Use of uninitialized value $this_domain
orlitzky opened this issue · 2 comments
When receiving an email from a malformed address, the following can be logged:
Jul 7 01:22:58 mx1 amavis[2269]: (02269-07) _WARN: Use of uninitialized value $this_domain in concatenation (.) or string at /usr/lib64/perl5/vendor_perl/5.28.2/Mail/SpamAssassin/Plugin/SH.pm line 172.
Jul 7 01:22:58 mx1 amavis[2269]: (02269-07) _WARN: Use of uninitialized value $this_domain in hash element at /usr/lib64/perl5/vendor_perl/5.28.2/Mail/SpamAssassin/Plugin/SH.pm line 173.
Jul 7 01:22:58 mx1 amavis[2269]: (02269-07) _WARN: Use of uninitialized value $this_domain in hash element at /usr/lib64/perl5/vendor_perl/5.28.2/Mail/SpamAssassin/Plugin/SH.pm line 174.
Jul 7 01:22:58 mx1 amavis[2269]: (02269-07) _WARN: Use of uninitialized value $this_domain in hash element at /usr/lib64/perl5/vendor_perl/5.28.2/Mail/SpamAssassin/Plugin/SH.pm line 196.
Jul 7 01:22:58 mx1 amavis[2269]: (02269-07) _WARN: Use of uninitialized value $this_domain in concatenation (.) or string at /usr/lib64/perl5/vendor_perl/5.28.2/Mail/SpamAssassin/Plugin/SH.pm line 197.
These lead to,
Jul 7 01:22:58 mx1 amavis[2269]: (02269-07) _WARN: dns: new_dns_packet (domain=.<my_DQS_key>.zrd.dq.spamhaus.net. type=A class=IN) failed: a domain name contains a null label
Now, this was a message we probably shouldn't have accepted in the first place: the sender's address was a bare hostname (e.g. foo.bar.invalid). However, it was to our postmaster address, and we're pretty lenient with what we'll accept to postmaster, so that people can effectively complain if I screw things up.
From looking at the code, most other places where $this_domain is set first check that the string is an email address (using a regex) before splitting on the @ character to obtain the domain. The sub _get_headers_domains, on the other hand... does some other stuff that I don't understand. I have a copy of the email that triggered the warnings, though, and the "From:" header contains the bare hostname, e.g.
From: foo.bar.invalid
Since that subroutine looks at the "From:" header, he's my primary suspect.
I pushed a fix for checking empty variables, please pull the new SH.pm and let me know
Looks good, thank you!