[mpm-itk] Ubuntu 14.04 mpm-itk binary missing

Henk Kraal h.kraal at tiw.nl
Wed May 14 13:33:38 CEST 2014

On 05/14/2014 12:00 PM, mpm-itk-request at err.no wrote:
> Your conclusion is pretty far off.:-)  In newer Apache (such as the one
> in 14.04), MPMs are no longer supposed to be built into the Apache binaries,
> but are separate modules. Furthermore, in newer mpm-itk (such as the one
> presumably in 14.04), mpm-itk isn't actually a true MPM anymore, just a
> module that hooks into mpm-prefork at appropriate places.
> So you'll need the apache2 binary, the prefork MPM and the ITK MPM (or
> module).
> The fact that ps doesn't show it to run as root anymore is unrelated to this,
> and largely a result of improved capability support in newer mpm-itk. It can
> still setuid, so in many ways, it's still pretty much equivalent to root.
> As for your internal errors, you should probably look into the Apache error
> logs and see what they say.
> /* Steinar */
> -- Homepage: http://www.sesse.net/

Sorry if this reply doesn't end up on the correct thread, I had digests 
enabled and I'm finding myself being unsure how to reply in the correct way.

You're very kind, "Pretty far off" is putting it mildly, it's more that 
I've totally missed it. This information helped me a great deal towards 
finding a solution without getting send in the wrong way. I assumed that 
mpm-itk wasn't working correctly due the internal error but it was 
something else.

I think I found a problem with the integer containing the uid/gid of the 
user in question. This seems to be limited to 65535 causing my internal 

~# grep AssignUserId /etc/apache2/sites-enabled/url.to.vhost.conf
     AssignUserId test test

~# grep test /etc/passwd

The test:
~# usermod -u 65535 test && /etc/init.d/apache2 reload && wget -nv -O 
/dev/null "http://url.to.vhost/phpinfo.php"
  * Reloading web server apache2
2014-05-14 13:23:07 URL:http://url.to.vhost/phpinfo.php [84984] -> 
"/dev/null" [1]

~# usermod -u 65536 test && /etc/init.d/apache2 reload && wget -nv -O 
/dev/null "http://url.to.vhost/phpinfo.php"
  * Reloading web server apache2
2014-05-14 13:24:02 ERROR 500: Internal Server Error.

~# tail /var/log/apache/error.log
[Wed May 14 13:25:48.294129 2014] [mpm_itk:warn] [pid 11206] (itkmpm: 
pid=11206 uid=33, gid=1004) itk_post_perdir_config(): setuid(65536): 
Operation not permitted

 From the source it seems that mpm-itk should work up to UINT_MAX which 
is 4294967295 as I gather from my limits.h.

With kind regards,

Henk Kraal

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