xzone malloc: memory allocator for Apple OS platforms (github.com)

Apple has introduced **xzone malloc**, a memory allocator designed for its operating systems, focusing on enhancing memory safety while delivering high performance. This new allocation system is part of Apple's **Memory Integrity Enforcement** technology and aims to combat heap memory safety vulnerabilities through innovative security features. Significantly, xzone malloc employs **bucketed type isolation**, where memory allocations are grouped into distinct buckets based on their types, preventing allocations from different buckets from sharing the same virtual address. This design mitigates use-after-free vulnerabilities, making exploitation more challenging. Additional features include zero-on-free, externalized metadata, probabilistic guard pages, and support for **Memory Tagging Extension (MTE)**. The allocator balances security and fragmentation, allowing for context-aware deployments that cater to specific memory and security requirements, enhancing overall application robustness in the face of evolving security threats.