Exploring GrapheneOS secure allocator: Hardened Malloc

GrapheneOS, a privacy-focused mobile OS based on Android, introduced a new secure memory allocator called hardened malloc to enhance security against memory corruption vulnerabilities. The allocator is designed to protect processes and implements security features like Extended Address Space and Secure App Spawning. It also leverages the Memory Tagging Extension (MTE) on compatible devices to prevent memory corruption. Hardened malloc isolates metadata from user data and uses a two-stage quarantine system for freed slots, adding a layer of defense against use-after-free vulnerabilities. The allocator's robust security mechanisms make it challenging for attackers to exploit memory corruption vulnerabilities like heap overflow and use-after-free.