watchdog: pcwd_usb: fix NULL-deref at probe

commit 46c319b848268dab3f0e7c4a5b6e9146d3bca8a4 upstream.

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

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/watchdog/pcwd_usb.c b/drivers/watchdog/pcwd_usb.c
index 99ebf6ea3de6..5615f4013924 100644
--- a/drivers/watchdog/pcwd_usb.c
+++ b/drivers/watchdog/pcwd_usb.c
@@ -630,6 +630,9 @@ static int usb_pcwd_probe(struct usb_interface *interface,
                 return -ENODEV;
         }
 
+        if (iface_desc->desc.bNumEndpoints < 1)
+                return -ENODEV;
+
         /* check out the endpoint: it has to be Interrupt & IN */
         endpoint = &iface_desc->endpoint[0].desc;