Re: [PATCH] iio: temperature: ltc2983: fix u32 read into a unsigned long long

Jonathan Cameron
2019-11-16T15:15:33Z

On Sun, 10 Nov 2019 11:48:23 +0000
Jonathan Cameron <jic23@kernel.org> wrote:

> On Wed, 6 Nov 2019 14:19:52 +0000
> "Sa, Nuno" <Nuno.Sa@analog.com> wrote:
>
> > On Tue, 2019-11-05 at 20:28 +0000, Colin King wrote:
> > >
> > > From: Colin Ian King <colin.king@canonical.com>
> > >
> > > Currently the read of temp using of_property_read_u32_index is
> > > reading
> > > a u32 value into a unsigned long long. This relies on machine
> > > endianness
> > > to work correctly, so fix this by reading a u32 value and setting
> > > temp
> > > to this value.
> > >
> > > Addresses-Coverity: ("Reliance on integer endianness")
> > > Fixes: f110f3188e56 ("iio: temperature: Add support for LTC2983")
> > > Signed-off-by: Colin Ian King <colin.king@canonical.com>
> > > ---
> > > drivers/iio/temperature/ltc2983.c | 6 ++++--
> > > 1 file changed, 4 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/iio/temperature/ltc2983.c
> > > b/drivers/iio/temperature/ltc2983.c
> > > index ddf47023364b..d39c0d6b77f1 100644
> > > --- a/drivers/iio/temperature/ltc2983.c
> > > +++ b/drivers/iio/temperature/ltc2983.c
> > > @@ -444,8 +444,10 @@ static struct ltc2983_custom_sensor
> > > *__ltc2983_custom_sensor_new(
> > > else
> > > temp = __convert_to_raw(temp,
> > > resolution);
> > > } else {
> > > - of_property_read_u32_index(np, propname, index,
> > > - (u32 *)&temp);
> > > + u32 t32;
> > > +
> > > + of_property_read_u32_index(np, propname, index,
> > > &t32);
> > > + temp = t32;
> > > }
> > >
> > > for (j = 0; j < n_size; j++)
> >
> > Acked-by: Nuno Sá <nuno.sa@analog.com>
> >
>
> A slight complexity around this one. I'm not sure I'll have time for a pull
> before the merge window (as Greg will only take them to about 1 week before
> that opens so we get some exposure in Linux next).
>
> As a result I'll have to sit on this one until Linus comments on rc7, probably
> later today. Otherwise it'll be material for stable post release.
>
> If I seem to have lost it give me a poke and we'll make sure it goes into
> an early rc instead of at the merge window.
I forgot about it when I sent the final pull request out. Sorry about that,
will have to wait for post merge window.

Applied to the fixes-togreg branch of iio.git.

Thanks,

Jonathan

>
> Thanks,
>
> Jonathan
>
> > Thanks,
> > Nuno Sá
>