[PATCH 3.2 19/95] uwb: i1480-dfu: fix NULL-deref at probe

[Ben Hutchings]

3.2.91-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 4ce362711d78a4999011add3115b8f4b0bc25e8c upstream.

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

Note that the dereference happens in the cmd and wait_init_done
callbacks which are called during probe.

Fixes: 1ba47da52712 ("uwb: add the i1480 DFU driver")
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@xxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/uwb/i1480/dfu/usb.c | 3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/uwb/i1480/dfu/usb.c
+++ b/drivers/uwb/i1480/dfu/usb.c
@@ -362,6 +362,9 @@ int i1480_usb_probe(struct usb_interface
 				 result);
 	}
 
+	if (iface->cur_altsetting->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	result = -ENOMEM;
 	i1480_usb = kzalloc(sizeof(*i1480_usb), GFP_KERNEL);
 	if (i1480_usb == NULL) {