resolv: Fix memory leak with OOM during resolv.conf parsing [BZ #22095]

ChangeLog

@@ -1,3 +1,9 @@
+2017-09-06  Florian Weimer  <fweimer@redhat.com>
+
+	[BZ #22095]
+	* resolv/res_init.c (res_vinit_1): Avoid memory leak in case of
+	dynarray allocation failure.
+
 2017-09-06  Florian Weimer  <fweimer@redhat.com>
 
 	Remove dead PTR IPv4-to-IPv6 mapping code from nss_dns.

resolv/res_init.c

@@ -446,6 +446,11 @@ res_vinit_1 (FILE *fp, struct resolv_conf_parser *parser)
                     (&parser->nameserver_list);
                   if (p != NULL)
                     *p = sa;
+                  else
+                    {
+                      free (sa);
+                      return false;
+                    }
                 }
               continue;
             }