Re: [PATCH] xfs: mark sb_fname as nonstring

[Eric Sandeen]

On 5/25/18 3:16 PM, Arnd Bergmann wrote:

> On Fri, May 25, 2018 at 6:53 PM, Eric Sandeen <sandeen@xxxxxxxxxx> wrote:
> > On 5/25/18 10:14 AM, Arnd Bergmann wrote:
...

> > > @@ -1860,7 +1860,7 @@ xfs_ioc_setlabel(
> > >          spin_lock(&mp->m_sb_lock);
> > >          memset(sbp->sb_fname, 0, sizeof(sbp->sb_fname));
> > > -       strncpy(sbp->sb_fname, label, sizeof(sbp->sb_fname));
> > > +       memcpy(sbp->sb_fname, label, len);
> >
> >
> > Hm but len = strnlen(label, XFSLABEL_MAX + 1);
> > which could be one longer than sbp->sb_fname, no?
>
> We have an explicit check for that, so I think it's ok:
>
>          if (len > sizeof(sbp->sb_fname))
>                  return -EINVAL;

Ah so we do; I wrote this at least 2 weeks ago, you're asking a lot for
me to remember it.  (or to even read it, apparently).   ;)

Thanks,
-Eric