ShadowBound: Efficient Heap Memory Protection Through Advanced Metadata Management and Customized Compiler Optimization

Abstract: In software development, the prevalence of unsafe languages such as C and C++ introduces potential vulnerabilities, especially within the heap, a pivotal component for dynamic memory allocation. Despite its significance, heap management complexities have made heap corruption pervasive, posing severe threats to system security. While prior solutions aiming for temporal and spatial memory safety exhibit overheads deemed impractical, we present ShadowBound, a unique heap memory protection design. At its core, ShadowBound is an efficient out-of-bounds defense that can work with various use-after-free defenses (e.g. MarkUs, FFMalloc, PUMM) without compatibility constraints. We harness a shadow memory-based metadata management mechanism to store heap chunk boundaries and apply customized compiler optimizations tailored for boundary checking. We implemented ShadowBound atop the LLVM framework and integrated three state-of-the-art use-after-free defenses. Our evaluations show that ShadowBound provides robust heap protection with minimal time and memory overhead, suggesting its effectiveness and efficiency in safeguarding real-world programs against prevalent heap vulnerabilities.