You can dereference null pointers in Rust, it's also easy to make null pointers. The thing is I'm not surprised you didn't realise this is possible because you would never actually do this in Rust since it's obviously a bad idea.

  let p: *const i32 = std::ptr::null();  // Pointer to a signed 32-bit integer, but it's null
  unsafe { some_local = *p };            // Dereferencing the null pointer, bang

If we instead use references they're nicer to work with, don't need unsafe, perform the same, and are never null. So obviously that's what real Rust programmers almost always do.

Of course it’s possible. I am well aware it’s possible. You can also just call into a C library that hands you a null pointer. Further, it’s wholly possible to invalidate every single one of Rust’s safety guarantees if you try hard enough.

In practice I have never encountered a null pointer in Rust. Most Rust programmers have never encountered a null pointer. For most non-FFI practical purposes you can act as if they don’t exist.