Slow loris is I/O based, so it’s easy to abort. The rest will follow from that. Even if you piped your request stream into synchronous blocking io::Read adapter for use with Serde (which IMHO is pointless), the adapter will see an error due to its channel dropping, and bail out immediately.

Native busy-looping or deadlocked threads are tricky to kill safely, but that’s a general problem with threads in non-interpreted languages. Not specific to Serde, not related to Slow loris.