v1.9: Only examine explicit tx accounts for rent state (#22442)

* Add failing test

* Fix: only examine accounts explicitly included in a tx

runtime/src/bank.rs

@@ -15910,4 +15910,46 @@ pub(crate) mod tests {
         let result = bank.process_transaction(&tx);
         assert!(result.is_ok());
     }
+
+    #[test]
+    fn test_rent_state_list_len() {
+        let GenesisConfigInfo {
+            mut genesis_config,
+            mint_keypair,
+            ..
+        } = create_genesis_config_with_leader(sol_to_lamports(100.), &Pubkey::new_unique(), 42);
+        genesis_config.rent = Rent::default();
+        // Activate features, including require_rent_exempt_accounts
+        activate_all_features(&mut genesis_config);
+
+        let bank = Bank::new_for_tests(&genesis_config);
+        let recipient = Pubkey::new_unique();
+        let tx = system_transaction::transfer(
+            &mint_keypair,
+            &recipient,
+            sol_to_lamports(1.),
+            bank.last_blockhash(),
+        );
+        let num_accounts = tx.message().account_keys.len();
+        let sanitized_tx = SanitizedTransaction::try_from_legacy_transaction(tx).unwrap();
+        let mut error_counters = ErrorCounters::default();
+        let loaded_txs = bank.rc.accounts.load_accounts(
+            &bank.ancestors,
+            &[sanitized_tx.clone()],
+            vec![(Ok(()), None)],
+            &bank.blockhash_queue.read().unwrap(),
+            &mut error_counters,
+            &bank.rent_collector,
+            &bank.feature_set,
+        );
+
+        let account_refcells =
+            Bank::accounts_to_refcells(&mut loaded_txs[0].0.as_ref().unwrap().accounts.clone());
+
+        assert_eq!(
+            bank.get_transaction_account_state_info(&account_refcells, sanitized_tx.message())
+                .len(),
+            num_accounts,
+        );
+    }
 }

runtime/src/bank/transaction_account_state_info.rs

@@ -22,6 +22,7 @@ impl Bank {
     ) -> Vec<TransactionAccountStateInfo> {
         transaction_account_refcells
             .iter()
+            .take(message.account_keys_len())
             .enumerate()
             .map(|(i, (_pubkey, account_refcell))| {
                 let account = account_refcell.borrow();