When does the memory pointed to by a SpanByte get released?

[xFleury]

I couldn't find an answer to this in any of the documentation. If I have a KV store defined as
FasterKV<ulong, SpanByte> storage;
and I make a session
session = storage.For(new SimpleFunctions<ulong, SpanByte>()).NewSession<SimpleFunctions<ulong, SpanByte>>();
and in that session I read to a spanByte
session.Read(key, out spanByte);

That spanByte has a pointer to some block of memory somewhere. Am I right to assume that that pointer is valid for the entire duration of the session, but only the duration of the session?

Similarly, if I call session.Write and pass it a SpanByte, do I need to ensure that the pointer I give it is also valid for the entire duration of the session? Or do I only need to keep it valid for the duration of the call to the Write?