From: Emeric Brun <ebrun@haproxy.com>
Date: Mon, 15 Feb 2021 12:58:06 +0000 (+0100)
Subject: BUG/MINOR: dns: add test on result getting value from buffer into ring.
X-Git-Tag: v2.4-dev9~48
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=538bb0441c7a28f27389fce957b3b337e82130d9;p=thirdparty%2Fhaproxy.git

BUG/MINOR: dns: add test on result getting value from buffer into ring.

This patch adds a missing test in dns_session_io_handler, getting
the query id from the buffer of the ring. An error should never
happen since messages are completely added atomically.

This bug should fix github issue #1133
---

diff --git a/src/dns.c b/src/dns.c
index 352e88c9aa..bc40b29e80 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -522,6 +522,13 @@ static void dns_session_io_handler(struct appctx *appctx)
 
 				/* backup original query id */
 				len = b_getblk(buf, (char *)&original_qid, sizeof(original_qid), ofs + cnt);
+				if (!len) {
+					/* should never happen since messages are atomically
+					 * written into ring
+					 */
+					ret = 0;
+					break;
+				}
 
 				/* generates new query id */
 				new_qid = ++ds->query_counter;