Introduction to SELinux

GitHub Security Lab focuses on enhancing the security of open-source software, including tools like SELinux, which is a Mandatory Access Control (MAC) system integrated into the Linux kernel. SELinux, developed initially by the NSA, operates by assigning security contexts to processes and resources to control access and enhance system security. It contrasts with the more common Discretionary Access Control (DAC) by focusing on the sensitivity of resources rather than ownership. The blog introduces SELinux to developers and administrators, explaining its architecture, including key components like the Security Server and Access Vector Cache, and how it enforces security policies through type enforcement. It also provides practical insights into SELinux policy creation, management, and troubleshooting, highlighting tools and examples to help users navigate its complexities. SELinux's integration with the Linux Security Modules framework allows it to hook into the kernel and manage permissions, offering a robust security mechanism widely implemented in systems like Android and Red Hat.