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

[Matt Brown]

On 05/30/2017 10:48 PM, James Morris wrote:
> 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

I agree that these patches aren't kernel self protection and I don't
believe I have claimed they are such a thing. These patches I'm
presenting are more akin to ptrace protections that are found in Yama.