L4 Pointer: An efficient pointer extension for spatial memory safety support without hardware extension

TL;DR

L4 Pointer introduces a 128-bit pointer extension leveraging SIMD operations to enhance spatial memory safety with lower overhead, avoiding hardware modifications and outperforming existing software-only methods.

Contribution

It proposes a novel 128-bit pointer extension called L4 Pointer that improves spatial memory safety support efficiently without hardware assistance.

Findings

L4 Pointer achieves lower runtime overhead compared to existing methods.

It demonstrates higher performance using SIMD operations.

The approach avoids the need for hardware modifications.

Abstract

Since buffer overflow has long been a frequently occurring, high-risk vulnerability, various methods have been developed to support spatial memory safety and prevent buffer overflow. However, every proposed method, although effective in part, has its limitations. Due to expensive bound-checking or large memory in taking for metadata, the software-only support for spatial memory safety inherently entails runtime overhead. Contrastingly, hardware-assisted methods are not available without specific hardware assistants. To mitigate such limitations, Herein we propose L4 Pointer, which is a 128-bit pointer extended from a normal 64-bit virtual addresses. By using the extra bits and widespread SIMD operations, L4 Pointer shows less slow-down and higher performance without hardware extension than existing methods.