consensus/clique: add some missing checks (#22836)

consensus/clique/clique.go

@@ -20,6 +20,7 @@ package clique
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"math/big"
 	"math/rand"
 	"sync"
@@ -316,6 +317,16 @@ func (c *Clique) verifyHeader(chain consensus.ChainReader, header *types.Header,
 			return errInvalidDifficulty
 		}
 	}
+
+	// Verify that the gas limit is <= 2^63-1
+	if header.GasLimit > params.MaxGasLimit {
+		return fmt.Errorf("invalid gasLimit: have %v, max %v", header.GasLimit, params.MaxGasLimit)
+	}
+
+	// Verify that the gasUsed is <= gasLimit
+	if header.GasUsed > header.GasLimit {
+		return fmt.Errorf("invalid gasUsed: have %d, gasLimit %d", header.GasUsed, header.GasLimit)
+	}
 	// If all checks passed, validate any special fields for hard forks
 	if err := misc.VerifyForkHashes(chain.Config(), header, false); err != nil {
 		return err
@@ -347,6 +358,11 @@ func (c *Clique) verifyCascadingFields(chain consensus.ChainReader, header *type
 	if parent.Time.Uint64()+c.config.Period > header.Time.Uint64() {
 		return ErrInvalidTimestamp
 	}
+	// Verify that the gas limit remains within allowed bounds
+	if err := misc.VerifyGaslimit(parent.GasLimit, header.GasLimit); err != nil {
+		return err
+	}
+
 	// Retrieve the snapshot needed to verify this header and cache it
 	snap, err := c.snapshot(chain, number-1, header.ParentHash, parents)
 	if err != nil {

consensus/misc/gaslimit.go

@@ -0,0 +1,41 @@
+// Copyright 2021 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package misc
+
+import (
+	"fmt"
+
+	"github.com/XinFinOrg/XDPoSChain/params"
+)
+
+// VerifyGaslimit verifies the header gas limit according increase/decrease
+// in relation to the parent gas limit.
+func VerifyGaslimit(parentGasLimit, headerGasLimit uint64) error {
+	// Verify that the gas limit remains within allowed bounds
+	diff := int64(parentGasLimit) - int64(headerGasLimit)
+	if diff < 0 {
+		diff *= -1
+	}
+	limit := parentGasLimit / params.GasLimitBoundDivisor
+	if uint64(diff) >= limit {
+		return fmt.Errorf("invalid gas limit: have %d, want %d +-= %d", headerGasLimit, parentGasLimit, limit-1)
+	}
+	if headerGasLimit < params.MinGasLimit {
+		return fmt.Errorf("invalid gas limit below %d", params.MinGasLimit)
+	}
+	return nil
+}

params/protocol_params.go

@@ -25,6 +25,7 @@ var (
 const (
 	GasLimitBoundDivisor uint64 = 1024    // The bound divisor of the gas limit, used in update calculations.
 	MinGasLimit          uint64 = 5000    // Minimum the gas limit may ever be.
+	MaxGasLimit          uint64 = 0x7fffffffffffffff // Maximum the gas limit (2^63-1).
 	GenesisGasLimit      uint64 = 4712388 // Gas limit of the Genesis block.
 	XDCGenesisGasLimit   uint64 = 84000000