From c898417302f4f28013e7cc21bb4476d150c962cf Mon Sep 17 00:00:00 2001
From: "Mark D. Roth" <roth@google.com>
Date: Thu, 8 Dec 2016 09:40:33 -0800
Subject: [PATCH] Fix race condition on shutdown.

---
 src/core/lib/security/transport/security_handshaker.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/core/lib/security/transport/security_handshaker.c b/src/core/lib/security/transport/security_handshaker.c
index 628c747bf6e..41a775db855 100644
--- a/src/core/lib/security/transport/security_handshaker.c
+++ b/src/core/lib/security/transport/security_handshaker.c
@@ -131,6 +131,9 @@ static void security_handshake_failed_locked(grpc_exec_ctx *exec_ctx,
     // Not shutting down, so the write failed.  Clean up before
     // invoking the callback.
     cleanup_args_for_failure_locked(h);
+    // Set shutdown to true so that subsequent calls to
+    // security_handshaker_shutdown() do nothing.
+    h->shutdown = true;
   }
   // Invoke callback.
   grpc_exec_ctx_sched(exec_ctx, h->on_handshake_done, error, NULL);