[serializer] Fixing issues in serialization

move-language · Sep 23, 2022 · 566ace5 · 566ace5
1 parent 0fe2e6c
commit 566ace5
Showing 1 changed file with 16 additions and 2 deletions.
diff --git a/language/move-bytecode-verifier/src/stack_usage_verifier.rs b/language/move-bytecode-verifier/src/stack_usage_verifier.rs
@@ -56,8 +56,22 @@ impl<'a> StackUsageVerifier<'a> {
                         .at_code_offset(self.current_function(), block_start),
                 );
             }
-            stack_size_increment -= num_pops;
-            stack_size_increment += num_pushes;
+            if let Some(new_incr) = u64::checked_sub(stack_size_increment, num_pops) {
+                stack_size_increment = new_incr
+            } else {
+                return Err(
+                    PartialVMError::new(StatusCode::NEGATIVE_STACK_SIZE_WITHIN_BLOCK)
+                        .at_code_offset(self.current_function(), block_start),
+                );
+            };
+            if let Some(new_incr) = u64::checked_add(stack_size_increment, num_pushes) {
+                stack_size_increment = new_incr
+            } else {
+                return Err(
+                    PartialVMError::new(StatusCode::POSITIVE_STACK_SIZE_AT_BLOCK_END)
+                        .at_code_offset(self.current_function(), block_start),
+                );
+            };
         }
 
         if stack_size_increment == 0 {