Re: Re: mod_suexec with mod_userdir and fcgid (webapps in subdirs with separated user context)

[Luca Toscano <toscano.luca@xxxxxxxxx>]

Hi Jonas,

2018-04-23 15:40 GMT+02:00 Jonas Meurer <jonas@xxxxxxxxxxxxxxx>:

Hello again,

maybe my previous mail was to verbose, or maybe simply nobody has an
idea. Still I'd like to give it a second try:

Do you have a good idea why php-cgi7.0 throws the following error when
used with mod_fcgid, mod_usermod and mod_suexec?

uid: (1002/webapp1) gid: (1002/webapp1) cmd: php-fcgi-starter cannot get
docroot information (/var/www/webapp1)

$ ls -al /var/www/webapp1
drwxr-xr-x 9 root root 4096 Jun 29  2014 .
drwxr-x---  2 webapp1 webapp1  4096 Nov  7 15:14 php-fcgi
drwxr-x---  2 webapp1 webapp1  4096 Apr 11  2015 www
[...]

The same setup works perfectly fine without mod_usermod (i.e. when the
whole VHost has a dedicated suexec user). Only with mod_usermod, we get
this strange error.

Premise: I am super ignorant about suexec & C, but this snippet of code in suexec.c seems to be the one returning the error:

    if (getcwd(cwd, AP_MAXPATH) == NULL) {

        log_err("cannot get current working directory\n");

        exit(111);

    }

    if (userdir) {

        if (((chdir(target_homedir)) != 0) ||

            ((chdir(AP_USERDIR_SUFFIX)) != 0) ||

            ((getcwd(dwd, AP_MAXPATH)) == NULL) ||

            ((chdir(cwd)) != 0)) {

            log_err("cannot get docroot information (%s)\n", target_homedir);

            exit(112);

        }

    } 

As far as I can see, this is what it tries to do:

- save the current working dir to 'cwd'

- change dir to "target_homedir", that should be in this case /var/www/webapp1

- change dir to AP_USERDIR_SUFFIX, that if not re-defined should be "public_html" (#define AP_USERDIR_SUFFIX "public_html" in suexec.h)

- set the variable 'dwd' (docroot working directory) to the above

- change dir back to cwd (current working directory) 

So I'd try to add a public_html directory and see how it goes.

Hope that helps!

Luca