Fix ReturnData (#1683)

mythril/laser/ethereum/instructions.py

@@ -1838,7 +1838,7 @@ class Instruction:
             global_state.mstate.pop(3)
         if global_state.last_return_data:
             return_val = symbol_factory.BitVecVal(
-                int(global_state.last_return_data, 16), 256
+                int(global_state.last_return_data.return_data, 16), 256
             )
         else:
             return_val = symbol_factory.BitVecVal(0, 256)

mythril/laser/ethereum/transaction/transaction_models.py

@@ -8,6 +8,7 @@ from mythril.support.support_utils import Singleton
 from mythril.laser.ethereum.state.calldata import ConcreteCalldata
 from mythril.laser.ethereum.state.account import Account
 from mythril.laser.ethereum.state.calldata import BaseCalldata, SymbolicCalldata
+from mythril.laser.ethereum.state.return_data import ReturnData
 from mythril.laser.ethereum.state.environment import Environment
 from mythril.laser.ethereum.state.global_state import GlobalState
 from mythril.laser.ethereum.state.world_state import WorldState
@@ -273,9 +274,8 @@ class ContractCreationTransaction(BaseTransaction):
         global_state.environment.active_account.code.assign_bytecode(
             tuple(return_data.return_data)
         )
-        self.return_data = str(
+        return_data = str(hex(global_state.environment.active_account.address.value))
-            hex(global_state.environment.active_account.address.value)
+        self.return_data = ReturnData(return_data, len(return_data) // 2)
-        )
         assert global_state.environment.active_account.code.instruction_list != []
 
         raise TransactionEndSignal(global_state, revert=revert)

solidity_examples/killbilly.sol

@@ -0,0 +1,24 @@
+pragma solidity 0.5.7;
+
+contract KillBilly {
+	bool public is_killable;
+	mapping (address => bool) public approved_killers;
+
+	constructor() public {
+		is_killable = false;
+	}
+
+	function killerize(address addr) public {
+		approved_killers[addr] = true;
+	}
+
+	function activatekillability() public {
+		require(approved_killers[msg.sender] == true);
+		is_killable = true;
+	}
+
+	function commencekilling() public {
+	    require(is_killable);
+	 	selfdestruct(msg.sender);
+	}
+}