Fix issues related to CREATE2 collisions (#1050)

* Fix issues related to CREATE2 collisions

* Add error functions

evm/src/cpu/kernel/asm/core/create.asm

@@ -81,12 +81,6 @@ global create_common:
 
     %checkpoint
 
-    // Create the new contract account in the state trie.
-    DUP1
-    // stack: address, address, value, code_offset, code_len, kexit_info
-    %create_contract_account
-    // stack: status, address, value, code_offset, code_len, kexit_info
-    %jumpi(fault_exception)
     // stack: address, value, code_offset, code_len, kexit_info
     DUP2 DUP2 %address %transfer_eth %jumpi(panic) // We checked the balance above, so this should never happen.
     DUP2 DUP2 %address %journal_add_balance_transfer // Add journal entry for the balance transfer.
@@ -127,6 +121,12 @@ run_constructor:
     %set_new_ctx_gas_limit
     // stack: new_ctx, address, kexit_info
 
+    // Create the new contract account in the state trie.
+    DUP2
+    %create_contract_account
+    // stack: status, new_ctx, address, kexit_info
+    %jumpi(create_collision)
+
     %enter_new_ctx
     // (Old context) stack: new_ctx, address, kexit_info
 
@@ -141,13 +141,13 @@ after_constructor:
     POP
 
     // EIP-3541: Reject new contract code starting with the 0xEF byte
-    PUSH 0 %mload_current(@SEGMENT_RETURNDATA) %eq_const(0xEF) %jumpi(fault_exception)
+    PUSH 0 %mload_current(@SEGMENT_RETURNDATA) %eq_const(0xEF) %jumpi(create_first_byte_ef)
 
     // Charge gas for the code size.
     // stack: leftover_gas, success, address, kexit_info
     %returndatasize // Size of the code.
     // stack: code_size, leftover_gas, success, address, kexit_info
-    DUP1 %gt_const(@MAX_CODE_SIZE) %jumpi(fault_exception)
+    DUP1 %gt_const(@MAX_CODE_SIZE) %jumpi(create_code_too_large)
     // stack: code_size, leftover_gas, success, address, kexit_info
     %mul_const(@GAS_CODEDEPOSIT)
     // stack: code_size_cost, leftover_gas, success, address, kexit_info
@@ -189,14 +189,30 @@ after_constructor_failed:
     %jump(after_constructor_contd)
 
 create_insufficient_balance:
-    // stack: address, value, code_offset, code_len, kexit_info
+    %revert_checkpoint
     %stack (address, value, code_offset, code_len, kexit_info) -> (kexit_info, 0)
     EXIT_KERNEL
 
 nonce_overflow:
+    %revert_checkpoint
     %stack (sender, address, value, code_offset, code_len, kexit_info) -> (kexit_info, 0)
     EXIT_KERNEL
 
+create_collision:
+    %revert_checkpoint
+    %stack (new_ctx, address, kexit_info) -> (kexit_info, 0)
+    EXIT_KERNEL
+
+create_first_byte_ef:
+    %revert_checkpoint
+    %stack (leftover_gas, success, address, kexit_info) -> (kexit_info, 0)
+    EXIT_KERNEL
+
+create_code_too_large:
+    %revert_checkpoint
+    %stack (code_size, leftover_gas, success, address, kexit_info) -> (kexit_info, 0)
+    EXIT_KERNEL
+
 %macro set_codehash
     %stack (addr, codehash) -> (addr, codehash, %%after)
     %jump(set_codehash)

evm/src/cpu/kernel/asm/core/create_contract_account.asm

@@ -1,5 +1,5 @@
 // Create a smart contract account with the given address and the given endowment value.
-// Pre stack: value, address
+// Pre stack: address
 // Post stack: status
 %macro create_contract_account
     // stack: address
@@ -10,12 +10,19 @@
     // so we can skip ahead, setting existing_balance = existing_account_ptr = 0.
     DUP1 ISZERO %jumpi(%%add_account)
 
+    // Check that the nonce is 0.
     // stack: existing_account_ptr, address
     DUP1 %mload_trie_data // nonce = account[0]
     // stack: nonce, existing_account_ptr, address
-    %jumpi(%%error_nonzero_nonce)
+    %jumpi(%%error_collision)
     // stack: existing_account_ptr, address
-    %increment %mload_trie_data // balance = account[1]
+    // Check that the code is empty.
+    %add_const(3)
+    // stack: existing_codehash_ptr, address
+    DUP1 %mload_trie_data // nonce = account[0]
+    %eq_const(@EMPTY_STRING_HASH) ISZERO %jumpi(%%error_collision)
+    // stack: existing_codehash_ptr, address
+    %sub_const(2) %mload_trie_data // balance = account[1]
     %jump(%%do_insert)
 
 %%add_account:
@@ -44,10 +51,10 @@
     PUSH 0 // success
     %jump(%%end)
 
-// If the nonce is nonzero, that means a contract has already been deployed to this address.
+// If the nonce is nonzero or the code is non-empty, that means a contract has already been deployed to this address.
 // (This should be impossible with contract creation transactions or CREATE, but possible with CREATE2.)
 // So we return 1 to indicate an error.
-%%error_nonzero_nonce:
+%%error_collision:
     %stack (existing_account_ptr, address) -> (1)
 
 %%end:

evm/src/cpu/kernel/asm/core/transfer.asm

@@ -87,6 +87,7 @@ global add_eth_new_account:
     POP
     // stack: addr, amount, retdest
     DUP2 ISZERO %jumpi(add_eth_new_account_zero)
+    DUP1 %journal_add_account_created
     %get_trie_data_size // pointer to new account we're about to create
     // stack: new_account_ptr, addr, amount, retdest
     SWAP2