On Mon, 7 Jul 2025, Dongsheng Yang wrote:
>
> 在 7/7/2025 6:39 PM, Mikulas Patocka 写道:
> > There's a possible integer overflow in stripe_io_hints if we have too
> > large chunk size. Test if the overflow happened, and if it did, don't set
> > limits->io_min and limits->io_opt;
> >
> > Signed-off-by: Mikulas Patocka <mpato...@redhat.com>
> > Cc: sta...@vger.kernel.org
> >
> > ---
> > drivers/md/dm-stripe.c | 10 +++++++---
> > 1 file changed, 7 insertions(+), 3 deletions(-)
> >
> > Index: linux-2.6/drivers/md/dm-stripe.c
> > ===================================================================
> > --- linux-2.6.orig/drivers/md/dm-stripe.c 2025-07-06 15:02:23.000000000
> > +0200
> > +++ linux-2.6/drivers/md/dm-stripe.c 2025-07-07 12:32:49.000000000
> > +0200
> > @@ -456,10 +456,14 @@ static void stripe_io_hints(struct dm_ta
> > struct queue_limits *limits)
> > {
> > struct stripe_c *sc = ti->private;
> > - unsigned int chunk_size = sc->chunk_size << SECTOR_SHIFT;
> > + unsigned int io_min = sc->chunk_size << SECTOR_SHIFT;
> > + unsigned int io_opt = io_min * sc->stripes;
> > - limits->io_min = chunk_size;
> > - limits->io_opt = chunk_size * sc->stripes;
> > + if (io_min >> SECTOR_SHIFT == sc->chunk_size &&
> > + io_opt / sc->stripes == io_min) {
> > + limits->io_min = io_min;
> > + limits->io_opt = io_opt;
> > + }
>
>
> Hi Mikulas,
>
> What about using check_xxx_overflow() ? something like:
>
>
> if (check_shl_overflow(sc->chunk_size, SECTOR_SHIFT, &io_min))
> return;
>
>
> if (check_mul_overflow(io_min, sc->stripes, &io_opt))
> return;
>
> limits->io_min = io_min;
> limits->io_opt = io_opt;
>
> > }
> > static struct target_type stripe_target = {
> >
> >
Yes, that's a good idea.
I changed the patch to use these macros.
Mikulas
