Fix nil batchFetcher dereference in FillInBatchGasFields

arbnode/delayed.go

@@ -239,9 +239,11 @@ func (b *DelayedBridge) logsToDeliveredMessages(ctx context.Context, logs []type
 			},
 			ParentChainBlockNumber: parsedLog.Raw.BlockNumber,
 		}
-		err := msg.Message.FillInBatchGasFieldsWithParentBlock(batchFetcher, msg.ParentChainBlockNumber)
-		if err != nil {
-			return nil, err
+		if batchFetcher != nil {
+			err := msg.Message.FillInBatchGasFieldsWithParentBlock(batchFetcher, msg.ParentChainBlockNumber)
+			if err != nil {
+				return nil, err
+			}
 		}
 		messages = append(messages, msg)
 	}

arbnode/inbox_tracker.go

@@ -338,16 +338,15 @@ func (t *InboxTracker) legacyGetDelayedMessageAndAccumulator(ctx context.Context
 	}
 	var acc common.Hash
 	copy(acc[:], data[:32])
-	msg, err := arbostypes.ParseIncomingL1Message(bytes.NewReader(data[32:]), nil)
+	batchFetcher := func(batchNum uint64) ([]byte, error) {
+		data, _, err := t.txStreamer.inboxReader.GetSequencerMessageBytes(ctx, batchNum)
+		return data, err
+	}
+	msg, err := arbostypes.ParseIncomingL1Message(bytes.NewReader(data[32:]), batchFetcher)
 	if err != nil {
 		return nil, common.Hash{}, err
 	}
 
-	err = msg.FillInBatchGasFields(func(batchNum uint64) ([]byte, error) {
-		data, _, err := t.txStreamer.inboxReader.GetSequencerMessageBytes(ctx, batchNum)
-		return data, err
-	})
-
 	return msg, acc, err
 }
 

arbnode/transaction_streamer.go

@@ -382,7 +382,11 @@ func (s *TransactionStreamer) addMessagesAndReorg(batch ethdb.Batch, msgIdxOfFir
 					continue
 				}
 				msgBlockNum := new(big.Int).SetUint64(oldMessage.Message.Header.BlockNumber)
-				delayedInBlock, err := s.delayedBridge.LookupMessagesInRange(s.GetContext(), msgBlockNum, msgBlockNum, nil)
+				batchFetcher := func(batchNum uint64, parentChainBlockNumber uint64) ([]byte, error) {
+					data, _, err := s.inboxReader.GetSequencerMessageBytesForParentBlock(s.GetContext(), batchNum, parentChainBlockNumber)
+					return data, err
+				}
+				delayedInBlock, err := s.delayedBridge.LookupMessagesInRange(s.GetContext(), msgBlockNum, msgBlockNum, batchFetcher)
 				if err != nil {
 					log.Error("reorg-resequence: failed to serialize old delayed message from database", "err", err)
 					continue
@@ -516,7 +520,7 @@ func (s *TransactionStreamer) GetMessage(msgIdx arbutil.MessageIndex) (*arbostyp
 	}
 
 	if s.inboxReader != nil {
-		err = message.Message.FillInBatchGasFields(func(batchNum uint64) ([]byte, error) {
+		batchFetcher := func(batchNum uint64) ([]byte, error) {
 			ctx, err := s.GetContextSafe()
 			if err != nil {
 				return nil, err
@@ -533,7 +537,8 @@ func (s *TransactionStreamer) GetMessage(msgIdx arbutil.MessageIndex) (*arbostyp
 			}
 
 			return data, err
-		})
+		}
+		err = message.Message.FillInBatchGasFields(batchFetcher)
 		if err != nil {
 			return nil, err
 		}

arbos/arbostypes/incomingmessage.go

@@ -189,13 +189,20 @@ func LegacyCostForStats(stats *BatchDataStats) uint64 {
 }
 
 func (msg *L1IncomingMessage) FillInBatchGasFields(batchFetcher FallibleBatchFetcher) error {
-	return msg.FillInBatchGasFieldsWithParentBlock(FromFallibleBatchFetcher(batchFetcher), msg.Header.BlockNumber)
+	var fetcher FallibleBatchFetcherWithParentBlock
+	if batchFetcher != nil {
+		fetcher = FromFallibleBatchFetcher(batchFetcher)
+	}
+	return msg.FillInBatchGasFieldsWithParentBlock(fetcher, msg.Header.BlockNumber)
 }
 
 func (msg *L1IncomingMessage) FillInBatchGasFieldsWithParentBlock(batchFetcher FallibleBatchFetcherWithParentBlock, parentChainBlockNumber uint64) error {
-	if batchFetcher == nil || msg.Header.Kind != L1MessageType_BatchPostingReport {
+	if msg.Header.Kind != L1MessageType_BatchPostingReport {
 		return nil
 	}
+	if batchFetcher == nil {
+		return fmt.Errorf("batch fetcher is nil, cannot fill in batch gas fields for batch posting report (parentChainBlockNumber %d)", parentChainBlockNumber)
+	}
 	if msg.BatchDataStats != nil && msg.LegacyBatchGasCost != nil {
 		return nil
 	}
@@ -220,7 +227,7 @@ func (msg *L1IncomingMessage) FillInBatchGasFieldsWithParentBlock(batchFetcher F
 			// missing BatchDataStats and fail there, since it does know the arbos
 			// version. In practice, any node that supports arbos50 populates both
 			// fields together, so this fallback path should not be reached.
-			log.Warn("Failed reading batch data for filling message - leaving BatchDataStats empty")
+			log.Warn("Failed reading batch data for filling message - leaving BatchDataStats empty", "batchNum", batchNum, "err", err)
 			return nil
 		} else {
 			gotHash := crypto.Keccak256Hash(batchData)