[media] gspca: konica: add missing endpoint sanity check

[ Upstream commit aa58fedb8c7b6cf2f05941d238495f9e2f29655c ]

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: stable <stable@vger.kernel.org>     # 2.6.37
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: Sasha Levin <alexander.levin@verizon.com>

diff --git a/drivers/media/usb/gspca/konica.c b/drivers/media/usb/gspca/konica.c
index 39c96bb4c985fce504372d306f96e8fe71ea7775..04972291a5a566e836f17cbe621916901061964e 100644 (file)
--- 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 *gspca_dev)
                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;