Building Bridges: Safe Interactions with Foreign Languages through Omniglot

Memory- and type-safe languages promise to eliminate entire classes of systems vulnerabilities by construction. In practice, though, even clean-slate systems often need to incorporate libraries written in other languages with fewer safety guarantees. Because these interactions threaten the soundness of safe languages, they can reintroduce the exact vulnerabilities that safe languages prevent in the first place. This paper presents Omniglot: the first framework to efficiently uphold safety and soundness of Rust in the presence of unmodified and untrusted foreign libraries. Omniglot facilitates interactions with foreign code by integrating with a memory isolation primitive and validation infrastructure, and avoids expensive operations such as copying or serialization. We implement Omniglot for two systems: we use it to integrate kernel components in a highly-constrained embedded operating system kernel, as well as to interface with conventional Linux userspace libraries. Omniglot performs comparably to approaches that deliver weaker guarantees and significantly better than those with similar safety guarantees.