Additional error for invalid gas (#10327) (#10328)

* Tag sensible place (ECHECH)

* Additional overflows checks.

Author: kirushik

ethcore/evm/src/interpreter/mod.rs

@@ -571,10 +571,10 @@ impl<Cost: CostType> Interpreter<Cost> {
 				let out_size = self.stack.pop_back();
 
 				// Add stipend (only CALL|CALLCODE when value > 0)
-				let call_gas = call_gas + value.map_or_else(|| Cost::from(0), |val| match val.is_zero() {
+				let call_gas = call_gas.overflow_add(value.map_or_else(|| Cost::from(0), |val| match val.is_zero() {
 					false => Cost::from(ext.schedule().call_stipend),
 					true => Cost::from(0),
-				});
+				})).0;
 
 				// Get sender & receive addresses, check if we have balance
 				let (sender_address, receive_address, has_balance, call_type) = match instruction {

ethcore/light/src/transaction_queue.rs

@@ -95,7 +95,7 @@ impl AccountTransactions {
 	}
 
 	fn next_nonce(&self) -> U256 {
-		self.current.last().map(|last| last.nonce + 1)
+		self.current.last().map(|last| last.nonce.saturating_add(1.into()))
 			.unwrap_or_else(|| *self.cur_nonce.value())
 	}
 
@@ -107,7 +107,7 @@ impl AccountTransactions {
 		while let Some(tx) = self.future.remove(&next_nonce) {
 			promoted.push(tx.hash);
 			self.current.push(tx);
-			next_nonce = next_nonce + 1;
+			next_nonce = next_nonce.saturating_add(1.into());
 		}
 
 		promoted

ethcore/src/executive.rs

@@ -312,7 +312,7 @@ impl<'a> CallCreateExecutive<'a> {
 		let prev_bal = state.balance(&params.address)?;
 		if let ActionValue::Transfer(val) = params.value {
 			state.sub_balance(&params.sender, &val, &mut substate.to_cleanup_mode(&schedule))?;
-			state.new_contract(&params.address, val + prev_bal, nonce_offset)?;
+			state.new_contract(&params.address, val.saturating_add(prev_bal), nonce_offset)?;
 		} else {
 			state.new_contract(&params.address, prev_bal, nonce_offset)?;
 		}
@@ -1103,9 +1103,13 @@ impl<'a, B: 'a + StateBackend> Executive<'a, B> {
 		let refunded = cmp::min(refunds_bound, (t.gas - gas_left_prerefund) >> 1);
 		let gas_left = gas_left_prerefund + refunded;
 
-		let gas_used = t.gas - gas_left;
-		let refund_value = gas_left * t.gas_price;
-		let fees_value = gas_used * t.gas_price;
+		let gas_used = t.gas.saturating_sub(gas_left);
+		let (refund_value, overflow_1) = gas_left.overflowing_mul(t.gas_price);
+		let (fees_value, overflow_2) = gas_used.overflowing_mul(t.gas_price);
+		if overflow_1 || overflow_2 {
+			return Err(ExecutionError::TransactionMalformed("U256 Overflow".to_string()));
+		}
+
 
 		trace!("exec::finalize: t.gas={}, sstore_refunds={}, suicide_refunds={}, refunds_bound={}, gas_left_prerefund={}, refunded={}, gas_left={}, gas_used={}, refund_value={}, fees_value={}\n",
 			t.gas, sstore_refunds, suicide_refunds, refunds_bound, gas_left_prerefund, refunded, gas_left, gas_used, refund_value, fees_value);
@@ -1123,7 +1127,7 @@ impl<'a, B: 'a + StateBackend> Executive<'a, B> {
 		}
 
