Andy Warner wrote:
Justin Mattock wrote:
On Wed, Nov 5, 2008 at 7:33 AM, Andy Warner <warner@xxxxxxxxx> wrote:
I am using Fedora 9 with the MLS policy. I have been using it in permissive
mode for a while (integrating SELinux with a DBMS and its objects) and now
must do some work/testing in enforcing mode. As soon as I switch to
enforcing mode I seem unable to perform any action which requires privilege.
What is the anticipated method to shutdown/reboot the system and to toggle
the enforcing mode while in MLS/Enforcing? What I assumed was to transition
to an appropriate role (sysadm_r and secadm_r respectively) and then issue
the corresponding command (shutdown and setenforce). This fails and I
believe my difficulty is that in both cases I need to also be the linux root
user. There does not seem to be an obvious way to execute a command as the
lunux root user as neither su nor sudo seem available while in the sysadm_r
and secadm_r roles. Executing something like seaudit while in the auditadm_r
role fails to allow me to authenticate as root. Despite being the correct
password it continuously loops asking for the password.
As a related but less important question, in general, is it intended that a
user initially have the staff_r role upon login and then transition to a
more trusted role (i.e., secadm_r) using the newrole command? (as opposed to
having the secadm_r upon login.
Thanks for any help,
Andy
Not sure how red hat works,
but for me using ubuntu having to change roles
I first needed to collect all of the allow rules, i.g.
allow newrole_t staff_t:process etc...
then after after a reboot into enforce mode
using newrole -r works fine.(just haven't defined secadm_r yet).
As for toggling from enforce to permissive
using setenforce 0 or 1
or echo 0/1 > /selinux/enforce.
I have no problem changing to a role while in enforcing mode, the
problem is in performing the command. Here is what is happening (the
following was executed while in enforcing mode):
[staff@oak ~]$ id -Z
staff_u:staff_r:staff_t:SystemLow:SystemLow-SystemHigh
[staff@oak ~]$ newrole -r secadm_r
Password:
[staff@oak ~]$ id -Z
staff_u:secadm_r:secadm_t:SystemLow:SystemLow-SystemHigh
[staff@oak ~]$ ls -l /selinux/enforce
-rw-r--r-- 1 root root 0 2008-11-05 17:08 /selinux/enforce
[staff@oak ~]$ /usr/sbin/setenforce 1
/usr/sbin/setenforce: setenforce() failed
[staff@oak ~]$ sudo /usr/sbin/setenforce 1
sudo: setresuid(ROOT_UID, 1, ROOT_UID): Operation not permitted
[staff@oak ~]$ id
uid=503(staff) gid=500(user) groups=500(user)
context=staff_u:secadm_r:secadm_t:SystemLow:SystemLow-SystemHigh
[staff@oak ~]$
As can be seen I can transition to the secadm_r without an issue. And,
from the DAC modes of /selinux/enforce I would guess it requires linux
root to be written. Also, I thought I read elsewhere that the secadm_r
was configured so that it could not perform an su/sudo. Likewise, if I
try to execute system-config-selinux as the secadm_r role, I am not
permitted to authenticate as linux root user so I am not able to do
anything. If selinux is in permissive mode everything works, as long as
I su/sudo to root first. I have similar issues with the auditadm_r role.
As for my previously mentioned issue with using sysadm_r to issue a
shutdown command while in enforcing mode, I was mistaken and this is
possible using sudo (not sure what I was thinking). It seems no MLS
roles can use su, only staff_r and sysadm_r may use sudo. auditadm_r
and secadm_r cannot use either and seem powerless without it. I am also
unable to directly log in as root when in enforcing mode.
Note that I am using the roles as they are configured in the MLS
policy. If it is required to change or configure the roles to make them
able do what it seems like they should be able to do, thats ok, but
first I need to make sure I'm not just being boneheaded and using them
in the wrong way or have bad expectations of what they should be able
to do.
Sorry to answer my own email, but just to button this up. I could not
log into my root account because of a conflict between the staff_t
(login process type) and the admin_home_t (root's home dir file type).
Any attempt to start a session for root during enforcing mode would die
as it could not access root's home directory. I am not exactly sure why
policy is this way, if I did something or the mls policy is that way by
default. So, I had to find another way to have linux root and
secadm_r/auditadm_r at the same time. The su and sudo commands are not
available from those roles. So, from the staff_r I had to start a shell
using sudo as:
sudo -s -r secadm_r
This gave me a shell with the linux root user and the secadm_r role and
I was able to run things like system-config-selinux and setenforce
during enforcing mode. Same applies to auditadm_r. role.
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