On Scheduler Side-Channels in Dynamic-Priority Real-Time Systems

TL;DR

This paper reveals the existence of scheduler side-channels in dynamic-priority real-time systems like EDF, introduces DyPS to exploit these channels, and demonstrates its superior effectiveness over existing methods in inferring task information.

Contribution

The paper is the first to demonstrate scheduler side-channels in dynamic-priority RTS and proposes DyPS, a novel algorithm that outperforms existing methods in attack accuracy.

Findings

DyPS effectively infers critical task information with high precision.

DyPS outperforms ScheduLeak in attacking EDF RTS.

Factors affecting attack success are analyzed using synthetic task sets.

Abstract

While the existence of scheduler side-channels has been demonstrated recently for fixed-priority real-time systems (RTS), there have been no similar explorations for dynamic-priority systems. The dynamic nature of such scheduling algorithms, e.g., EDF, poses a significant challenge in this regard. In this paper we demonstrate that side-channels exist in dynamic priority real-time systems. Using this side-channel, our proposed DyPS algorithm is able to effectively infer, with high precision, critical task information from the vantage point of an unprivileged (user space) task. Apart from demonstrating the effectiveness of DyPS, we also explore the various factors that impact such attack algorithms using a large number of synthetic task sets. We also compare against the state-of-the-art and demonstrate that our proposed DyPS algorithms outperform the ScheduLeak algorithms in attacking the EDF RTS.