isdn/gigaset: fix NULL-deref at probe

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer should a malicious device lack endpoints.

Fixes: cf7776dc05b8 ("[PATCH] isdn4linux: Siemens Gigaset drivers -
direct USB connection")
Cc: stable <stable@vger.kernel.org>	# 2.6.17
Cc: Hansjoerg Lipp <hjlipp@web.de>

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c
index 11e13c56126f..2da3ff650e1d 100644
--- a/drivers/isdn/gigaset/bas-gigaset.c
+++ b/drivers/isdn/gigaset/bas-gigaset.c
@@ -2317,6 +2317,9 @@ static int gigaset_probe(struct usb_interface *interface,
                 return -ENODEV;
         }
 
+        if (hostif->desc.bNumEndpoints < 1)
+                return -ENODEV;
+
         dev_info(&udev->dev,
                  "%s: Device matched (Vendor: 0x%x, Product: 0x%x)\n",
                  __func__, le16_to_cpu(udev->descriptor.idVendor),