In Wireshark 2.2.0 to 2.2.6 and 2.0.0 to 2.0.12, the DNS dissector could go into an infinite loop. This was addressed in epan/dissectors/packet-dns.c by trying to detect self-referencing pointers.
www.securityfocus.com/bid/98798
www.securitytracker.com/id/1038612
bugs.chromium.org/p/oss-fuzz/issues/detail?id=1206
bugs.wireshark.org/bugzilla/show_bug.cgi?id=13633
code.wireshark.org/review/gitweb?p=wireshark.git%3Ba=commit%3Bh=e280c9b637327a65d132bfe72d917b87e6844eb5
www.wireshark.org/security/wnpa-sec-2017-26.html