Memory safety continues to be a significant software reliability and security problem, and low overhead and low complexity hardware solutions have eluded computer designers. In this paper, we explore a pathway to deployable memory safety defenses. Our technique builds on a recent trend in software: the usage of binning memory allocators. We observe that if memory allocation sizes (e.g., malloc sizes) are made an architectural feature, then it is possible to overcome many of the thorny issues with traditional approaches to memory safety such as compatibility with unsecured software and significant performance degradation. We show that our architecture, No-FAT, incurs an overhead of 8% on SPEC CPU2017 benchmarks, and our VLSI measurements show low power and area overheads. Finally, as No-FAT’s hardware is aware of the memory allocation sizes, it effectively mitigates certain speculative attacks (e.g., Spectre-V1) with no additional cost. When our solution is used for pre-deployment fuzz testing it can improve fuzz testing bandwidth by an order of magnitude compared to state-of-the-art approaches.

A large class of today’s systems require high levels of availability and security. Unfortunately, state-of-the-art security solutions tend to induce crashes and raise exceptions when under attack, trading off availability for security. In this work, we propose ZeRØ, a pointer integrity mechanism that can continue program execution even when under attack. ZeRØ proposes unique memory instructions and a novel metadata encoding scheme to protect code and data pointers. The combination of instructions and metadata allows ZeRØ to avoid explicitly tagging every word in memory, eliminating performance overheads. Moreover, ZeRØ is a deterministic security primitive that requires minor microarchitectural changes. We show that ZeRØ is better than commercially available state-of-the-art hardware primitives, e.g., ARM’s Pointer Authentication (PAC), by a significant margin. ZeRØ incurs zero performance overheads on the SPEC CPU2017 benchmarks, and our VLSI measurements show low power and area overheads.

Recent rapid strides in memory safety tools and hardware have improved software quality and security. While coarse-grained memory safety has improved, achieving memory safety at the granularity of individual objects remains a challenge due to high performance overheads usually between ~1.7x--2.2x. In this paper, we present a novel idea called Califorms, and associated program observations, to obtain a low overhead security solution for practical, byte-granular memory safety.

The RV144 clinical trial showed the partial efficacy of a vaccine regimen with an estimated vaccine efficacy (VE) of 31% for protecting low-risk Thai volunteers against acquisition of HIV-1. The impact of vaccine-induced immune responses can be investigated through sieve analysis of HIV-1 breakthrough infections (infected vaccine and placebo recipients). A V1/V2-targeted comparison of the genomes of HIV-1 breakthrough viruses identified two V2 amino acid sites that differed between the vaccine and placebo groups. Here we extended the V1/V2 analysis to the entire HIV-1 genome using an array of methods based on individual sites, k-mers and genes/proteins. We identified 56 amino acid sites or "signatures" and 119 k-mers that differed between the vaccine and placebo groups. Of those, 19 sites and 38 k-mers were located in the regions comprising the RV144 vaccine (Env-gp120, Gag, and Pro). The nine signature sites in Env-gp120 were significantly enriched for known antibody-associated sites (p = 0.0021). In particular, site 317 in the third variable loop (V3) overlapped with a hotspot of antibody recognition, and sites 369 and 424 were linked to CD4 binding site neutralization. The identified signature sites significantly covaried with other sites across the genome (mean = 32.1) more than did non-signature sites (mean = 0.9) (p < 0.0001), suggesting functional and/or structural relevance of the signature sites. Since signature sites were not preferentially restricted to the vaccine immunogens and because most of the associations were insignificant following correction for multiple testing, we predict that few of the genetic differences are strongly linked to the RV144 vaccine-induced immune pressure. In addition to presenting results of the first complete-genome analysis of the breakthrough infections in the RV144 trial, this work describes a set of statistical methods and tools applicable to analysis of breakthrough infection genomes in general vaccine efficacy trials for diverse pathogens.