 		// perform garbage-collection
-		let min_balance = if schedule.kill_dust != CleanDustMode::Off { Some(U256::from(schedule.tx_gas) * t.gas_price) } else { None };
+		let min_balance = if schedule.kill_dust != CleanDustMode::Off { Some(U256::from(schedule.tx_gas).overflowing_mul(t.gas_price).0) } else { None };
 		self.state.kill_garbage(&substate.touched, schedule.kill_empty, &min_balance, schedule.kill_dust == CleanDustMode::WithCodeAndStorage)?;
 
 		match result {

ethcore/src/state/account.rs

@@ -466,12 +466,12 @@ impl Account {
 
 	/// Increment the nonce of the account by one.
 	pub fn inc_nonce(&mut self) {
-		self.nonce = self.nonce + U256::from(1u8);
+		self.nonce = self.nonce.saturating_add(U256::from(1u8));
 	}
 
 	/// Increase account balance.
 	pub fn add_balance(&mut self, x: &U256) {
-		self.balance = self.balance + *x;
+		self.balance = self.balance.saturating_add(*x);
 	}
 
 	/// Decrease account balance.

ethcore/src/state/mod.rs

@@ -500,7 +500,12 @@ impl<B: Backend> State<B> {
 	/// it will have its code reset, ready for `init_code()`.
 	pub fn new_contract(&mut self, contract: &Address, balance: U256, nonce_offset: U256) -> TrieResult<()> {
 		let original_storage_root = self.original_storage_root(contract)?;
-		self.insert_cache(contract, AccountEntry::new_dirty(Some(Account::new_contract(balance, self.account_start_nonce + nonce_offset, original_storage_root))));
+		let (nonce, overflow) = self.account_start_nonce.overflowing_add(nonce_offset);
+		if overflow {
+			return Err(Box::new(TrieError::DecoderError(H256::from(contract),
+				rlp::DecoderError::Custom("Nonce overflow".into()))));
+		}
+		self.insert_cache(contract, AccountEntry::new_dirty(Some(Account::new_contract(balance, nonce, original_storage_root))));
 		Ok(())
 	}
 

miner/src/pool/queue.rs

@@ -474,7 +474,7 @@ impl TransactionQueue {
 
 		self.pool.read().pending_from_sender(state_readiness, address)
 			.last()
-			.map(|tx| tx.signed().nonce + 1)
+			.map(|tx| tx.signed().nonce.saturating_add(U256::from(1)))
 	}
 
 	/// Retrieve a transaction from the pool.

miner/src/pool/ready.rs

@@ -95,7 +95,7 @@ impl<C: NonceClient> txpool::Ready<VerifiedTransaction> for State<C> {
 			},
 			cmp::Ordering::Less => txpool::Readiness::Stale,
 			cmp::Ordering::Equal => {
-				*nonce = *nonce + 1;
+				*nonce = nonce.saturating_add(U256::from(1));
 				txpool::Readiness::Ready
 			},
 		}
@@ -159,7 +159,7 @@ impl<C: Fn(&Address) -> Option<U256>> txpool::Ready<VerifiedTransaction> for Opt
 			cmp::Ordering::Greater => txpool::Readiness::Future,
 			cmp::Ordering::Less => txpool::Readiness::Stale,
 			cmp::Ordering::Equal => {
-				*nonce = *nonce + 1;
+				*nonce = nonce.saturating_add(U256::from(1));
 				txpool::Readiness::Ready
 			},
 		}

miner/src/pool/verifier.rs

@@ -283,7 +283,19 @@ impl<C: Client> txpool::Verifier<Transaction> for Verifier<C, ::pool::scoring::N
 			}
 		}
 
-		let cost = transaction.value + transaction.gas_price * transaction.gas;
+		let (full_gas_price, overflow_1) = transaction.gas_price.overflowing_mul(transaction.gas);
+		let (cost, overflow_2) = transaction.value.overflowing_add(full_gas_price);
+		if overflow_1 || overflow_2 {
+			trace!(
+				target: "txqueue",
+				"[{:?}] Rejected tx, price overflow",
+				hash
+			);
+			bail!(transaction::Error::InsufficientBalance {
+				cost: U256::max_value(),
+				balance: account_details.balance,
+			});
+		}
 		if account_details.balance < cost {
 			debug!(
 				target: "txqueue",