We consider the stability of the discrete-time networked control systems (NCSs) with polytopic uncertainty, where a smart controller is updated with the buffered sensor information at stochastic intervals and the amount of the buffered data received by the controller under the buffer capacity constraint is also random. We establish sufficient conditions for guaranteeing the exponential stability of generic switched NCSs and the exponential mean square stability of Markov-chain driven NCSs, respectively. An illustrative example is given to demonstrate the effectiveness of our results.