From: Christopher Faulet <cfaulet@haproxy.com>
Date: Thu, 22 Jul 2021 12:29:26 +0000 (+0200)
Subject: BUG/MINOR: resolvers: Use a null-terminated string to lookup in servers tree
X-Git-Tag: v2.5-dev3~35
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1f923391d1841435de7891682f585c040faef2bc;p=thirdparty%2Fhaproxy.git

BUG/MINOR: resolvers: Use a null-terminated string to lookup in servers tree

When we evaluate a DNS response item, it may be necessary to look for a
server with a hostname matching the item target into the named servers
tree. To do so, the item target is transformed to a lowercase string. It
must be a null-terminated string. Thus we must explicitly set the trailing
'\0' character.

For a specific resolution, the named servers tree contains all servers using
this resolution with a hostname loaded from a state file. Because of this
bug, same entry may be duplicated because we are unable to find the right
server, assigning this way the item to a free server slot.

This patch should fix the issue #1333. It must be backported as far as 2.2.
---

diff --git a/src/resolvers.c b/src/resolvers.c
index 0a4ea3528b..1704d7227a 100644
--- a/src/resolvers.c
+++ b/src/resolvers.c
@@ -694,6 +694,7 @@ static void resolv_check_response(struct resolv_resolution *res)
 				/* convert the key to lookup in lower case */
 				for (i = 0 ; item->target[i] ; i++)
 					target[i] = tolower(item->target[i]);
+				target[i] = 0;
 
 				node = ebis_lookup(&srvrq->named_servers, target);
 				if (node) {