[PATCH 3.16 029/134] [media] gspca: konica: add missing endpoint sanity check

Ben Hutchings
2017-08-18T13:15:43Z

From: Johan Hovold <johan@kernel.org>

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@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
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;