Re: [kernel-hardening] Re: [PATCH v7 2/2] security: tty: make TIOCSTI ioctl require CAP_SYS_ADMIN

From: James Morris
Date: Tue May 30 2017 - 22:49:34 EST


On Mon, 29 May 2017, Boris Lukashev wrote:

> With all due respect sir, i believe your review falls short of the
> purpose of this effort - to harden the kernel against flaws in
> userspace.

Which effort? Kernel self protection is about protecting against flaws in
the kernel.

See:
https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project

"This project starts with the premise that kernel bugs have a very long
lifetime, and that the kernel must be designed in ways to protect against
these flaws."

We need to avoid conflating:

- hardening the kernel against attack; and
- modifying the kernel to try and harden userspace.

These patches are the latter, and the case for them is not as
straightforward.


- James
--
James Morris
<jmorris@xxxxxxxxx>