From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Fri, 10 Oct 2025 14:39:56 +0000 (+0200)
Subject: dnsdist: Properly zero-initialize the "fake" DNS header
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7e4a01d6cfc437e39b445ca1ef494b4162f40d7a;p=thirdparty%2Fpdns.git

dnsdist: Properly zero-initialize the "fake" DNS header

Signed-off-by: Remi Gacogne <remi.gacogne@powerdns.com>
(cherry picked from commit 153a1bf296f58c38cfd4fb96de29e2677ac42e04)
---

diff --git a/pdns/dnsdistdist/dnsdist.cc b/pdns/dnsdistdist/dnsdist.cc
index e595d4ee38..40506e4a14 100644
--- a/pdns/dnsdistdist/dnsdist.cc
+++ b/pdns/dnsdistdist/dnsdist.cc
@@ -1593,9 +1593,11 @@ bool handleTimeoutResponseRules(const std::vector<dnsdist::rules::ResponseRuleAc
   /* let's be nice and restore the original DNS header as well as we can with what we have */
   PacketBuffer payload(sizeof(dnsheader));
   dnsdist::PacketMangling::editDNSHeaderFromPacket(payload, [&ids](dnsheader& header) {
+    memset(&header, 0, sizeof(header));
     header.id = ids.origID;
-    header.qdcount = htons(1);
     restoreFlags(&header, ids.origFlags);
+    // do not set the qdcount, otherwise the protobuf code will choke on it
+    // while trying to parse the response RRs
     return true;
   });
   DNSResponse dnsResponse(ids, payload, d_ds);