I'm working on a multi-language project, where I need to pass complex data structures from rust to other language (e.g. go, c#, etc). It is done by creating a raw pointer (e.g. Box::into_raw(Box::new(data))). To avoid memory leaks I do another FFI call, which deferences the pointer to reclaim the memory (Box::leak(Box::from_raw(ptr as *mut Data))).

That works, but MIRI blames the code for integer-to-pointer cast and missing pointer provenance. Is there a way to dump provenance into a variable to pass it through FFI boundaries or solve it by other means?

Rust playground with a PoC. (Tools -> Miri)