That's not the reason why C/C++ code that uses a linked list is "unsafe". It's "unsafe" because it doesn't protect the use. In other words, because the client code is itself "unsafe". If the use was protected (whether dynamically with a lock or statically by some Rust-like language extension, I don't care), there was no more of an issue than in Rust.

And if the linked list is itself broken, Rust can't help you either.

So I still don't see a causal relationship. Is it because I'm drunk?