How to make SELinux permissive on a Knox Samsung device? I have a Samsung note 2014 which I rooted following this tutorial. However I now have problems with SELinux which (apparently) is preventing me from installing a Linux virtual box. I backed up and uninstalled KNOX using Titanium backup but still no success. When I type setenforce permissive in a terminal, if get no error message but when I type getenforce, I get "enforcing". 

Is there any way I can change this? The device is running Android 4.3.
You need to open a local terminal shell, by using a "Terminal Emulator" like app. Otherwise you will not get an su'able shell. Since AOS 4.2.2, ADB is not letting you use "su", to get root shell, on stock "Enforced" SELinux devices. 

Then do this:

su 0 setenforce 0


If you need to make this permanent to last between re-boots, you need to find where this is originally set in the various init.*.rc files in boot.img and change it, and reflash... 

EDIT: 2015-09-22

The above trick no longer work on Stock devices using AOS 4.4.4 and above, even with insecure kernels. (Such as those provided by cf-autoroot.) That you can blame Google who made Enforcing permanent. Your only option, other than re-compiling your own ROM, is learning about SEAndroid and context changing using SuperSU's supolicy command to inject the policy files.