From 3a8532219a0531d5fbb33e7f4c2f9531c4c924b9 Mon Sep 17 00:00:00 2001
From: Ruslan Ermilov <ru@nginx.com>
Date: Fri, 16 Dec 2016 14:53:28 +0300
Subject: [PATCH] Resolver: fixed possible use-after-free in worker on fast
 shutdown.

The fix in a3dc657f4e95 was incomplete.
---
 src/core/ngx_resolver.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index 834196a0a..fc25c6633 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -351,6 +351,10 @@ ngx_resolver_cleanup_tree(ngx_resolver_t *r, ngx_rbtree_t *tree)
             next = ctx->next;
 
             if (ctx->event) {
+                if (ctx->event->timer_set) {
+                    ngx_del_timer(ctx->event);
+                }
+
                 ngx_resolver_free(r, ctx->event);
             }