| Subject: | Fatal error upon invalid SPF record |
| Date: | Wed, 10 Apr 2013 17:16:44 +0200 |
| To: | bug-net-dns [...] rt.cpan.org |
| From: | Thomas Sturm <thomas.sturm [...] yahoo.de> |
There is a domain with a SPF record like
mydomain.com. 3600 IN TXT "v=spf1 include:.anotherdomain.com ~all"
This is obviously invalid, but things like that happen out there.
Now there is a mailserver, which is checking SPF records using some
perl daemon, which is using Mail::SPF. For this, Mail::SPF then performs
DNS lookups using Net::DNS. This fails with a record like above, and,
end of the story, the perl daemon crashes.
I tried to find out where exactly the fatal operation is performed, and
by sniffing the TCP traffic between postfix and the perl daemon, it
turned out this happens in Net::DNS::Packet. Please see the full trace
below:
*** FATAL PROGRAM ERROR!!\x09Unknown method 'default'\x0a*** which
the program has attempted to call for the object:\x0a***\x0a*** ; EDNS
Version \x09 UDP Packetsize: IN\x0a; EDNS-RCODE:\x09 ()\x0a;
EDNS-FLAGS:\x090x0000\x0a\x0a***\x0a*** This object does not have a
method 'default'. THIS IS A BUG\x0a*** IN THE CALLING SOFTWARE, which
incorrectly assumes that the\x0a*** object would be of a particular
type. The type of an object\x0a*** should be checked before calling
any of its methods.\x0a at
/usr/lib/i686-linux-thread-multi/Net/DNS/Packet.pm line
183\x0a\x09Net::DNS::Packet::data('Net::DNS::Packet=HASH(0x86dadc8)')
called at /usr/lib/i686-linux-thread-multi/Net/DNS/Resolver/Base.pm line
500\x0a\x09Net::DNS::Resolver::Base::send('Net::DNS::Resolver=HASH(0x86d3db0)',
'mta.mydomain.com', 'TXT') called at
/usr/lib/i686-linux-thread-multi/Mail/SPF/Server.pm line
564\x0a\x09Mail::SPF::Server::dns_lookup('Mail::SPF::Server=HASH(0x83d3ee0)',
'mta.mydomain.com', 'TXT') called at
/usr/lib/i686-linux-thread-multi/Mail/SPF/Server.pm line
461\x0a\x09Mail::SPF::Server::__ANON__() called at
/usr/lib/i686-linux-thread-multi/Error.pm line 419\x0a\x09eval {...}
called at /usr/lib/i686-linux-thread-multi/Error.pm line
411\x0a\x09Error::subs::try('CODE(0x86da9b8)', 'HASH(0x86daae8)') called
at /usr/lib/i686-linux-thread-multi/Mail/SPF/Server.pm line
470\x0a\x09Mail::SPF::Server::select_record('Mail::SPF::Server=HASH(0x83d3ee0)',
'Mail::SPF::Request=HASH(0x86d4110)') called at
/usr/lib/i686-linux-thread-multi/Mail/SPF/Server.pm line
323\x0a\x09Mail::SPF::Server::__ANON__() called at
/usr/lib/i686-linux-thread-multi/Error.pm line 419\x0a\x09eval {...}
called at /usr/lib/i686-linux-thread-multi/Error.pm line
411\x0a\x09Error::subs::try('CODE(0x86da1d8)', 'HASH(0x86da668)') called
at /usr/lib/i686-linux-thread-multi/Mail/SPF/Server.pm line
344\x0a\x09Mail::SPF::Server::process('Mail::SPF::Server=HASH(0x83d3ee0)',
'Mail::SPF::Request=HASH(0x86d4110)') called at /usr/bin/policy-spf.pl
line 263\x0a\x09main::sender_policy_framework('attr', 'HASH(0x8305940)',
'cache', 'HASH(0x86d42e0)') called at /usr/bin/policy-spf.pl line
168.\x0a