rust: add proper overflow check

Author: axic

bindings/rust/src/lib.rs

@@ -299,7 +299,7 @@ impl Instance {
         let offset = offset as usize;
         let memory_size = self.memory_size();
         // Empty slices are allowed, but ensure both starting and ending offsets are valid.
-        if memory_size == 0 || offset > memory_size || (offset + size) > memory_size {
+        if memory_size == 0 || offset.checked_add(size).is_none() || (offset + size) > memory_size {
             return Err(());
         }
         debug_assert!(memory_size != 0);