net: cdc_ncm: GetNtbFormat endian fix

[ Upstream commit 6314dab4 ]

The GetNtbFormat and SetNtbFormat requests operate on 16 bit little
endian values. We get away with ignoring this most of the time, because
we only care about USB_CDC_NCM_NTB16_FORMAT which is 0x0000.  This
fails for USB_CDC_NCM_NTB32_FORMAT.

Fix comparison between LE value from device and constant by converting
the constant to LE.
Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Fixes: 2b02c20c ("cdc_ncm: Set NTB format again after altsetting switch for Huawei devices")
Cc: Enrico Mioso <mrkiko.rs@gmail.com>
Cc: Christian Panton <christian@panton.org>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-By: Enrico Mioso <mrkiko.rs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/usb/cdc_ncm.c

@@ -771,7 +771,7 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
 	int err;
 	u8 iface_no;
 	struct usb_cdc_parsed_header hdr;
-	u16 curr_ntb_format;
+	__le16 curr_ntb_format;
 
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
@@ -889,7 +889,7 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
 			goto error2;
 		}
 
-		if (curr_ntb_format == USB_CDC_NCM_NTB32_FORMAT) {
+		if (curr_ntb_format == cpu_to_le16(USB_CDC_NCM_NTB32_FORMAT)) {
 			dev_info(&intf->dev, "resetting NTB format to 16-bit");
 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
 					       USB_TYPE_CLASS | USB_DIR_OUT