From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Tue, 5 Dec 2017 16:07:19 +0000 (+0100)
Subject: dnsreplay: Bail out on a too small outgoing buffer
X-Git-Tag: dnsdist-1.3.1~113^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F6580%2Fhead;p=thirdparty%2Fpdns.git

dnsreplay: Bail out on a too small outgoing buffer
---

diff --git a/pdns/dnsreplay.cc b/pdns/dnsreplay.cc
index a95a233f34..99ddaffad4 100644
--- a/pdns/dnsreplay.cc
+++ b/pdns/dnsreplay.cc
@@ -590,7 +590,7 @@ static void addECSOption(char* packet, const size_t& packetSize, uint16_t* len,
 
   uint16_t arcount = ntohs(dh->arcount);
   /* does it fit in the existing buffer? */
-  if (packetSize - *len > EDNSRR.size()) {
+  if (packetSize > *len && packetSize - *len > EDNSRR.size()) {
     arcount++;
     dh->arcount = htons(arcount);
     memcpy(packet + *len, EDNSRR.c_str(), EDNSRR.size());