the command line.
- reboot – A command to restart the system.
Conclusion
By following this guide, you have successfully disabled SELinux on RHEL 7, CentOS 7, and Oracle Linux 7, either temporarily or permanently. Disabling SELinux can be necessary in certain situations, such as troubleshooting or deploying specific applications. However, it is essential to remember the security implications of disabling SELinux and to re-enable it whenever possible to maintain a secure system.
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