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 <ribalda@xxxxxxxxxxxx> > --- > 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.pinchart@xxxxxxxxxxxxxxxx> > + 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
