1. SPECWANDS: An Efficient Priority-based Scheduler Against Speculation Contention Attacks
- Author
-
Tang, Bowen, Wu, Chenggang, Yew, Pen-Chung, Zhang, Yinqian, Xie, Mengyao, Lai, Yuanming, Kang, Yan, Wang, Wei, Wei, Qiang, and Wang, Zhe
- Subjects
FOS: Computer and information sciences ,Computer Science - Cryptography and Security ,Hardware Architecture (cs.AR) ,Computer Science - Hardware Architecture ,Cryptography and Security (cs.CR) - Abstract
Transient Execution Attacks (TEAs) have gradually become a major security threat to modern high-performance processors. They exploit the vulnerability of speculative execution to illegally access private data, and transmit them through timing-based covert channels. While new vulnerabilities are discovered continuously, the covert channels can be categorised to two types: 1) Persistent Type, in which covert channels are based on the layout changes of buffering, e.g. through caches or TLBs; 2) Volatile Type, in which covert channels are based on the contention of sharing resources, e.g. through execution units or issuing ports. The defenses against the persistent-type covert channels have been well addressed, while those for the volatile-type are still rather inadequate. Existing mitigation schemes for the volatile type such as Speculative Compression and Time-Division-Multiplexing will introduce significant overhead due to the need to stall the pipeline or to disallow resource sharing. In this paper, we look into such attacks and defenses with a new perspective, and propose a scheduling-based mitigation scheme, called SPECWANDS. It consists of three priority-based scheduling policies to prevent an attacker from transmitting the secret in different contention situations. SPECWANDS not only can defend against both inter-thread and intra-thread based attacks, but also can keep most of the performance benefit from speculative execution and resource-sharing. We evaluate its runtime overhead on SPEC 2017 benchmarks and realistic programs. The experimental results show that SPECWANDS has a significant performance advantage over the other two representative schemes.
- Published
- 2023
- Full Text
- View/download PDF