Messages in this thread | | | From | "Tanislav, Cosmin" <> | Subject | RE: [PATCH v2] iio: addac: Do not reference negative array offsets | Date | Thu, 6 Jan 2022 06:31:55 +0000 |
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Reviewed-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Put "iio: addac: ad74413r:" in patch title, maybe?
> -----Original Message----- > From: Kees Cook <keescook@chromium.org> > Sent: Wednesday, January 5, 2022 8:02 PM > To: Lars-Peter Clausen <lars@metafoo.de> > Cc: Kees Cook <keescook@chromium.org>; Hennerich, Michael > <Michael.Hennerich@analog.com>; Tanislav, Cosmin > <Cosmin.Tanislav@analog.com>; Jonathan Cameron <jic23@kernel.org>; > linux-iio@vger.kernel.org; Linus Walleij <linus.walleij@linaro.org>; linux- > kernel@vger.kernel.org; linux-hardening@vger.kernel.org > 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@metafoo.de> > Cc: Michael Hennerich <Michael.Hennerich@analog.com> > Cc: Cosmin Tanislav <cosmin.tanislav@analog.com> > Cc: Jonathan Cameron <jic23@kernel.org> > Cc: linux-iio@vger.kernel.org > Fixes: fea251b6a5db ("iio: addac: add AD74413R driver") > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > v1: > https://urldefense.com/v3/__https://lore.kernel.org/lkml/20211215232321. > 2069314-1- > keescook@chromium.org/__;!!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
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