core, eth/downloader, params: validate blob tx bodies (#27392)

eth/downloader/queue.go

@@ -801,7 +801,23 @@ func (q *queue) DeliverBodies(id string, txLists [][]*types.Transaction, txListH
 		// and zero before the Cancun hardfork
 		var blobs int
 		for _, tx := range txLists[index] {
+			// Count the number of blobs to validate against the header's dataGasUsed
 			blobs += len(tx.BlobHashes())
+
+			// Validate the data blobs individually too
+			if tx.Type() == types.BlobTxType {
+				if tx.To() == nil {
+					return errInvalidBody // TODO(karalabe): Why not make the field non-nil-able
+				}
+				if len(tx.BlobHashes()) == 0 {
+					return errInvalidBody
+				}
+				for _, hash := range tx.BlobHashes() {
+					if hash[0] != params.BlobTxHashVersion {
+						return errInvalidBody
+					}
+				}
+			}
 		}
 		if header.DataGasUsed != nil {
 			if want := *header.DataGasUsed / params.BlobTxDataGasPerBlob; uint64(blobs) != want { // div because the header is surely good vs the body might be bloated