From 0002d8322260ad0ae4c7f4266ca7494194f12d45 Mon Sep 17 00:00:00 2001
From: "Mark D. Roth" <roth@google.com>
Date: Thu, 25 Aug 2016 07:57:24 -0700
Subject: [PATCH] Fix crash caused by invoking receive callback with
 recv_message=NULL.

---
 src/core/lib/channel/message_size_filter.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/core/lib/channel/message_size_filter.c b/src/core/lib/channel/message_size_filter.c
index 78aafc7d3d5..10cb1998d13 100644
--- a/src/core/lib/channel/message_size_filter.c
+++ b/src/core/lib/channel/message_size_filter.c
@@ -63,7 +63,8 @@ static void recv_message_ready(grpc_exec_ctx* exec_ctx, void* user_data,
   grpc_call_element* elem = user_data;
   call_data* calld = elem->call_data;
   channel_data* chand = elem->channel_data;
-  if ((*calld->recv_message)->length > chand->max_recv_size) {
+  if (*calld->recv_message != NULL &&
+      (*calld->recv_message)->length > chand->max_recv_size) {
     char* message_string;
     gpr_asprintf(&message_string, "Received message larger than max (%lu)",
                  (unsigned long)chand->max_recv_size);