V4L/DVB (11711): gspca - main: Fix a crash when no bandwidth available

When the bandwidth is not wide enough, the transfer endpoint may be set to
the one of the alternate setting 0. This one may be null and this causes a
divide by 0 oops.

Reported-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index 873e95580407a8479287ff020495c5ee8d340dcc..efa4dd349f608256e819d32c31223d6c75c18ca7 100644 (file)
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -449,7 +449,8 @@ static struct usb_host_endpoint *alt_xfer(struct usb_host_interface *alt,
        for (i = 0; i < alt->desc.bNumEndpoints; i++) {
                ep = &alt->endpoint[i];
                attr = ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
-               if (attr == xfer)
+               if (attr == xfer
+                   && ep->desc.wMaxPacketSize != 0)
                        return ep;
        }
        return NULL;