Fix memory initialization when offset is negative

crates/environ/src/module_environ.rs

@@ -607,7 +607,7 @@ impl<'a, 'data> ModuleEnvironment<'a, 'data> {
  let memory_index = MemoryIndex::from_u32(memory_index);
  let mut offset_expr_reader = offset_expr.get_binary_reader();
  let (base, offset) = match offset_expr_reader.read_operator()? {
- Operator::I32Const { value } => (None, value as u64),
+ Operator::I32Const { value } => (None, (value as u32).into()),
  Operator::I64Const { value } => (None, value as u64),
  Operator::GlobalGet { global_index } => {
  (Some(GlobalIndex::from_u32(global_index)), 0)

tests/all/memory.rs

@@ -642,3 +642,21 @@ fn shared_memory_wait_notify() -> Result<()> {
 
  Ok(())
 }
+
+#[test]
+#[cfg_attr(miri, ignore)]
+fn init_with_negative_segment() -> Result<()> {
+ let engine = Engine::default();
+ let module = Module::new(
+ &engine,
+ r#"
+ (module
+ (memory 65536)
+ (data (i32.const 0x8000_0000) "x")
+ )
+ "#,
+ )?;
+ let mut store = Store::new(&engine, ());
+ Instance::new(&mut store, &module, &[])?;
+ Ok(())
+}