From 5ec84574c761c883c0a7d768c417c3278c2c97d9 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Sun, 5 Nov 2017 10:35:57 +0100
Subject: [PATCH] BUG/MAJOR: threads/dns: add missing unlock on allocation
 failure path

An unlock was missing when a memory allocation failure is detected.
---
 src/dns.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/dns.c b/src/dns.c
index c1f3beef5..6b8746090 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -1347,8 +1347,10 @@ int dns_link_resolution(void *requester, int requester_type)
 	if (srv) {
 		SPIN_LOCK(SERVER_LOCK, &srv->lock);
 		if (srv->dns_requester == NULL) {
-			if ((req = calloc(1, sizeof(*req))) == NULL)
+			if ((req = calloc(1, sizeof(*req))) == NULL) {
+				SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
 				goto err;
+			}
 			req->owner         = &srv->obj_type;
 			srv->dns_requester = req;
 		}