Denial of service in geth

@@ -190,8 +190,12 @@ func (z *Int) AddOverflow(x, y *Int) bool {
 	return carry != 0
 }
 
-// AddMod sets z to the sum ( x+y ) mod m, and returns z
+// AddMod sets z to the sum ( x+y ) mod m, and returns z.
+// If m == 0, z is set to 0 (OBS: differs from the big.Int)
 func (z *Int) AddMod(x, y, m *Int) *Int {
+	if m.IsZero() {
+		return z.Clear()
+	}
 	if z == m { // z is an alias for m  // TODO: Understand why needed and add tests for all "division" methods.
 		m = m.Clone()
 	}
@@ -567,8 +571,12 @@ func (z *Int) SMod(x, y *Int) *Int {
 }
 
 // MulMod calculates the modulo-m multiplication of x and y and
-// returns z
+// returns z.
+// If m == 0, z is set to 0 (OBS: differs from the big.Int)
 func (z *Int) MulMod(x, y, m *Int) *Int {
+	if x.IsZero() || y.IsZero() || m.IsZero() {
+		return z.Clear()
+	}
 	p := umul(x, y)
 	var (
 		pl Int

@@ -74,6 +74,10 @@ var (
 
 	// A collection of interesting input values for ternary operators (addmod, mulmod).
 	ternTestCases = [][3]string{
+		{"0", "0", "0"},
+		{"1", "0", "0"},
+		{"1", "1", "0"},
+		{"0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffd", "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe", "0"},
 		{"0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffd", "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
 		{"0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffd", "3", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
 		{"0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
@@ -920,9 +924,22 @@ func TestTernOp(t *testing.T) {
 			}
 		}
 	}
-
-	t.Run("AddMod", func(t *testing.T) { proc(t, (*Int).AddMod, addMod) })
-	t.Run("MulMod", func(t *testing.T) { proc(t, (*Int).MulMod, mulMod) })
+	t.Run("AddMod", func(t *testing.T) {
+		proc(t, (*Int).AddMod, func(z, x, y, m *big.Int) *big.Int {
+			if m.Sign() == 0 {
+				return z.SetUint64(0)
+			}
+			return addMod(z, x, y, m)
+		})
+	})
+	t.Run("MulMod", func(t *testing.T) {
+		proc(t, (*Int).MulMod, func(z, x, y, m *big.Int) *big.Int {
+			if m.Sign() == 0 {
+				return z.SetUint64(0)
+			}
+			return mulMod(z, x, y, m)
+		})
+	})
 }
 
 func TestCmpOp(t *testing.T) {

@@ -20,9 +20,9 @@ func (l Log) MarshalJSON() ([]byte, error) {
 		Data        hexutil.Bytes  `json:"data" gencodec:"required"`
 		BlockNumber hexutil.Uint64 `json:"blockNumber"`
 		TxHash      common.Hash    `json:"transactionHash" gencodec:"required"`
-		TxIndex     hexutil.Uint   `json:"transactionIndex" gencodec:"required"`
+		TxIndex     hexutil.Uint   `json:"transactionIndex"`
 		BlockHash   common.Hash    `json:"blockHash"`
-		Index       hexutil.Uint   `json:"logIndex" gencodec:"required"`
+		Index       hexutil.Uint   `json:"logIndex"`
 		Removed     bool           `json:"removed"`
 	}
 	var enc Log
@@ -46,9 +46,9 @@ func (l *Log) UnmarshalJSON(input []byte) error {
 		Data        *hexutil.Bytes  `json:"data" gencodec:"required"`
 		BlockNumber *hexutil.Uint64 `json:"blockNumber"`
 		TxHash      *common.Hash    `json:"transactionHash" gencodec:"required"`
-		TxIndex     *hexutil.Uint   `json:"transactionIndex" gencodec:"required"`
+		TxIndex     *hexutil.Uint   `json:"transactionIndex"`
 		BlockHash   *common.Hash    `json:"blockHash"`
-		Index       *hexutil.Uint   `json:"logIndex" gencodec:"required"`
+		Index       *hexutil.Uint   `json:"logIndex"`
 		Removed     *bool           `json:"removed"`
 	}
 	var dec Log
@@ -74,17 +74,15 @@ func (l *Log) UnmarshalJSON(input []byte) error {
 		return errors.New("missing required field 'transactionHash' for Log")
 	}
 	l.TxHash = *dec.TxHash
-	if dec.TxIndex == nil {
-		return errors.New("missing required field 'transactionIndex' for Log")
+	if dec.TxIndex != nil {
+		l.TxIndex = uint(*dec.TxIndex)
 	}
-	l.TxIndex = uint(*dec.TxIndex)
 	if dec.BlockHash != nil {
 		l.BlockHash = *dec.BlockHash
 	}
-	if dec.Index == nil {
-		return errors.New("missing required field 'logIndex' for Log")
+	if dec.Index != nil {
+		l.Index = uint(*dec.Index)
 	}
-	l.Index = uint(*dec.Index)
 	if dec.Removed != nil {
 		l.Removed = *dec.Removed
 	}

@@ -44,11 +44,11 @@ type Log struct {
 	// hash of the transaction
 	TxHash common.Hash `json:"transactionHash" gencodec:"required"`
 	// index of the transaction in the block
-	TxIndex uint `json:"transactionIndex" gencodec:"required"`
+	TxIndex uint `json:"transactionIndex"`
 	// hash of the block in which the transaction was included
 	BlockHash common.Hash `json:"blockHash"`
 	// index of the log in the block
-	Index uint `json:"logIndex" gencodec:"required"`
+	Index uint `json:"logIndex"`
 
 	// The Removed field is true if this log was reverted due to a chain reorganisation.
 	// You must pay attention to this field if you receive logs through a filter query.

@@ -282,6 +282,10 @@ func toBlockNumArg(number *big.Int) string {
 	if number == nil {
 		return "latest"
 	}
+	pending := big.NewInt(-1)
+	if number.Cmp(pending) == 0 {
+		return "pending"
+	}
 	return hexutil.EncodeBig(number)
 }
 

@@ -97,6 +97,22 @@ func TestToFilterArg(t *testing.T) {
 			},
 			nil,
 		},
+		{
+			"with negative fromBlock and negative toBlock",
+			ethereum.FilterQuery{
+				Addresses: addresses,
+				FromBlock: big.NewInt(-1),
+				ToBlock:   big.NewInt(-1),
+				Topics:    [][]common.Hash{},
+			},
+			map[string]interface{}{
+				"address":   addresses,
+				"fromBlock": "pending",
+				"toBlock":   "pending",
+				"topics":    [][]common.Hash{},
+			},
+			nil,
+		},
 		{
 			"with blockhash",
 			ethereum.FilterQuery{