From: Otto Moerbeek <otto.moerbeek@open-xchange.com>
Date: Wed, 6 Apr 2022 09:17:48 +0000 (+0200)
Subject: Another case of unaligned access of header data found by ubsan on OpenSBD
X-Git-Tag: rec-4.7.0-beta1~11^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=17c011cd73833529e044e88bbddfb912a60cab6e;p=thirdparty%2Fpdns.git

Another case of unaligned access of header data found by ubsan on OpenSBD
---

diff --git a/pdns/packetcache.hh b/pdns/packetcache.hh
index 82f22ffcf1..eba68221f6 100644
--- a/pdns/packetcache.hh
+++ b/pdns/packetcache.hh
@@ -174,7 +174,8 @@ public:
        + the OPT RR rdlen (2)
        = 15
     */
-    const struct dnsheader* dh = reinterpret_cast<const struct dnsheader*>(query.data());
+    const dnsheader_aligned dnsheaderdata(query.data());
+    const struct dnsheader* dh = dnsheaderdata.get();    
     if (ntohs(dh->qdcount) != 1 || ntohs(dh->ancount) != 0 || ntohs(dh->nscount) != 0 || ntohs(dh->arcount) != 1 || (pos + 15) >= querySize || optionsToIgnore.empty()) {
       return cachedQuery.compare(pos, cachedQuerySize - pos, query, pos, querySize - pos) == 0;
     }