selinux

This guide explains resolving "Permission Denied" errors on Linux systems, emphasizing SELinux's role as a security module enforcing access controls. Key steps include checking and adjusting SELinux contexts, deploying audit logs to analyze denials, and using tools like `restorecon` and `audit2allow` for troubleshooting and modifying policies. These measures help maintain system security while addressing and managing permissions issues effectively.

Explore the key differences between AppArmor and SELinux, the primary security modules for Linux distributions. AppArmor, favored for its simplicity and ease of use, is standard in Ubuntu, while SELinux offers detailed, context-based security policies ideal for high-security environments and is predominantly used in RHEL. This analysis covers their policy designs, default configurations, and toolsets, catering to both novice and advanced users aiming to enhance system security management.

The article compares the implementation of SELinux in AlmaLinux and Rocky Linux, where it is enabled by default for robust security, with Ubuntu's use of AppArmor, which simplifies security management at an application level. Administrators who require stringent security measures may prefer AlmaLinux or Rocky Linux, while Ubuntu's AppArmor provides easier handling for specific application-focused security needs.

This article provides an in-depth look at Security-Enhanced Linux (SELinux), a mechanism enhancing Linux security via mandatory access control. Developed by the NSA, SELinux operates in three modes—Enforcing, Permissive, and Disabled—to control system access. The guide covers SELinux configuration, management tools installation, policy management, and auditing, aiming to bolster system security against unauthorized access for administrators and security enthusiasts.