Reject the block if the block hash changes in the Append

core/error.go

@@ -73,6 +73,9 @@ var (
 
 	// ErrPendingHeaderNotInCache is returned when a coord gives an update but the slice has not yet created the referenced ph
 	ErrPendingHeaderNotInCache = errors.New("no pending header found in cache")
+
+	// ErrBlockHashChanged is returned when the block is mutated in the Append
+	ErrBlockHashChanged = errors.New("rejecting the block because block hash changed during append")
 )
 
 // List of evm-call-message pre-checking errors. All state transition messages will

core/slice.go

@@ -141,6 +141,8 @@ func NewSlice(db ethdb.Database, config *Config, txConfig *TxPoolConfig, txLooku
 func (sl *Slice) Append(header *types.Header, domPendingHeader *types.Header, domTerminus common.Hash, domOrigin bool, newInboundEtxs types.Transactions) (types.Transactions, bool, bool, error) {
 	start := time.Now()
 
+	blockHash := header.Hash()
+
 	if header.Hash() == sl.config.GenesisHash {
 		return nil, false, false, nil
 	}
@@ -316,6 +318,15 @@ func (sl *Slice) Append(header *types.Header, domPendingHeader *types.Header, do
 		time9 = common.PrettyDuration(time.Since(start))
 
 	}
+
+	// If block hash at the beginning of the append is not the same as before
+	// modifying the phCache and Batch write we need to reject the block. This
+	// check can be removed after fixing the block hash mutation bug observed in
+	// testnet
+	if block.Hash() != blockHash {
+		return nil, false, false, ErrBlockHashChanged
+	}
+
 	sl.updatePhCache(pendingHeaderWithTermini, true, nil, subReorg, common.NodeLocation)
 
 	var updateDom bool