[PATCH] drivers/iio/adc/ad7124.c: fix division by zero in ad7124_set_channel_odr()

[PATCH] drivers/iio/adc/ad7124.c: fix division by zero in ad7124_set_channel_odr()

[Zicheng Qu]

In the ad7124_write_raw() function, parameter val can potentially
be zero. This may lead to a division by zero when DIV_ROUND_CLOSEST()
is called within ad7124_set_channel_odr(). The ad7124_write_raw()
function is invoked through the sequence: iio_write_channel_raw() ->
iio_write_channel_attribute() -> iio_channel_write(), with no checks
in place to ensure val is non-zero.

Cc: stable@vger.kernel.org
Fixes: 7b8d045e497a ("iio: adc: ad7124: allow more than 8 channels")
Signed-off-by: Zicheng Qu <quzicheng@huawei.com>
---
 drivers/iio/adc/ad7124.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
index a5d91933f505..b79c48d46ccc 100644
--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -637,7 +637,7 @@ static int ad7124_write_raw(struct iio_dev *indio_dev,
 
 	switch (info) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		if (val2 != 0) {
+		if (val2 != 0 || val == 0) {
 			ret = -EINVAL;
 			break;
 		}
-- 
2.34.1

Re: [PATCH] drivers/iio/adc/ad7124.c: fix division by zero in ad7124_set_channel_odr()

[Nuno Sá]

On Tue, 2024-10-22 at 13:43 +0000, Zicheng Qu wrote:
> In the ad7124_write_raw() function, parameter val can potentially
> be zero. This may lead to a division by zero when DIV_ROUND_CLOSEST()
> is called within ad7124_set_channel_odr(). The ad7124_write_raw()
> function is invoked through the sequence: iio_write_channel_raw() ->
> iio_write_channel_attribute() -> iio_channel_write(), with no checks
> in place to ensure val is non-zero.
> 
> Cc: stable@vger.kernel.org
> Fixes: 7b8d045e497a ("iio: adc: ad7124: allow more than 8 channels")
> Signed-off-by: Zicheng Qu <quzicheng@huawei.com>
> ---

LGTM,

Reviewed-by: Nuno Sa <nuno.sa@analog.com>

>  drivers/iio/adc/ad7124.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
> index a5d91933f505..b79c48d46ccc 100644
> --- a/drivers/iio/adc/ad7124.c
> +++ b/drivers/iio/adc/ad7124.c
> @@ -637,7 +637,7 @@ static int ad7124_write_raw(struct iio_dev *indio_dev,
>  
>  	switch (info) {
>  	case IIO_CHAN_INFO_SAMP_FREQ:
> -		if (val2 != 0) {
> +		if (val2 != 0 || val == 0) {
>  			ret = -EINVAL;
>  			break;
>  		}

Re: [PATCH] drivers/iio/adc/ad7124.c: fix division by zero in ad7124_set_channel_odr()

[Jonathan Cameron]

On Tue, 22 Oct 2024 16:23:17 +0200
Nuno Sá <noname.nuno@gmail.com> wrote:

> On Tue, 2024-10-22 at 13:43 +0000, Zicheng Qu wrote:
> > In the ad7124_write_raw() function, parameter val can potentially
> > be zero. This may lead to a division by zero when DIV_ROUND_CLOSEST()
> > is called within ad7124_set_channel_odr(). The ad7124_write_raw()
> > function is invoked through the sequence: iio_write_channel_raw() ->
> > iio_write_channel_attribute() -> iio_channel_write(), with no checks
> > in place to ensure val is non-zero.
> > 
> > Cc: stable@vger.kernel.org
> > Fixes: 7b8d045e497a ("iio: adc: ad7124: allow more than 8 channels")
> > Signed-off-by: Zicheng Qu <quzicheng@huawei.com>
> > ---  
> 
> LGTM,
> 
> Reviewed-by: Nuno Sa <nuno.sa@analog.com>
As with the other patch, I fixed up the patch title to match local style.

Applied to the fixes-togreg branch of iio.git

Thanks,

Jonathan

> 
> >  drivers/iio/adc/ad7124.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
> > index a5d91933f505..b79c48d46ccc 100644
> > --- a/drivers/iio/adc/ad7124.c
> > +++ b/drivers/iio/adc/ad7124.c
> > @@ -637,7 +637,7 @@ static int ad7124_write_raw(struct iio_dev *indio_dev,
> >  
> >  	switch (info) {
> >  	case IIO_CHAN_INFO_SAMP_FREQ:
> > -		if (val2 != 0) {
> > +		if (val2 != 0 || val == 0) {
> >  			ret = -EINVAL;
> >  			break;
> >  		}  
>