How To Block Spammers/Hackers With mod_defensible On Apache2 - php problem

[le_avion]

My server is running Ubuntu 7.10 and I ran into a problem after installing and configuring mod_defensible. The problem that I ran into is that my php pages are no longer handled by the server and instead my browser offers to download the page php source.

In Apache's error.log I see the following which is probably related:

apache2: udns_resolver.c:477: dns_free: Assertion `ctx != ((void *)0) && ctx != &dns_defctx' failed.
[Sun Jul 13 12:06:00 2008] [notice] child pid 7803 exit signal Aborted (6)

I wonder what is the reason for this problem.

Avi

[falko]

And when you comment out the three mod_defensible directives and restart Apache, PHP works again?

[le_avion]

This is correct. When I comment the lines out PHP starts working again.

Avi

[falko]

Hm... What's in /etc/resolv.conf?

[le_avion]

search cfftechnologies.com
nameserver 192.168.129.1
nameserver 68.87.72.130
nameserver 68.87.77.130


The first name server is my own caching name server.

Avi

[falko]

Can you try this in the first place in /etc/resolv.conf?

nameserver 145.253.2.75

[le_avion]

First I would like to thank you for trying to get my issue resolved.

This did not help but I did get it working properly now. Seems that the version of mod_defensible in Ubuntu 7.10 has a bug. I found a reference to the same problem I am having in a Debian bug report. I ended up installing the newer libudns0 and mod_defensible from Hardy (Ubuntu 8.04) and that fixed the problem. I will file a bug report with Ubuntu and ask them to back port it to 7.10 since it is still a supported version. From the Debian bug report:

libapache2-mod-defenisble has a serious issue involving dns resolution in
the testing tree. Anytime you activate and use the module the following
critical error is thrown by Apache:

[Mon Sep 17 10:48:25 2007] [notice] child pid 30877 exit signal Aborted (6)

apache2: udns_resolver.c:477: dns_free: Assertion `ctx != ((void *)0) && ctx
!= &dns_defctx' failed.

This is a blocker issue that prevents Apache from serving any requests while
the module is activated.