Hi Ricardo,
Thank you for the patch.
On Tue, Dec 15, 2020 at 04:44:33PM +0100, Ricardo Ribalda wrote:
> Avoid an underflow while calculating the number of inputs for entities
> with zero pads.
>
> Signed-off-by: Ricardo Ribalda <riba...@chromium.org>
> ---
> drivers/media/usb/uvc/uvc_driver.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_driver.c
> b/drivers/media/usb/uvc/uvc_driver.c
> index 9f4451a2e0a6..534629ecd60d 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1033,7 +1033,11 @@ static struct uvc_entity *uvc_alloc_entity(u16 type,
> u16 id,
> unsigned int i;
>
> extra_size = roundup(extra_size, sizeof(*entity->pads));
> - num_inputs = (type & UVC_TERM_OUTPUT) ? num_pads : num_pads - 1;
> + if (num_pads)
> + num_inputs = (type & UVC_TERM_OUTPUT) ? num_pads :
> + num_pads - 1;
This is a weird indentation. How about the following ?
num_inputs = type & UVC_TERM_OUTPUT ? num_pads : num_pads - 1;
I can fix this when applying.
Reviewed-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> + else
> + num_inputs = 0;
> size = sizeof(*entity) + extra_size + sizeof(*entity->pads) * num_pads
> + num_inputs;
> entity = kzalloc(size, GFP_KERNEL);
> @@ -1066,7 +1070,7 @@ static struct uvc_entity *uvc_alloc_entity(u16 type,
> u16 id,
>
> for (i = 0; i < num_inputs; ++i)
> entity->pads[i].flags = MEDIA_PAD_FL_SINK;
> - if (!UVC_ENTITY_IS_OTERM(entity))
> + if (!UVC_ENTITY_IS_OTERM(entity) && num_pads)
> entity->pads[num_pads-1].flags = MEDIA_PAD_FL_SOURCE;
>
> entity->bNrInPins = num_inputs;
--
Regards,
Laurent Pinchart
