PAC it up: Towards Pointer Integrity using ARM Pointer Authentication

TL;DR

This paper introduces PARTS, a framework that leverages ARM Pointer Authentication to enhance runtime pointer security, including data pointers, providing stronger protection against memory attacks with manageable performance costs.

Contribution

It presents the first PA-based mechanism for data pointer integrity and integrates it into LLVM and Linux, improving runtime protection against memory vulnerabilities.

Findings

PARTS outperforms existing solutions in protecting against memory attacks.

The framework introduces minimal performance overhead.

It demonstrates effective integration of PA into software defenses.

Abstract

Run-time attacks against programs written in memory-unsafe programming languages (e.g., C and C++) remain a prominent threat against computer systems. The prevalence of techniques like return-oriented programming (ROP) in attacking real-world systems has prompted major processor manufacturers to design hardware-based countermeasures against specific classes of run-time attacks. An example is the recently added support for pointer authentication (PA) in the ARMv8-A processor architecture, commonly used in devices like smartphones. PA is a low-cost technique to authenticate pointers so as to resist memory vulnerabilities. It has been shown to enable practical protection against memory vulnerabilities that corrupt return addresses or function pointers. However, so far, PA has received very little attention as a general purpose protection mechanism to harden software against various classes of memory attacks. In this paper, we use PA to build novel defenses against various classes of run-time attacks, including the first PA-based mechanism for data pointer integrity. We present PARTS, an instrumentation framework that integrates our PA-based defenses into the LLVM compiler and the GNU/Linux operating system and show, via systematic evaluation, that PARTS provides better protection than current solutions at a reasonable performance overhead