On Sat, 15 Jan 2022 18:12:02 +0000
Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> On Thu, 6 Jan 2022 06:31:55 +0000
> "Tanislav, Cosmin" <Cosmin.Tanislav@xxxxxxxxxx> wrote:
>
> > Reviewed-by: Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx>
> >
> > Put "iio: addac: ad74413r:" in patch title, maybe?
> I can fix that up whilst applying.
Ah. I see you already sent it again. Thanks as that's
even easier.
Jonathan
>
> I'll pick this up after rc1 is out.
>
> Thanks,
>
> Jonathan
>
> >
> > > -----Original Message-----
> > > From: Kees Cook <keescook@xxxxxxxxxxxx>
> > > Sent: Wednesday, January 5, 2022 8:02 PM
> > > To: Lars-Peter Clausen <lars@xxxxxxxxxx>
> > > Cc: Kees Cook <keescook@xxxxxxxxxxxx>; Hennerich, Michael
> > > <Michael.Hennerich@xxxxxxxxxx>; Tanislav, Cosmin
> > > <Cosmin.Tanislav@xxxxxxxxxx>; Jonathan Cameron <jic23@xxxxxxxxxx>;
> > > linux-iio@xxxxxxxxxxxxxxx; Linus Walleij <linus.walleij@xxxxxxxxxx>; linux-
> > > kernel@xxxxxxxxxxxxxxx; linux-hardening@xxxxxxxxxxxxxxx
> > > Subject: [PATCH v2] iio: addac: Do not reference negative array offsets
> > >
> > > [External]
> > >
> > > Instead of aiming rx_buf at an invalid array-boundary-crossing location,
> > > just skip the first increment. Fixes this warning seen when building
> > > with -Warray-bounds:
> > >
> > > drivers/iio/addac/ad74413r.c: In function 'ad74413r_update_scan_mode':
> > > drivers/iio/addac/ad74413r.c:843:22: warning: array subscript -4 is below
> > > array bounds of 'u8[16]' { aka 'unsigned char[16]'} [-Warray-bounds]
> > > 843 | u8 *rx_buf = &st->adc_samples_buf.rx_buf[-1 *
> > > AD74413R_FRAME_SIZE];
> > > |
> > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > drivers/iio/addac/ad74413r.c:84:20: note: while referencing 'rx_buf'
> > > 84 | u8 rx_buf[AD74413R_FRAME_SIZE *
> > > AD74413R_CHANNEL_MAX];
> > > | ^~~~~~
> > >
> > > Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
> > > Cc: Michael Hennerich <Michael.Hennerich@xxxxxxxxxx>
> > > Cc: Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx>
> > > Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
> > > Cc: linux-iio@xxxxxxxxxxxxxxx
> > > Fixes: fea251b6a5db ("iio: addac: add AD74413R driver")
> > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> > > ---
> > > v1:
> > > https://urldefense.com/v3/__https://lore.kernel.org/lkml/20211215232321.
> > > 2069314-1-
> > > keescook@xxxxxxxxxxxx/__;!!A3Ni8CS0y2Y!vadcwdERjyNVz3vFIp5m5S2ms
> > > oFHro8aKzH9ulwPevCKHpev6D53gibZrv5U9mPHGcoB$
> > > v2:
> > > - use "xfer" for checking "first through the loop"
> > > ---
> > > drivers/iio/addac/ad74413r.c | 7 ++++---
> > > 1 file changed, 4 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
> > > index 5271073bb74e..aba9a643a4ca 100644
> > > --- a/drivers/iio/addac/ad74413r.c
> > > +++ b/drivers/iio/addac/ad74413r.c
> > > @@ -840,7 +840,7 @@ static int ad74413r_update_scan_mode(struct iio_dev
> > > *indio_dev,
> > > {
> > > struct ad74413r_state *st = iio_priv(indio_dev);
> > > struct spi_transfer *xfer = st->adc_samples_xfer;
> > > - u8 *rx_buf = &st->adc_samples_buf.rx_buf[-1 *
> > > AD74413R_FRAME_SIZE];
> > > + u8 *rx_buf = st->adc_samples_buf.rx_buf;
> > > u8 *tx_buf = st->adc_samples_tx_buf;
> > > unsigned int channel;
> > > int ret = -EINVAL;
> > > @@ -894,9 +894,10 @@ static int ad74413r_update_scan_mode(struct
> > > iio_dev *indio_dev,
> > >
> > > spi_message_add_tail(xfer, &st->adc_samples_msg);
> > >
> > > - xfer++;
> > > tx_buf += AD74413R_FRAME_SIZE;
> > > - rx_buf += AD74413R_FRAME_SIZE;
> > > + if (xfer != st->adc_samples_xfer)
> > > + rx_buf += AD74413R_FRAME_SIZE;
> > > + xfer++;
> > > }
> > >
> > > xfer->rx_buf = rx_buf;
> > > --
> > > 2.30.2
> >
>
