output: #fixed code
                                  private Response singleDeviceOTA(ChannelHandlerContext ctx, String token, String path) {
          TokenValue tokenValue = tokenManager.getTokenValueByToken(token);
  
          if (tokenValue == null) {
              log.debug("Requested token {} not found.", token);
              return badRequest("Invalid token.");
          }
  
          User user = tokenValue.user;
          int dashId = tokenValue.dash.id;
          int deviceId = tokenValue.deviceId;
  
          Session session = sessionDao.userSession.get(new UserKey(user));
          if (session == null) {
              log.debug("No session for user {}.", user.email);
              return badRequest("Device wasn't connected yet.");
          }
  
          String body = otaManager.buildOTAInitCommandBody(path);
          if (session.sendMessageToHardware(dashId, BLYNK_INTERNAL, 7777, body, deviceId)) {
              log.debug("No device in session.");
              return badRequest("No device in session.");
          }
  
          Device device = tokenValue.dash.getDeviceById(deviceId);
  
          User initiator = ctx.channel().attr(AuthHeadersBaseHttpHandler.USER).get();
          if (initiator != null) {
              device.updateOTAInfo(initiator.email);
          }
  
          return ok(path);
      }
input: #vulnerable code 
                                  private Response singleDeviceOTA(ChannelHandlerContext ctx, String token, String path) {
          TokenValue tokenValue = tokenManager.getTokenValueByToken(token);
  
          if (tokenValue == null) {
              log.debug("Requested token {} not found.", token);
              return badRequest("Invalid token.");
          }
  
          User user = tokenValue.user;
          int dashId = tokenValue.dashId;
          int deviceId = tokenValue.deviceId;
  
          Session session = sessionDao.userSession.get(new UserKey(user));
          if (session == null) {
              log.debug("No session for user {}.", user.email);
              return badRequest("Device wasn't connected yet.");
          }
  
          String body = otaManager.buildOTAInitCommandBody(path);
          if (session.sendMessageToHardware(dashId, BLYNK_INTERNAL, 7777, body, deviceId)) {
              log.debug("No device in session.");
              return badRequest("No device in session.");
          }
  
          DashBoard dash = user.profile.getDashById(dashId);
          Device device = dash.getDeviceById(deviceId);
  
          User initiator = ctx.channel().attr(AuthHeadersBaseHttpHandler.USER).get();
          if (initiator != null) {
              device.updateOTAInfo(initiator.email);
          }
  
          return ok(path);
      } 
                              #location 26 
                              #vulnerability type NULL_DEREFERENCE