A Survey on Thwarting Memory Corruption in RISC-V

Abstract

With embedded devices becoming more pervasive and entrenched in society, it is paramount to keep these systems secure. A threat plaguing these systems consists of software vulnerabilities that cause memory corruption, potentially allowing an attacker to breach the device. Software-based countermeasures exist, but suffer from high overhead. In this survey, we investigate whether this could be mitigated using dedicated hardware. Driven by the advancements of open hardware, we focus on implementations for RISC-V, a novel and open architecture tailored for customization. We distinguish between methods validating memory accesses beforehand, obfuscating information necessary for an attack, and detecting memory values corrupted earlier. We compare on qualitative metrics, such as the security coverage and level of transparency, and performance in both software and hardware. Although current implementations do not easily allow for a fair comparison as their evaluation methodologies vary widely, we show that current implementations are suitable to minimize the runtime overhead with a relatively small area overhead. Nevertheless, we identified that further research is still required to mitigate more fine-grained attacks such as intra-object overflows, to integrate into more sophisticated protected execution environments towards resilient systems that are automatically recoverable, and to move towards more harmonized evaluation.