[PATCH 4.9 100/164] [media] gspca: konica: add missing endpoint sanity check

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit aa58fedb8c7b6cf2f05941d238495f9e2f29655c upstream.

Make sure to check the number of endpoints to avoid accessing memory
beyond the endpoint array should a device lack the expected endpoints.

Note that, as far as I can tell, the gspca framework has already made
sure there is at least one endpoint in the current alternate setting so
there should be no risk for a NULL-pointer dereference here.

Fixes: b517af722860 ("V4L/DVB: gspca_konica: New gspca subdriver for
konica chipset using cams")

Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Hans Verkuil <hansverk@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/media/usb/gspca/konica.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/media/usb/gspca/konica.c
+++ b/drivers/media/usb/gspca/konica.c
@@ -188,6 +188,9 @@ static int sd_start(struct gspca_dev *gs
 		return -EIO;
 	}
 
+	if (alt->desc.bNumEndpoints < 2)
+		return -ENODEV;
+
 	packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
 
 	n = gspca_dev->cam.cam_mode[gspca_dev->curr_mode].priv;