Re: [HEADS UP] Default value of SELinux boolean httpd_graceful_shutdown will changed.

[Lukas Vrabec]

On 09/29/2017 03:57 PM, Alexander Bokovoy wrote:
>  On pe, 29 syys 2017, Lukas Vrabec wrote:
> > I'm planning change the default value of httpd_graceful_shutdown 
> > boolean in Fedora Rawhide because of improving SELinux configuration. 
> > Rawhide builds with this change will be available in ~5 days.
> >
> > Together with Dan Walsh, we agreed on that httpd_graceful_shutdown 
> > boolean should be by default turned off. This boolean allows HTTPD to 
> > connect to port 80 for graceful shutdown, but it's breaking the 
> > functionality of another boolean called: httpd_can_network_connect. 
> > This boolean allows HTTPD scripts and modules to connect to the 
> > network using TCP and it's turned off by default.
> >
> > Turning this boolean off can cause some troubles, on web-servers where 
> > processes with httpd_t SELinux domain connecting to tcp ports: 80, 81, 
> > 443, 488, 8008, 8009, 8443, 9000
> >
> > If you would like to turn in on again, use semanage command:
> > # semanage boolean -m --on httpd_graceful_shutdown
>  In FreeIPA we have httpd_can_network_connect enabled. I just checked a F26
>  system and I have both booleans enabled.
>  
>  # getsebool -a|egrep 'httpd_graceful_shutdown|httpd_can_network_connect '
>  httpd_can_network_connect --> on
>  httpd_graceful_shutdown --> on
>  
>  So I'm a bit confused: disabling httpd_graceful_shutdown will have or
>  wouldn't have an effect on httpd_can_network_connect being enabled?
>   
httpd_graceful_shutdown is subset of httpd_can_network_connect.

Turning on httpd_graceful_shutdown you allow httpd_t domain connecting 
just to ports labeled as httpd_port_t.
Turning on httpd_can_network_connect you allow httpd_t domain connecting 
to all ports from SELinux POV.

Right now, we ship selinux-policy with httpd_graceful_shutdown turned on 
and httpd_can_network_connect turned off. But it's confusing for users 
because they have httpd_can_connect turned off but httpd_t domain can 
still connect co http_port_t ports becuase of httpd_gracefull_shudown.

I hope it's more clear now.


>  Do I need to do anything in FreeIPA setup?
>   
No if httpd_can_network_connect is enabled during FreeIPA setup, you 
don't need to change anything.

Lukas.



-- 
Lukas Vrabec
Software Engineer, Security Technologies
Red Hat, Inc.