Re: [PATCH] iio: ad5755: fix off-by-one on devnr limit check

From	Jonathan Cameron <jic23@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] iio: ad5755: fix off-by-one on devnr limit check
Date	2016-08-21 21:40 +0200
Message-ID	<s8GL9-4yb-39@gated-at.bofh.it> (permalink)
References	<rYWRb-2gm-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 25/07/16 23:40, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The comparison for devnr limits is off-by-one, the current check
> allows 0 to AD5755_NUM_CHANNELS and the limit should be in fact
> 0 to AD5755_NUM_CHANNELS - 1.  This can lead to an out of bounds
> write to pdata->dac[devnr]. Fix this by replacing > with >= on the
> comparison.
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
Lars? 

Looks correct to me.

I'd also like a fixes tag for this if possible.  Guessing it
might well be the original driver introduction but best to be
sure ;)

Jonathan
> ---
>  drivers/iio/dac/ad5755.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/dac/ad5755.c b/drivers/iio/dac/ad5755.c
> index 0fde593..5f79682 100644
> --- a/drivers/iio/dac/ad5755.c
> +++ b/drivers/iio/dac/ad5755.c
> @@ -655,7 +655,7 @@ static struct ad5755_platform_data *ad5755_parse_dt(struct device *dev)
>  
>  	devnr = 0;
>  	for_each_child_of_node(np, pp) {
> -		if (devnr > AD5755_NUM_CHANNELS) {
> +		if (devnr >= AD5755_NUM_CHANNELS) {
>  			dev_err(dev,
>  				"There is to many channels defined in DT\n");
>  			goto error_out;
>

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Re: [PATCH] iio: ad5755: fix off-by-one on devnr limit check Jonathan Cameron <jic23@kernel.org> - 2016-08-21 21:40 +0200
  Re: [PATCH] iio: ad5755: fix off-by-one on devnr limit check Lars-Peter Clausen <lars@metafoo.de> - 2016-08-21 22:40 +0200

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