add max gas cap in eth_call

Author: thomas-nguy

x/evm/types/tx_args.go

@@ -133,20 +133,24 @@ func (args *TransactionArgs) ToMessage(globalGasCap uint64, baseFee *big.Int) (*
 		return nil, errors.New("both gasPrice and (maxFeePerGas or maxPriorityFeePerGas) specified")
 	}
 
+	// Ethereum block size is ~36000000
+	MaxGasCap := uint64(100000000)
+
 	// Set sender address or use zero address if none specified.
 	addr := args.GetFrom()
 
 	// Set default gas & gas price if none were set
 	gas := globalGasCap
 	if gas == 0 {
-		gas = uint64(math.MaxUint64 / 2)
+		gas = MaxGasCap
 	}
 	if args.Gas != nil {
 		gas = uint64(*args.Gas)
 	}
 	if globalGasCap != 0 && globalGasCap < gas {
 		gas = globalGasCap
 	}
+
 	var (
 		gasPrice  *big.Int
 		gasFeeCap *big.Int
@@ -197,6 +201,11 @@ func (args *TransactionArgs) ToMessage(globalGasCap uint64, baseFee *big.Int) (*
 		nonce = uint64(*args.Nonce)
 	}
 
+	// Limit gas cap to avoid DOS during simulation
+	if gas > MaxGasCap {
+		gas = MaxGasCap
+	}
+
 	msg := &core.Message{
 		From:              addr,
 		To:                args.To,

x/evm/types/tx_args_test.go

@@ -2,6 +2,7 @@ package types
 
 import (
 	"fmt"
+	"math"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -286,3 +287,45 @@ func (suite *TxDataTestSuite) TestGetData() {
 		suite.Require().Equal(retrievedData, tc.expectedOutput)
 	}
 }
+
+func (suite *TxDataTestSuite) TestMaxGasCap() {
+	testCases := []struct {
+		name           string
+		globalGasCap   uint64
+		txArgs         TransactionArgs
+		expectedOutput uint64
+	}{
+		{
+			"globalGasCap is below limit",
+			25000000,
+			TransactionArgs{
+				Gas:   nil,
+				Input: nil,
+			},
+			25000000,
+		},
+		{
+			"globalGasCap is above limit",
+			math.MaxInt64,
+			TransactionArgs{
+				Gas:   nil,
+				Input: nil,
+			},
+			100000000,
+		},
+		{
+			"globalGasCap is zero",
+			0,
+			TransactionArgs{
+				Gas:   nil,
+				Input: nil,
+			},
+			100000000,
+		},
+	}
+	for _, tc := range testCases {
+		res, err := tc.txArgs.ToMessage(tc.globalGasCap, nil)
+		suite.Require().Nil(err)
+		suite.Require().Equal(res.GasLimit, tc.expectedOutput)
+	}
+}