TrustZone Intermezzo: Broken OP-TEE Memory Isolation on i.MX 8M
Summary
This security research blog post analyzes a TrustZone memory isolation bypass on i.MX 8M caused by TZASC region0 aliasing and interactions with OP-TEE, Linux, and bootloaders. It demonstrates a proof-of-concept that OP-TEE memory could be accessed from the normal world under certain configurations, explains root causes, and provides mitigation guidance including upgrading OP-TEE, TF-A, and bootloaders, with a note that no CVEs were filed at publication.