What is SELinux?

SELinux (Security-Enhanced Linux) is a security mechanism in the Linux kernel that implements Mandatory Access Control (MAC). Unlike traditional models based on user and group permissions (Discretionary Access Control, DAC), SELinux allows for more fine-grained and strict management of which processes and users can access which resources.

Key features of SELinux:

• Security policies define what actions are permitted for processes and users.
• Protects the system from exploits and malicious software by restricting process capabilities.
• Operates at the kernel level, providing a high level of security.

Example: even if a process is run as root, SELinux can deny it access to certain files or network ports if not allowed by policy.

SELinux is often used in enterprise and server systems to enhance security and prevent unauthorized access.