error: Undefined Behavior: out-of-bounds pointer use: ALLOC has size 2, so pointer to 4 bytes starting at offset 0 is out-of-bounds
  --> RUSTLIB/alloc/src/boxed.rs:LL:CC
   |
LL |         Box(unsafe { Unique::new_unchecked(raw) }, alloc)
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: ALLOC has size 2, so pointer to 4 bytes starting at offset 0 is out-of-bounds
   |
   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
   = note: BACKTRACE:
   = note: inside `std::boxed::Box::<u32>::from_raw_in` at RUSTLIB/alloc/src/boxed.rs:LL:CC
   = note: inside `std::boxed::Box::<u32>::from_raw` at RUSTLIB/alloc/src/boxed.rs:LL:CC
note: inside `main` at $DIR/issue-miri-1050-1.rs:LL:CC
  --> $DIR/issue-miri-1050-1.rs:LL:CC
   |
LL |         drop(Box::from_raw(ptr as *mut u32));
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error