output: #fixed code
                                  public void requestTxGroup(NulsDigestData blockHash, String nodeId) {
          GetTxGroupRequest request = new GetTxGroupRequest();
          GetTxGroupParam data = new GetTxGroupParam();
          data.setBlockHash(blockHash);
          List<NulsDigestData> txHashList = new ArrayList<>();
  
          SmallBlock smb = temporaryCacheManager.getSmallBlock(blockHash.getDigestHex());
          for (NulsDigestData txHash : smb.getTxHashList()) {
              boolean exist = txCacheManager.txExist(txHash);
              if (!exist) {
                  txHashList.add(txHash);
              }
          }
          if (txHashList.isEmpty()) {
              BlockHeader header = temporaryCacheManager.getBlockHeader(smb.getBlockHash().getDigestHex());
              if (null == header) {
                  return;
              }
              Block block = new Block();
              block.setHeader(header);
              List<Transaction> txs = new ArrayList<>();
              for (NulsDigestData txHash : smb.getTxHashList()) {
                  Transaction tx = txCacheManager.getTx(txHash);
                  if (null == tx) {
                      throw new NulsRuntimeException(ErrorCode.DATA_ERROR);
                  }
                  txs.add(tx);
              }
              block.setTxs(txs);
              ValidateResult vResult = block.verify();
              if (vResult.isFailed()&&vResult.getErrorCode()!=ErrorCode.ORPHAN_BLOCK&&vResult.getErrorCode()!=ErrorCode.ORPHAN_TX) {
                  return;
              }
              blockManager.addBlock(block, false,nodeId);
              AssembledBlockNotice notice = new AssembledBlockNotice();
              notice.setEventBody(header);
              eventBroadcaster.publishToLocal(notice);
              return;
          }
          data.setTxHashList(txHashList);
          request.setEventBody(data);
          tgRequest.put(blockHash.getDigestHex(), System.currentTimeMillis());
          Integer value = tgRequestCount.get(blockHash.getDigestHex());
          if (null == value) {
              value = 0;
          }
          tgRequestCount.put(blockHash.getDigestHex(), 1 + value);
          if (StringUtils.isBlank(nodeId)) {
              eventBroadcaster.broadcastAndCache(request, false);
          } else {
              eventBroadcaster.sendToNode(request, nodeId);
          }
      }
input: #vulnerable code 
                                  public void requestTxGroup(NulsDigestData blockHash, String nodeId) {
          GetTxGroupRequest request = new GetTxGroupRequest();
          GetTxGroupParam data = new GetTxGroupParam();
          data.setBlockHash(blockHash);
          List<NulsDigestData> txHashList = new ArrayList<>();
  
          SmallBlock smb = temporaryCacheManager.getSmallBlock(blockHash.getDigestHex());
          for (NulsDigestData txHash : smb.getTxHashList()) {
              boolean exist = txCacheManager.txExist(txHash);
              if (!exist) {
                  txHashList.add(txHash);
              }
          }
          if (txHashList.isEmpty()) {
              BlockHeader header = temporaryCacheManager.getBlockHeader(smb.getBlockHash().getDigestHex());
              if (null == header) {
                  return;
              }
              Block block = new Block();
              block.setHeader(header);
              List<Transaction> txs = new ArrayList<>();
              for (NulsDigestData txHash : smb.getTxHashList()) {
                  Transaction tx = txCacheManager.getTx(txHash);
                  if (null == tx) {
                      throw new NulsRuntimeException(ErrorCode.DATA_ERROR);
                  }
                  txs.add(tx);
              }
              block.setTxs(txs);
              ValidateResult<RedPunishData> vResult = block.verify();
              if (null == vResult || vResult.isFailed()) {
                  if (vResult.getLevel() == SeverityLevelEnum.FLAGRANT_FOUL) {
                      RedPunishData redPunishData = vResult.getObject();
                      ConsensusMeetingRunner.putPunishData(redPunishData);
                  }
                  return;
              }
              blockManager.addBlock(block, false,nodeId);
              AssembledBlockNotice notice = new AssembledBlockNotice();
              notice.setEventBody(header);
              eventBroadcaster.publishToLocal(notice);
              return;
          }
          data.setTxHashList(txHashList);
          request.setEventBody(data);
          tgRequest.put(blockHash.getDigestHex(), System.currentTimeMillis());
          Integer value = tgRequestCount.get(blockHash.getDigestHex());
          if (null == value) {
              value = 0;
          }
          tgRequestCount.put(blockHash.getDigestHex(), 1 + value);
          if (StringUtils.isBlank(nodeId)) {
              eventBroadcaster.broadcastAndCache(request, false);
          } else {
              eventBroadcaster.sendToNode(request, nodeId);
          }
      } 
                              #location 32 
                              #vulnerability type NULL_DEREFERENCE