Re: [PATCH 7/7] exec: Implement kernel_execve

From: Kees Cook
Date: Wed Jul 15 2020 - 11:00:21 EST


On Wed, Jul 15, 2020 at 07:42:48AM +0100, Christoph Hellwig wrote:
> On Tue, Jul 14, 2020 at 02:49:23PM -0700, Kees Cook wrote:
> > On Tue, Jul 14, 2020 at 08:31:40AM -0500, Eric W. Biederman wrote:
> > > +static int count_strings_kernel(const char *const *argv)
> > > +{
> > > + int i;
> > > +
> > > + if (!argv)
> > > + return 0;
> > > +
> > > + for (i = 0; argv[i]; ++i) {
> > > + if (i >= MAX_ARG_STRINGS)
> > > + return -E2BIG;
> > > + if (fatal_signal_pending(current))
> > > + return -ERESTARTNOHAND;
> > > + cond_resched();
> > > + }
> > > + return i;
> > > +}
> >
> > I notice count() is only ever called with MAX_ARG_STRINGS. Perhaps
> > refactor that too? (And maybe rename it to count_strings_user()?)
>
> Liks this?
>
> http://git.infradead.org/users/hch/misc.git/commitdiff/35a3129dab5b712b018c30681d15de42d9509731

Heh, yes please. :) (Which branch is this from? Are yours and Eric's
tree going to collide?)

--
Kees Cook