[PATCH][next] iio: dac: ad5770r: fix off-by-one check on maximum number of channels

[PATCH][next] iio: dac: ad5770r: fix off-by-one check on maximum number of channels

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

Currently there is an off-by-one check on the number of channels that
will cause an arry overrun in array st->output_mode when calling the
function d5770r_store_output_range. Fix this by using >= rather than >
to check for maximum number of channels.

Addresses-Coverity: ("Out-of-bounds access")
Fixes: cbbb819837f6 ("iio: dac: ad5770r: Add AD5770R support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/iio/dac/ad5770r.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/dac/ad5770r.c b/drivers/iio/dac/ad5770r.c
index a98ea76732e7..2d7623b9b2c0 100644
--- a/drivers/iio/dac/ad5770r.c
+++ b/drivers/iio/dac/ad5770r.c
@@ -525,7 +525,7 @@ static int ad5770r_channel_config(struct ad5770r_state *st)
 		ret = fwnode_property_read_u32(child, "num", &num);
 		if (ret)
 			return ret;
-		if (num > AD5770R_MAX_CHANNELS)
+		if (num >= AD5770R_MAX_CHANNELS)
 			return -EINVAL;
 
 		ret = fwnode_property_read_u32_array(child,
-- 
2.25.1

Re: [PATCH][next] iio: dac: ad5770r: fix off-by-one check on maximum number of channels

[Ardelean, Alexandru]

On Fri, 2020-04-03 at 13:58 +0100, Colin King wrote:
> [External]
> 
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently there is an off-by-one check on the number of channels that
> will cause an arry overrun in array st->output_mode when calling the
> function d5770r_store_output_range. Fix this by using >= rather than >
> to check for maximum number of channels.
> 

Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

> Addresses-Coverity: ("Out-of-bounds access")
> Fixes: cbbb819837f6 ("iio: dac: ad5770r: Add AD5770R support")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/iio/dac/ad5770r.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/dac/ad5770r.c b/drivers/iio/dac/ad5770r.c
> index a98ea76732e7..2d7623b9b2c0 100644
> --- a/drivers/iio/dac/ad5770r.c
> +++ b/drivers/iio/dac/ad5770r.c
> @@ -525,7 +525,7 @@ static int ad5770r_channel_config(struct ad5770r_state
> *st)
>  		ret = fwnode_property_read_u32(child, "num", &num);
>  		if (ret)
>  			return ret;
> -		if (num > AD5770R_MAX_CHANNELS)
> +		if (num >= AD5770R_MAX_CHANNELS)
>  			return -EINVAL;
>  
>  		ret = fwnode_property_read_u32_array(child,

Re: [PATCH][next] iio: dac: ad5770r: fix off-by-one check on maximum number of channels

[Jonathan Cameron]

On Fri, 3 Apr 2020 13:26:00 +0000
"Ardelean, Alexandru" <alexandru.Ardelean@analog.com> wrote:

> On Fri, 2020-04-03 at 13:58 +0100, Colin King wrote:
> > [External]
> > 
> > From: Colin Ian King <colin.king@canonical.com>
> > 
> > Currently there is an off-by-one check on the number of channels that
> > will cause an arry overrun in array st->output_mode when calling the
> > function d5770r_store_output_range. Fix this by using >= rather than >
> > to check for maximum number of channels.
> >   
> 
> Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> 
> > Addresses-Coverity: ("Out-of-bounds access")
> > Fixes: cbbb819837f6 ("iio: dac: ad5770r: Add AD5770R support")
> > Signed-off-by: Colin Ian King <colin.king@canonical.com>

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

thanks

Jonathan

> > ---
> >  drivers/iio/dac/ad5770r.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/iio/dac/ad5770r.c b/drivers/iio/dac/ad5770r.c
> > index a98ea76732e7..2d7623b9b2c0 100644
> > --- a/drivers/iio/dac/ad5770r.c
> > +++ b/drivers/iio/dac/ad5770r.c
> > @@ -525,7 +525,7 @@ static int ad5770r_channel_config(struct ad5770r_state
> > *st)
> >  		ret = fwnode_property_read_u32(child, "num", &num);
> >  		if (ret)
> >  			return ret;
> > -		if (num > AD5770R_MAX_CHANNELS)
> > +		if (num >= AD5770R_MAX_CHANNELS)
> >  			return -EINVAL;
> >  
> >  		ret = fwnode_property_read_u32_array(child,