fix(driver): fix a blob decoding issue (#629)

Author: mask-pp

driver/chain_syncer/calldata/syncer.go

@@ -236,7 +236,12 @@ func (s *Syncer) onBlockProposed(
 	}
 	txListBytes, err := txListDecoder.Fetch(ctx, tx, &event.Meta)
 	if err != nil {
-		return fmt.Errorf("failed to decode tx list: %w", err)
+		if errors.Is(err, rpc.ErrBlobInvalid) {
+			log.Info("Invalid blob detected", "blockID", event.BlockId)
+			txListBytes = []byte{}
+		} else {
+			return fmt.Errorf("failed to decode tx list: %w", err)
+		}
 	}
 
 	l1Origin := &rawdb.L1Origin{

pkg/rpc/tx_blob.go

@@ -17,7 +17,7 @@ var (
 )
 
 var (
-	errBlobInvalid = errors.New("invalid blob encoding")
+	ErrBlobInvalid = errors.New("invalid blob encoding")
 )
 
 // TransactBlobTx creates, signs and then sends blob transactions.
@@ -148,10 +148,13 @@ func encode(origin []byte) []byte {
 	return res
 }
 
-func decode(data []byte) []byte {
+func decode(data []byte) ([]byte, error) {
 	blobLen := new(big.Int).SetBytes(data[:preLenBlob])
 	var lenBytes = blobLen.Uint64()
-	return data[preLenBlob:lenBytes]
+	if int(lenBytes) > len(data) {
+		return nil, ErrBlobInvalid
+	}
+	return data[preLenBlob:lenBytes], nil
 }
 
 // EncodeBlobs encodes bytes into a EIP-4844 blob.
@@ -172,13 +175,15 @@ func EncodeBlobs(origin []byte) []kzg4844.Blob {
 }
 
 // DecodeBlob decodes the given blob data.
-func DecodeBlob(blob []byte) ([]byte, error) {
+func DecodeBlob(blob []byte) (res []byte, err error) {
 	if len(blob) != BlobBytes {
-		return nil, errBlobInvalid
+		return nil, ErrBlobInvalid
+	}
+	blob, err = decode(blob)
+	if err != nil {
+		return nil, err
 	}
-	blob = decode(blob)
 
-	var res []byte
 	for ; len(blob) >= 32; blob = blob[32:] {
 		data := [31]byte{}
 		copy(data[:], blob[1:])