Re: SELinux, NIS, NFS, and /home, trouble with Fedora 18 converting user_home_dir_t to detault_t

Tue May 28 17:42:09 UTC 2013

For reasons I don't understand, the install labelled /home with (I think, I'm offsite with no access) auto_fs_t as it is a mount point for autofs.

Roland
--
Roland Roberts,  PhD
6818 Madeline Court
Brooklyn,  NY 11220

-------- Original message --------
From: Daniel J Walsh <dwalsh at redhat.com> 
Date: 05/28/2013  8:33 AM  (GMT-05:00) 
To: Roland Roberts <roland at astrofoto.org> 
Cc: Dominick Grift <dominick.grift at gmail.com>,selinux at lists.fedoraproject.org 
Subject: Re: SELinux, NIS, NFS, and /home, trouble with Fedora 18 converting
   user_home_dir_t to detault_t 

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On 05/28/2013 08:03 AM, Roland Roberts wrote:
> Yet normally /home is home_root_t. And in my case /data is a mount point
> for other things; the actual disk is mounted at /data/home, so I thought I
> was doing the equivalent of what the man page says.
> 
> Roland -- Roland Roberts,  PhD 6818 Madeline Court Brooklyn,  NY 11220
> 
> 
> 
> -------- Original message -------- From: Dominick Grift
> <dominick.grift at gmail.com> Date: 05/28/2013 4:13 AM (GMT-05:00) To: Roland
> Roberts <roland at astrofoto.org> Cc: selinux at lists.fedoraproject.org Subject:
> Re: SELinux, NIS, NFS, and /home, trouble with Fedora 18 converting 
> user_home_dir_t to detault_t
> 
> 
> On Mon, 2013-05-27 at 19:01 -0400, Roland Roberts wrote:
> 
> SELinux contexts for /home are treated a bit differently than other 
> locations.
> 
> Try instead: (from: man semanage):
> 
>> For home directories under top level directory, for example /disk6/home, 
>> execute the following commands. # semanage fcontext -a -t home_root_t
>> "/disk6" # semanage fcontext -a -e /home /disk6/home # restorecon -R -v
>> /disk6
> 
> 
>> I'm trying to clean up selinux contexts and having trouble. The system is
>> a new install of Fedora 18, but the home directories have been preserved
>> for a long time. Because the system runs boot on raid-1, it was installed
>> as Fedora 17 and then I used fedup to move to Fedora 18.
>> 
>> My home directories are automounted via NFS and an NIS map. I mount them 
>> on the clients with an explicit context:
>> 
>> 270 roland> ypcat auto.home 
>> -rw,soft,intr,tcp,context="system_u:object_r:user_home_t:s0" 
>> archos.rlent.pnet:/data/home/&
>> 
>> However, my troubles right now are confined to the server.
>> 
>> The real home directory is /data/home so /data/home/roland is mounted on 
>> /home/roland. All clients see the same mount point, even the server 
>> remounts this way.
>> 
>> Most of the selinux context information is wrong, probably because some 
>> of these files have been hanging around roughly since RedHat 3.0.3. Yes, 
>> really. Although the content has surely changed (e.g., .bashrc).
>> 
>> To get started, I've done this
>> 
>> semanage fcontext -a -t home_root_t /data/home semanage fcontext -a -t
>> user_home_dir_t '/data/home/(.*)' semanage fcontext -a -t lost_found_t
>> /data/home/lost+found restorecon -v -R /data/home
>> 
>> That gave the surprising result of doing absolutely nothing. So I 
>> brute-forced it and did
>> 
>> semanage fcontext -a -t home_root_t /data/home semanage fcontext -a -t
>> lost_found_t /data/home/lost+found for D in $LIST; do semanage fcontext
>> -a -t user_home_dir_t /data/home/$D; done restorecon -v -R /data/home
>> 
>> The above did not work for the lost+found directory. I haven't figured 
>> out why. I tried deleting all the contexts I had set and starting over 
>> and I tried setting the context just on lost+found repeatedly to no 
>> avail. lost+found remains default_t.
>> 
>> Next, I log in via ssh to my user account. Since I have X forwarding 
>> turned on, this results in an .Xauthority file being created. If I run 
>> (as root, from another window) restorecon, I get this
>> 
>> [root at archos ~]# cd /data/home/roland [root at archos roland]# restorecon -v
>> -R /data/home/roland restorecon reset /data/home/roland/.Xauthority
>> context 
>> unconfined_u:object_r:xauth_home_t:s0->unconfined_u:object_r:default_t:s0
>>
>>
>> 
So the file was created with the correct context, but it gets zapped
>> with restorecon. I can create a new file via touch and it gets created 
>> with the correct context
>> 
>> 268 roland> ls -Z foo -rw-rw-r--. roland roland
>> unconfined_u:object_r:user_home_t:s0 foo 269 roland> ls -Zad . 
>> drwxr-xr-x. roland roland system_u:object_r:user_home_dir_t:s0 .
>> 
>> But again, if I run restorecon, it gets converted to default_t.
>> 
>> I realize the whole NIS/NFS thing makes this problematic on the clients, 
>> but all of the above is on the server. I was hoping to get the file 
>> contexts fixed up, but even if I can get it to stop converting everything
>> back to default_t, I haven't got a clue about all the other contexts I
>> need to set (e.g., ssh_home_t for .ssh, but what else) and then I fear
>> they will just get reset, too.
>> 
>> So, what's going on here and how do I stop it? Then after that, how do I 
>> go about fixing all the default_t under my home directory to be what they
>> should be.
>> 
>> roland
>> 
> 
> 
> 
> 
> -- selinux mailing list selinux at lists.fedoraproject.org 
> https://admin.fedoraproject.org/mailman/listinfo/selinux
> 

In this case you want to label /data/home as equivalent to /home
and you probably want to label data with a label that most apps can read like
usr_t.

# semanage fcontext -a -t usr_t '/data(/.*)?'
# semanage fcontext -a -e /home /data/home

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