[PATCH 3.13.y-ckt 049/139] USB: cdc-acm: check for valid interfaces

[Kamal Mostafa]

3.13.11-ckt15 -stable review patch.  If anyone has any objections, please let me know.

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

From: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

commit 403dff4e2c94f275e24fd85f40b2732ffec268a1 upstream.

We need to check that we have both a valid data and control inteface for both
types of headers (union and not union.)

References: https://bugzilla.kernel.org/show_bug.cgi?id=83551
Reported-by: Simon Schubert <2+kernel at 0x2c.org>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/class/cdc-acm.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 8a236bf..6746103 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1049,10 +1049,11 @@ next_desc:
 	} else {
 		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
 		data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
-		if (!control_interface || !data_interface) {
-			dev_dbg(&intf->dev, "no interfaces\n");
-			return -ENODEV;
-		}
+	}
+
+	if (!control_interface || !data_interface) {
+		dev_dbg(&intf->dev, "no interfaces\n");
+		return -ENODEV;
 	}
 
 	if (data_interface_num != call_interface_num)
-- 
1.9.1