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

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

[Colin King]

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++)
-- 
2.20.1

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

[Sa, Nuno]

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

[Jonathan Cameron]

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.

Thanks,

Jonathan

> Thanks,
> Nuno Sá

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

[Jonathan Cameron]

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  
>