Re: [PATCH] serefpolicy: named getattr AVC accessing /dev/random

[Ted Toth]

On Thu, Mar 31, 2011 at 3:19 PM, Dominick Grift <domg472(a)gmail.com&gt; wrote:
>  -----BEGIN PGP SIGNED MESSAGE-----
>  Hash: SHA1
>
>  On 03/31/2011 08:50 PM, Dominick Grift wrote:
> > On 03/31/2011 08:10 PM, Ted Toth wrote:
> >> When I was configuring a local dns server I noticed the following AVC:
> >
> >> type=AVC msg=audit(1301591991.675:24730): avc:  denied  { getattr }
> >> for  pid=23587 comm="named" path="/dev/random" dev=dm-0
> ino=533878
> >> scontext=system_u:system_r:named_t:s0
> >> tcontext=system_u:object_r:named_zone_t:s0 tclass=chr_file
> >
> >> [root@localhost BUILD]# find / -inum 533878
> >> /var/named/chroot/dev/random
> >
> >> I've included a proposed patch below.
> >
> >> Ted
> >
> >> --- serefpolicy-3.9.7/policy/modules/services/bind.fc.orig   2011-03-31
> >> 12:54:32.128829155 -0500
> >> +++ serefpolicy-3.9.7/policy/modules/services/bind.fc        2011-03-31
> >> 12:58:11.849410409 -0500
> >> @@ -60,4 +60,6 @@
> >>  /var/named/chroot/var/named/named\.ca --
> >> gen_context(system_u:object_r:named_conf_t,s0)
> >>  /var/named/chroot/var/log/named.*   --    
>  gen_context(system_u:object_r:named_log_t,s0)
> >>  /var/named/dynamic(/.*)?          
>  gen_context(system_u:object_r:named_cache_t,s0)
> >> +/var/named/chroot/dev/random                --    
>  gen_context(system_u:object_r:random_device_t:s0)
> >> +/var/named/chroot/dev/zero          --    
>  gen_context(system_u:object_r:zero_device_t:s0)
> >
> > Already there in /policy/modules/kernel/devices.fc
> >
> > /var/named/chroot/dev/random -c
> > gen_context(system_u:object_r:random_device_t,s0)
> > /var/named/chroot/dev/zero -c
> > gen_context(system_u:object_r:zero_device_t,s0)
> >
> > Along with:
> >
> > /var/named/chroot/dev -d      gen_context(system_u:object_r:device_t,s0)
> > /var/named/chroot/dev/null -c
> > gen_context(system_u:object_r:null_device_t,s0)
> >
>
>  In theory your patch would not fix it since -- mean single file, and we
>  are we 're dealing with character files here ( -c instead of -- ). 
-c, right that's what I meant to type ;)

>  I guess this may be a good case for "using last path component in type
>  transition rules". 
Yes it seem that this would be a reasonable use of this new type of
transition rule.

>  So that i guess named or initrc can create these nodes with a proper
>  type based on their name, instead of just relying on fc spec and restorecon.
>
> >>  ')
> >> --
> >> selinux mailing list
> >> selinux(a)lists.fedoraproject.org
> >> https://admin.fedoraproject.org/mailman/listinfo/selinux
> >
> >  -----BEGIN PGP SIGNATURE-----
> >  Version: GnuPG v2.0.16 (GNU/Linux)
> >  Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/
> >
> >  iEYEARECAAYFAk2U4ekACgkQMlxVo39jgT8avgCfeNgVrZclMYWLacP4LNSgXtXy
> >  TRQAn0WgGcTZVO+1gceaJ9VygsrnvlGN
> >  =PKt6
> >  -----END PGP SIGNATURE----- 
>  --
>  selinux mailing list
>  selinux(a)lists.fedoraproject.org
>  https://admin.fedoraproject.org/mailman/listinfo/selinux
>