>>nroets+(OP)
In the good old days, there were exploits patched years prior by some OEMs that were never upstreamed even to Google. New rooting apps come out and... just doesn't work. I don't know if that still happens, though.
>>nroets+(OP)
Not really.. numerous changes are still not a total redesign of whichever subsystem was affected so it's pretty obvious where some small security relevant changes are. A stupid embargo was always enough to ruin security by code analysis for white hats but never enough to stop attacks by code analysis for black hats.