Fine-Grained Patching via Contention Balancer: A Practical Mitigation Strategy for Spectre Vulnerabilities Using SpecScope Contention Maps

Najmeh Nazari1, Banafsheh Saber Latibari2, Behnam Omidi3, Hosein Mohammadi Makrani1, Fatemeh Movafagh4, Seyede Elahe Hosseini Imeni5, Chongzhou Fang6, Khaled khasawneh3, Houman Homayoun1, Hossein Sayadi7
1UC Davis, 2University of Arizona, 3George Mason University, 4Simon Fraser University, 5University of California Davis, 6Rochester Institute of Technology, 7California State University, Long Beach


Abstract

Spectre attacks exploit speculative execution to leak sensitive data, especially in Artificial Intelligence (AI) workloads, through microarchitectural side channels, posing persistent challenges to modern processors. While advanced defenses like adaptive contention monitoring and resource isolation offer strong protection, they often require costly hardware redesigns. To provide a practical alternative, we introduce Contention Balancer, a fine-grained, software-level mitigation that leverages SpecScope's automated gadget identification and contention mapping. By injecting carefully selected balancing instructions into speculative paths, Contention Balancer equalizes execution characteristics between transient and non-transient paths, effectively masking contention-based side-channel signals without altering program behavior. This approach delivers immediate, low-overhead protection against Spectre vulnerabilities, offering a deployable and cost-effective solution for securing computing systems in the AI era.