Re: [PATCH 1/7] pipe, sysctl: drop 'min' parameter from pipe-max-size converter

From: Eric Biggers
Date: Tue Jan 09 2018 - 21:30:03 EST


On Tue, Jan 09, 2018 at 02:20:45PM -0800, Kees Cook wrote:
> On Sun, Jan 7, 2018 at 9:35 PM, Eric Biggers <ebiggers3@xxxxxxxxx> wrote:
> > From: Eric Biggers <ebiggers@xxxxxxxxxx>
> >
> > Before validating the given value against pipe_min_size,
> > do_proc_dopipe_max_size_conv() calls round_pipe_size(), which rounds the
> > value up to pipe_min_size. Therefore, the second check against
> > pipe_min_size is redundant. Remove it.
>
> Well, it's not redundant: it provides a hint to anyone trying to tweak
> the sysctl about the minimum value. I think this should stay, but that
> pipe_min_size should be made const.
>
> -Kees
>

It *is* redundant, because it doesn't do anything. round_pipe_size() already
rounds the value up to the minimum.

Eric