[mojo-edk] Add some buffer checks and fix UAF on NodeChannel

mojo/edk/system/data_pipe_consumer_dispatcher.cc

Index: mojo/edk/system/data_pipe_consumer_dispatcher.cc
diff --git a/mojo/edk/system/data_pipe_consumer_dispatcher.cc b/mojo/edk/system/data_pipe_consumer_dispatcher.cc
index 6d1b618fd7fc2595b4f3076007021f4a4042f6b6..23cb2e0368df750d86ee6d4f0f094373e6ccb9b5 100644
--- a/mojo/edk/system/data_pipe_consumer_dispatcher.cc
+++ b/mojo/edk/system/data_pipe_consumer_dispatcher.cc
@@ -531,6 +531,11 @@ void DataPipeConsumerDispatcher::UpdateSignalsStateNoLock() {
       if (rv != ports::OK)
         peer_closed_ = true;
       if (message) {
+        if (message->num_payload_bytes() < sizeof(DataPipeControlMessage)) {
+          peer_closed_ = true;
+          break;
+        }
+
         const DataPipeControlMessage* m =
             static_cast<const DataPipeControlMessage*>(
                 message->payload_bytes());