USB: idmouse: fix NULL-deref at probe

commit b0addd3fa6bcd119be9428996d5d4522479ab240 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c
index 2975e80..9a67ae3 100644
--- a/drivers/usb/misc/idmouse.c
+++ b/drivers/usb/misc/idmouse.c
@@ -346,6 +346,9 @@
 	if (iface_desc->desc.bInterfaceClass != 0x0A)
 		return -ENODEV;
 
+	if (iface_desc->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	/* allocate memory for our device state and initialize it */
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 	if (dev == NULL)