According to well-known developer Chainfire, the next version of Android could be bringing a change that may end up preventing many of your favorite root apps from working — at least not unless developers implement some kind of fix. Now before you get too up-in-arms, it’s important to note that this latest change is not targeted at root apps and is actually a security improvement.
A recent commit to the Android Open Source Project master tree has been spotted that will prevent apps from extracting files to directories located on the /data partition and then executing them as root. The idea is that this could prevent some malicious programs from executing scripts on the /data partition. It’s currently unclear whether this change will actually make its way into the next version of Android, or if it will be changed by the time Android 4.5 (or whatever they call it) rolls out.
The good news is that even if Android does make this security change, it will be possible for developers to make changes that could still allow most root apps to work, even if there is no one universal ‘fix’ that will work for all apps.
Potential work-arounds (depending on what your app does) include extracting and running from memory or rootfs (mount namespace separation for the win), piping commands directly to su instead of writing to a .sh first (which was a bad practise anyway), forcing a context switch to a non-unconfined domain by way of suparameter or runcon, etc.
So the short-term result could mean that a number of root apps could end up broken if they don’t introduce some kind of workaround in time for the next version of Android. The long-term result is improved security, which is never a bad thing.
In the meantime, it probably wouldn’t hurt to contact your favorite root app developers to ensure they are aware of the issue before the next version of Android hits.