RE: [PATCH] printk: introduce kptr_restrict level 3

From: Roberts, William C
Date: Fri Oct 07 2016 - 10:21:16 EST


> As a _singlular_ argument, "it's for out-of-tree code" is weak. As an _additional_
> argument, it has value. Saying "this only helps out-of-tree code" doesn't carry
> much weight. Saying "this helps kernel security, even for out-of-tree code" is
> perfectly valid. And a wrinkle in this is that some day, either that out-of-tree
> code, or brand new code, will land in the kernel, and we don't want to continue
> to require authors be aware of an opt-in security feature. The kernel should
> protect itself (and all of itself, including out-of-tree or future code) by default.

I should have made this more clear in my message, this was in my head and I assumed
that people would just get it. But I shouldn't have made such an assumption.

> And based on my read of this thread, we all appear to be in violent agreement. :)
> "always protect %p" is absolutely the goal, and we can figure out the best way to
> get there.
> -Kees
> --
> Kees Cook
> Nexus Security