On Sat, 2021-05-08 at 17:12 +0100, Jonathan Cameron wrote:
> On Fri, 7 May 2021 19:30:41 +0100 Colin King <colin.king@xxxxxxxxxxxxx> wrote:
[]
> > The lux_val returned from tsl2583_get_lux can potentially be zero,
> > so check for this to avoid a division by zero and an overflowed
> > gain_trim_val.
[]
> > Fixes: ac4f6eee8fe8 ("staging: iio: TAOS tsl258x: Device driver")
> > Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> Definitely looks like it could happen so applied to the fixes-togreg branch of
> iio.git and marked for stable.
[]
> > diff --git a/drivers/iio/light/tsl2583.c b/drivers/iio/light/tsl2583.c
[]
> > @@ -341,6 +341,14 @@ static int tsl2583_als_calibrate(struct iio_dev *indio_dev)
> > return lux_val;
> > }
> >
> > + /* Avoid division by zero of lux_value later on */
> > + if (lux_val == 0) {
> > + dev_err(&chip->client->dev,
> > + "%s: lux_val of 0 will produce out of range trim_value\n",
> > + __func__);
> > + return -ENODATA;
> > + }
> > +
> > gain_trim_val = (unsigned int)(((chip->als_settings.als_cal_target)
> > * chip->als_settings.als_gain_trim) / lux_val);
Is a multiplication overflow possible here?
There are also unnecessary parentheses.
