Re: [PATCH 1/4] added SECURITY_TIOCSTI_RESTRICT kernel config

[Matt Brown]

On 04/17/2017 02:50 AM, Greg KH wrote:
> On Mon, Apr 17, 2017 at 02:07:03AM -0400, Matt Brown wrote:
> > adding the kernel config SECURITY_TIOCSTI_RESTRICT in order to allow
> > the user to restrict unprivileged command injection using TIOCSTI
> > tty ioctls
>
> "unpriviledged command injection"?  That sounds a bit "odd", don't you
> think?
>
> > Signed-off-by: Matt Brown <matt@xxxxxxxxx>
> > ---
> >  security/Kconfig | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/security/Kconfig b/security/Kconfig
> > index 3ff1bf9..d757bcb 100644
> > --- a/security/Kconfig
> > +++ b/security/Kconfig
> > @@ -18,6 +18,18 @@ config SECURITY_DMESG_RESTRICT
> >
> >  	  If you are unsure how to answer this question, answer N.
> >
> > +config SECURITY_TIOCSTI_RESTRICT
> > +        bool "Restrict unprivileged use of tiocsti command injection"
> > +        default n
> > +        help
> > +	  This enforces restrictions on unprivileged users injecting commands
> > +	  into other processes in the same tty session using the TIOCSTI ioctl
>
> Tabs and spaces?

Sorry about that. Used the wrong vimrc for part of the Kconfig. Will
fix in updated patch.

> Since tty sessions are usually separated by different users, how would
> they have the same one and yet need something like this?
>
> Also, why not put this in the tty config section?
>
> And finally, this patch on its own doesn't do anything :(

I will take your input, update my code, and resubmit as a single
patch.

> thanks,
>
> greg k-h