Update verify policy (#18459)

runtime/src/message_processor.rs

@@ -180,7 +180,7 @@ impl PreAccount {
             }
             if !is_writable // line coverage used to get branch coverage
                 || pre.executable()
-                || program_id != pre.owner()
+                || program_id != post.owner()
             {
                 return Err(InstructionError::ExecutableModified);
             }
@@ -1787,6 +1787,21 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_verify_account_changes_owner_executable() {
+        let alice_program_id = solana_sdk::pubkey::new_rand();
+        let bob_program_id = solana_sdk::pubkey::new_rand();
+
+        assert_eq!(
+            Change::new(&alice_program_id, &alice_program_id)
+                .owner(&bob_program_id)
+                .executable(false, true)
+                .verify(),
+            Err(InstructionError::ExecutableModified),
+            "Program should not be able to change owner and executable at the same time"
+        );
+    }
+
     #[test]
     fn test_process_message_readonly_handling() {
         #[derive(Serialize, Deserialize)]