Fast Pointer Nullification for Use-After-Free Prevention
Yubo Du
Network and Distributed System Security (NDSS) Symposium 2026 · Day 3 · Systems Security
This research presents **FPN (Fast Pointer Nullification)**, a significantly more efficient approach to preventing **use-after-free (UAF) vulnerabilities** -- one of the most critical and increasingly common classes of memory safety bugs in low-level software. Previous pointer nullification systems incurred **22-56% runtime overhead** and up to **200% memory overhead**, making them impractical for production deployment. FPN reduces this to **17% runtime overhead** and **8% memory overhead** through two key innovations: **aligned region-based metadata management** (replacing expensive tree traversal or arithmetic operations with a single bit-shift and table lookup) and **coarse-grained block-based registrations** (exploiting the spatial locality of pointer stores to dramatically reduce registration count).
AI review
A well-engineered optimization of pointer nullification for UAF prevention that cuts runtime overhead from 31-56% to 17% and memory overhead from 29-173% to 8%. The spatial locality insight is sound, the region-based metadata addressing is clean, and the shadow table for block-level scanning is a good engineering decision. Not groundbreaking from an exploitation perspective, but it makes a meaningful defense more practical.