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On 07/31/2013 12:55 PM, Bram Mertens wrote:
Hi,
I have just lost several hours trying to figure out why I was unable to
deploy a file from a configuration channel in our satellite server to a
RHEL6 box while it deployed perfectly to a RHEL5 box.
I finally tracked it down to the fact that the user context was set to
unconfined_u while the rest of the context was set correctly.
On RHEL5 rhncfg-client get worked flawlessly and deployed the file with a
*different* user context (system_u) without complaining. On RHEL6
chncfg-client crashed complaining about the SElinux context - which
differed only in the user context.
Here's what I found (I also posted this as a follow up on the rhn-satellite
mailing list):
I see some very strange behaviour of SELinux on this RHEL6 box.
on RHEL5 the following works as expected:
The default SELinux security context for /etc/sssd/sssd.conf is:
[mertensb@testadintegration01 ~]$ sudo /usr/sbin/matchpathcon
/etc/sssd/sssd.conf /etc/sssd/sssd.conf system_u:object_r:etc_t
Which is also what is currently applied: [mertensb@testadintegration01 ~]$
sudo ls -lZ /etc/sssd/sssd.conf -rw------- root root
system_u:object_r:etc_t /etc/sssd/sssd.conf
So matchpathcon is able to verify the context.
[mertensb@testadintegration01 ~]$ sudo /usr/sbin/matchpathcon -V
/etc/sssd/sssd.conf /etc/sssd/sssd.conf verified.
Testing a randomn other file to verify that matchpathcon works:
[mertensb@testadintegration01 ~]$ touch /tmp/proftpd
[mertensb@testadintegration01 ~]$ sudo ls -lZ /tmp/proftpd -rw-rw-r--
mertensb mertensb user_u:object_r:tmp_t /tmp/proftpd
[mertensb@testadintegration01 ~]$ sudo mv /tmp/proftpd
/etc/cron.monthly/proftpd [mertensb@testadintegration01 ~]$ sudo ls -lZ
/etc/cron.monthly/proftpd -rw-rw-r-- mertensb mertensb
user_u:object_r:tmp_t /etc/cron.monthly/proftpd
[mertensb@testadintegration01 ~]$ sudo /usr/sbin/matchpathcon
/etc/cron.monthly/proftpd /etc/cron.monthly/proftpd
system_u:object_r:ftpd_exec_t [mertensb@testadintegration01 ~]$ sudo
/usr/sbin/matchpathcon -V /etc/cron.monthly/proftpd
/etc/cron.monthly/proftpd has context user_u:object_r:tmp_t, should be
system_u:object_r:ftpd_exec_t
But on the RHEL6 machine I get: [mertensb@defrltot002 ~]$ sudo ls -lZ
/etc/sssd/sssd.conf -rw-------. root root unconfined_u:object_r:etc_t:s0
/etc/sssd/sssd.conf [mertensb@defrltot002 ~]$ sudo /usr/sbin/matchpathcon
/etc/sssd/sssd.conf /etc/sssd/sssd.conf system_u:object_r:etc_t:s0
[mertensb@defrltot002 ~]$ sudo /usr/sbin/matchpathcon -V
/etc/sssd/sssd.conf /etc/sssd/sssd.conf verified.
Repeating my test of matchpathcon: [mertensb@defrltot002 ~]$ touch
/tmp/proftpd [mertensb@defrltot002 ~]$ sudo mv /tmp/proftpd
/etc/cron.monthly/proftpd [mertensb@defrltot002 ~]$ sudo ls -lZ
/etc/cron.monthly/proftpd -rw-r--r--. mertensb ISOP
unconfined_u:object_r:user_ tmp_t:s0 /etc/cron.monthly/proftpd
[mertensb@defrltot002 ~]$ sudo /usr/sbin/matchpathcon
/etc/cron.monthly/proftpd /etc/cron.monthly/proftpd
system_u:object_r:ftpd_exec_t:s0 [mertensb@defrltot002 ~]$ sudo
/usr/sbin/matchpathcon -V /etc/cron.monthly/proftpd
/etc/cron.monthly/proftpd has context unconfined_u:object_r:user_tmp_t:s0,
should be system_u:object_r:ftpd_exec_t:s0
Both have the same sssd SELinux policy loaded: RHEL5:
[mertensb@testadintegration01 ~]$ sudo /usr/sbin/semodule -l|grep sssd sssd
1.0.2 RHEL6: [mertensb@defrltot002 ~]$ sudo /usr/sbin/semodule -l|grep
sssd sssd 1.0.2
Digging further I found out that if only the user context is different
matchpathcon returns OK. See
http://manpages.ubuntu.com/manpages/karmic/man3/matchpathcon.3.html
I also found a post on this list indicating that restorecon has a forece
option to make it set the user context which it doesn't do by default:
http://fedora.12.x6.nabble.com/restorecon-isn-t-restoring-what-matchpathc...
So why isn't the user context set/reset by default? After all it clearly
leaves the system in a broken state.
And why doesn't matchpathcon have a similar force option to make it check
the entire context?
Thanks in advance.
Bram Mertens -- selinux mailing list selinux(a)lists.fedoraproject.org
https://admin.fedoraproject.org/mailman/listinfo/selinux
Well the user component is ignored on almost every SELinux System and all that
are shipped with policy from Red Hat.
The first couple of paragraphs of
http://danwalsh.livejournal.com/63586.html
explain this.
restorecon main goal is to fix the "type" portion of the SELinux label and not
to touch the User component or the MLS field unless you specify -F.
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