Re: [PATCH] iio:core: Fix bug in length of event info_mask and catch unhandled bits set in masks.

[Ardelean, Alexandru]

On Tue, 2019-06-04 at 20:40 +0800, Young Xiao wrote:
> [External]
> 
> 
> The incorrect limit for the for_each_set_bit loop was noticed whilst fixing
> this other case.  Note that as we only have 3 possible entries a the moment
> and the value was set to 4, the bug would not have any effect currently.
> It will bite fairly soon though, so best fix it now.
> 
> See commit ef4b4856593f ("iio:core: Fix bug in length of event info_mask and
> catch unhandled bits set in masks.") for details.
> 
> Signed-off-by: Young Xiao <92siuyang@xxxxxxxxx>

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

Thanks for this patch.
This fix is validated also by the fact that iio_device_add_info_mask_type() has this check on the same iteration.


> ---
>  drivers/iio/industrialio-core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index f5a4581..dd8873a 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1107,6 +1107,8 @@ static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
>         char *avail_postfix;
> 
>         for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
> +               if (i >= ARRAY_SIZE(iio_chan_info_postfix))
> +                       return -EINVAL;
>                 avail_postfix = kasprintf(GFP_KERNEL,
>                                           "%s_available",
>                                           iio_chan_info_postfix[i]);
> --
> 2.7.4
>