[CentOS-docs] SELinux

Tue Aug 12 14:18:29 UTC 2008
Ned Slider <ned at unixmail.co.uk>

Manuel Wolfshant wrote:
> Ned Slider wrote:
>> Hi list,
>> I've knocked up a contribution on SELinux here:
>> http://wiki.centos.org/HowTos/SELinux
>> I've tried to pitch it as an introduction for those not already 
>> familiar with SELinux but also hopefully a useful reference.
>> I'm relatively new to SELinux and have covered pretty much everything 
>> I know to the limits of my limited knowledge. If folks think other 
>> material needs to be covered then it may be more appropriate for them 
>> to make the additions rather than me. Consider it a "get the ball 
>> rolling" contribution that the community can add to as necessary :)
>> Comments welcomed,
> I would add the following just before "Sumamry" (in case one wants to 
> edit the rules suggested by audit2allow):
>    Building module policy manually
> - grep sendmail /var/log/audit/audit.log | audit2allow -M postfix
> - while reviewing the generated postfix.te
>    module local 1.0;
>    require {
>            type httpd_log_t;
>            type postfix_postdrop_t;
>            class dir getattr;
>            class file { read getattr };
>    }
>    #============= postfix_postdrop_t ==============
>    allow postfix_postdrop_t httpd_log_t:file getattr;
> we decide that we do not want either to *relabel* the files or to 
> *allow* the action, but it is safe to *ignore* the warnings. Therefore 
> we edit the action rule, like below:
>    dontaudit postfix_postdrop_t httpd_log_t:file getattr;
> We now need to compile and load the policy:
>    $ checkmodule -M -m -o postfix.mod postfix.te
>    $ semodule_package -o local.pp -m postfix.mod
>    $ semodule -i postfix.pp

Thanks Wolfy :)

I think I need to read up some more and expand section(s) at the end of 
the document on policy modules. I'll incorporate the above into that 

Also, does anyone know if there are any guidelines/best practice on the 
naming of custom policy modules? I'm wondering if it's wise to create 
local policy modules with names like postfix or postgrey etc, as 
conceivably these may later get overwritten by policy modules supplied 
from elsewhere? Maybe something like postfix.local.pp might be more