ProGIP: Protecting Gradient-Based Input Perturbation Approaches for OOD Detection from Soft Errors

Abstract

Undetected out-of-distribution (OOD) inputs pose a significant threat to the reliability of deep learning models, as they may lead to unexpected behaviors during inference. Several studies have proposed effective OOD input detection methods. However, soft errors-another significant threat to reliability-can impact both the classification results of neural network models and the ID/OOD detections of OOD detection methods. To provide a resilient OOD detection solution against soft errors, we analyze the effect of soft errors on neural network models with gradient-based input perturbation (GIP) approaches, which are representative methods for OOD detection. Building on our analysis, we propose ProGIP, which incorporates two software-level range-based fault detectors to protect all execution phases of GIP approaches, including two forward passes and one backward pass. Because it is purely software-based and adds just two scalar comparisons, ProGIP is readily deployable even on resource-constrained embedded platforms. Our ProGIP solution enables GIP approaches to distinguish between ID, OOD, and fault-affected inferences, detecting 97.7% of critical faults with a negligible runtime overhead of only 0.84%. Experimental results with 2.4 million fault injections across various neural networks and OOD detection methods demonstrate ProGIP's effectiveness in ensuring comprehensive reliability against non-malicious threats.