> > And it probably should be a more reliable method which we probably could > > use to detect !retpolined modules too. > > Andi actually implemented this, but it ended up being watered down > somewhat.
It's enforced in mainline with the following patch It's not fully bullet proof, but should be good enough to protect against mistakes at least. commit 6cfb521ac0d5b97470883ff9b7facae264b7ab12 Author: Andi Kleen <[email protected]> Date: Tue Jan 16 12:52:28 2018 -0800 module: Add retpoline tag to VERMAGIC Add a marker for retpoline to the module VERMAGIC. This catches the case when a non RETPOLINE compiled module gets loaded into a retpoline kernel, making it insecure. It doesn't handle the case when retpoline has been runtime disabled. Even in this case the match of the retcompile status will be enforced. This implies that even with retpoline run time disabled all modules loaded need to be recompiled.
