[mojo-edk] Sanity checks on ports message parsing

mojo/edk/system/node_controller.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/edk/system/node_controller.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/bind.h"
@@ skipping 768 matching lines @@
     while (!message_queue.empty()) {
       broker->RelayPortsMessage(destination, std::move(message_queue.front()));
       message_queue.pop();
     }
   }
 #endif
 
   DVLOG(1) << "Child " << name_ << " accepted by broker " << broker_name;
 }
 
-void NodeController::OnPortsMessage(Channel::MessagePtr channel_message) {
+void NodeController::OnPortsMessage(const ports::NodeName& from_node,
+                                    Channel::MessagePtr channel_message) {
   DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
 
   void* data;
   size_t num_data_bytes;
   NodeChannel::GetPortsMessageData(
       channel_message.get(), &data, &num_data_bytes);
+  if (!num_data_bytes) {
+    DropPeer(from_node);
+    return;
+  }
 
   size_t num_header_bytes, num_payload_bytes, num_ports_bytes;
-  ports::Message::Parse(data,
-                        num_data_bytes,
-                        &num_header_bytes,
-                        &num_payload_bytes,
-                        &num_ports_bytes);
+  if (!ports::Message::Parse(data,
+                             num_data_bytes,
+                             &num_header_bytes,
+                             &num_payload_bytes,
+                             &num_ports_bytes)) {
+    DropPeer(from_node);
+    return;
+  }
 
   CHECK(channel_message);
   ports::ScopedMessage message(
       new PortsMessage(num_header_bytes,
                        num_payload_bytes,
                        num_ports_bytes,
                        std::move(channel_message)));
 
   node_->AcceptMessage(std::move(message));
   AcceptIncomingMessages();
@@ skipping 108 matching lines @@
     // process. At this point, if the port extraction failed, either something
     // went wrong in the mach stuff, or the remote process died.
     LOG(ERROR) << "Error on receiving Mach ports " << from_node
                << ". Dropping message.";
     return;
   }
 #endif  // defined(OS_WIN)
 
   if (destination == name_) {
     // Great, we can deliver this message locally.
-    OnPortsMessage(std::move(message));
+    OnPortsMessage(from_node, std::move(message));
     return;
   }
 
   scoped_refptr<NodeChannel> peer = GetPeerChannel(destination);
   if (peer)
     peer->PortsMessage(std::move(message));
   else
     DLOG(ERROR) << "Dropping relay message for unknown node " << destination;
 }
 #endif
@@ skipping 41 matching lines @@
     shutdown_callback_.Reset();
   }
 
   DCHECK(!callback.is_null());
 
   callback.Run();
 }
 
 }  // namespace edk
 }  // namespace mojo