Linux File Permission Overview
Linux file permission system is a foundational security mechanism that controls access to files and directories based on three roles: the owner, group, and others, with three permission types: read, write, and execute. These permissions determine who can view, modify, or execute a file, enabling fine-grained control over system resources. Permissions are represented numerically (e.g., 755) or symbolically (e.g., rwxr-xr-x) and can be modified using commands like chmod, chown, and chgrp. This system benefits defense security by implementing the principle of least privilege, ensuring users and processes only have access to what they need, thereby reducing the attack surface. Additionally, special permissions like setuid, setgid, and sticky bits enhance control over execution and file management, further hardening the system against unauthorized access or tampering.
