FreeGuard: A Faster Secure Heap Allocator

In spite of years of improvements to software security, heap-related attacks still remain a severe threat. One reason is that many existing memory allocators fall short in a variety of aspects. For instance, performance-oriented allocators are designed with very limited countermeasures against attacks, but secure allocators generally su er from signi cant performance overhead, e.g., running up to 10× slower. This paper, therefore, introduces FreeGuard, a secure memory allocator that prevents or reduces a wide range of heaprelated attacks, such as heap over ows, heap over-reads, use-afterfrees, as well as double and invalid frees. FreeGuard has similar performance to the default Linux allocator, with less than 2% overhead on average, but provides signi cant improvement to security guarantees. FreeGuard also addresses multiple implementation issues of existing secure allocators, such as the issue of scalability. Experimental results demonstrate that FreeGuard is very e ective in defending against a variety of heap-related attacks.