diff mbox series

[v3,3/8] media: uvcvideo: Allow entities with no pads

Message ID 20201119215020.508487-4-ribalda@chromium.org (mailing list archive)
State New, archived
Headers show
Series Show privacy_gpio as a v4l2_ctrl | expand

Commit Message

Ricardo Ribalda Nov. 19, 2020, 9:50 p.m. UTC 
Avoid an underflow while calculating the number of inputs for entities
with zero pads.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_driver.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox series

Patch

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;
+	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;