Re: [PATCH 2/2] fs/sysctl: remove redundant link check in proc_sys_link_fill_cache()

[Danilo Krummrich]

On 2018-02-27 23:59, Kees Cook wrote:
> On Tue, Feb 27, 2018 at 2:43 PM, Danilo Krummrich
> <danilokrummrich@xxxxxxxxxxxxx> wrote:
> > proc_sys_link_fill_cache() does not need to check whether we're
> > called for a link - it's already done by scan().
> >
> > Signed-off-by: Danilo Krummrich <danilokrummrich@xxxxxxxxxxxxx>
> > ---
> >  fs/proc/proc_sysctl.c | 11 +++++------
> >  1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
> > index a0b6c647835e..7e7d9facb842 100644
> > --- a/fs/proc/proc_sysctl.c
> > +++ b/fs/proc/proc_sysctl.c
> > @@ -707,17 +707,16 @@ static bool proc_sys_link_fill_cache(struct file 
> > *file,
> >                                     struct ctl_table *table)
> >  {
> >         bool ret = true;
> > +       int err = 0;
> >         head = sysctl_head_grab(head);
> >
> >         if (IS_ERR(head))
> >                 return false;
> >
> > -       if (S_ISLNK(table->mode)) {
> > -               /* It is not an error if we can not follow the link 
> > ignore it */
> > -               int err = sysctl_follow_link(&head, &table);
> > -               if (err)
> > -                       goto out;
> > -       }
> > +       /* It is not an error if we can not follow the link ignore it 
> > */
> > +       sysctl_follow_link(&head, &table);
>
> Shouldn't this be err = sysctl_follow_link... ? Otherwise I don't see
> where err is used.
>
> -Kees
Of course, thanks.
> > +       if (err)
> > +               goto out;
> >
> >         ret = proc_sys_fill_cache(file, ctx, head, table);
> >  out:
> > --
> > 2.14.1