# KDM dies after loading MAC mls module



## Steve Taw (Apr 19, 2015)

I installed fbsdFreeBSD-10.1 VM using VMware WS and later installed KDM - all working fine. I then load mac_biba(4) & mac_mls(4) kernel modules. With mac_biba(4) alone, there is no problem. But after adding mac_mls(4), X server dies with a message indicating 'invalid screen 0'. All X files are labelled biba/high and mls/low. I tried with X to biba/equal & mls/equal - but it started & screen went black. Any gives?


----------



## junovitch@ (Apr 19, 2015)

Not experienced with this in particular but I wonder how much this still applies today:
https://lists.freebsd.org/pipermail/freebsd-security/2003-September/000798.html

I would venture to guess something that it needs access to was overlooked.  X server isn't exactly known for it's security.  Mangling it to run in a highly secure MLS environment would certainly be a challenge.


----------



## Steve Taw (Apr 20, 2015)

Thanks - this did help. Once booted to command line ( because X died):
`# setpmac mls/equal startx`
There were still messages saying can't access to .Xauthority and etc ( I think because they are on mls/low), it proceeded to show traditional X console windows screens - not KDE. Then I started KDE from one of the console windows:
`# startkde`
and it brought up KDE. However, it is not a full featured KDE. Captions of the windows are still X look & feel ( kind of interesting to see how X UI mutated into KDE). Opening a new window would be prompted with X grid that I need to place on the desktop and click. User runs with mls/equal. All previous KDE settings are not there anymore - perhaps due to access rights issue with config files. Users can't see full KDE default panel. Only root can access full KDE panel. I guess more exploration and tuning required to boot up directly to KDE as per normal.


----------

