CRII: SaTC: Mitigating Software-Based Microarchitectural Attacks via Secure Microcode Customization

现代高性能处理器实现了复杂的微架构优化，包括推测执行，最近被证明很容易受到一种名为Spectre的恶意攻击。该项目将研究一个微架构解决方案框架，以防止此类攻击。这个框架被称为上下文敏感防护（context-sensitive fencing），它将寻求动态地自动跟踪和检测恶意执行模式，从而在没有程序员干预的情况下触发防御代码，并且对处理器性能的影响最小。本研究将探讨一种高性能防御策略，该策略包含三个新的组成部分：(a)安全的微码定制，利用处理器的微码引擎，使幽灵防御代码（例如，推测栅栏）的外科手术注入到动态指令流，而不需要软件补丁；(b)一个解码器级信息流跟踪框架，检测虚假的执行模式，导致错误的训练核心微处理器结构，如分支预测器；(c)微体系结构加固机制，保护敏感的微体系结构免受投机执行的恶意副作用，进一步实现安全感知的处理器体系结构设计。本研究提出的可重构微码级防御可以解决影响数百万用户的“幽灵”攻击。该项目将对研究生和本科生进行培训和指导，并有望促进硬件安全课程的开发，该课程将在课堂和在线上授课。这项研究的结果将以出版物、演示、设计报告、课程材料和源代码的形式传播，并将在本项目期间或之后在研究者的网站http://www.cs.virginia.edu/venkat.This上公开发布。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Modern high-performance processors implement complex microarchitectural optimizations involving speculative execution which has recently been shown to be vulnerable to a type of malicious attack called Spectre. This project will investigate a microarchitectural solution framework to secure against such attacks. This framework, called context-sensitive fencing, will seek to automatically track and detect malicious execution patterns dynamically to trigger defense code without programmer intervention and with minimal impact on processor performance.This research will investigate a high performance defense strategy with three novel components: (a) secure microcode customization which leverages the processor's microcode engine to enable the surgical injection of Spectre defense code (e.g., speculation fences) into the dynamic instruction stream without the need for software patching, (b) a decoder-level information flow tracking framework which detects spurious execution patterns that result in the mis-training of core microprocessor structures such as the branch predictor, and (c) microarchitecture hardening mechanisms that shield sensitive microarchitectural structures against the malicious side effects of speculative execution, to further enable a security-aware processor architecture design.The reconfigurable microcode-level defense proposed by this research may address the Spectre attack which affects millions of users. This project will train and mentor graduate and undergraduate students and is expected to facilitate development of a hardware security course to be delivered in-class and online.The results from this research will be disseminated in the form of publications, presentations, design reports, course materials, and source code, and will be hosted publicly for the length of this project and beyond, on the investigator's website at http://www.cs.virginia.edu/venkat.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.