From 9cf08b6bea66a801506f66193389822d3049c112 Mon Sep 17 00:00:00 2001
From: Robbie Shade <rjshade@google.com>
Date: Tue, 7 Mar 2017 10:34:17 -0500
Subject: [PATCH] Fix flaky use-after-free in udp_server

---
 src/core/lib/iomgr/udp_server.c | 6 +++++-
 third_party/gflags              | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/core/lib/iomgr/udp_server.c b/src/core/lib/iomgr/udp_server.c
index 2a1c8d39fae..d1bcd89af1f 100644
--- a/src/core/lib/iomgr/udp_server.c
+++ b/src/core/lib/iomgr/udp_server.c
@@ -485,7 +485,11 @@ void grpc_udp_server_start(grpc_exec_ctx *exec_ctx, grpc_udp_server *s,
                       grpc_schedule_on_exec_ctx);
     grpc_fd_notify_on_write(exec_ctx, sp->emfd, &sp->write_closure);
 
-    s->active_ports++;
+    /* Registered for both read and write callbacks: increment active_ports
+     * twice to account for this, and delay free-ing of memory until both
+     * on_read and on_write have fired. */
+    s->active_ports += 2;
+
     sp = sp->next;
   }
 
diff --git a/third_party/gflags b/third_party/gflags
index 30dbc81fb5f..f8a0efe03aa 160000
--- a/third_party/gflags
+++ b/third_party/gflags
@@ -1 +1 @@
-Subproject commit 30dbc81fb5ffdc98ea9b14b1918bfe4e8779b26e
+Subproject commit f8a0efe03aa69b3336d8e228b37d4ccb17324b88