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From:   Sasha Levin <sashal@kernel.org>
To:     stable@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>,
        Enrico Mioso <mrkiko.rs@gmail.com>,
        Christian Panton <christian@panton.org>,
        "David S . Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.9 59/98] net: cdc_ncm: GetNtbFormat endian fix
Date:   Thu, 25 Oct 2018 10:13:44 -0400
Message-Id: <20181025141423.213774-59-sashal@kernel.org>
In-Reply-To: <20181025141423.213774-1-sashal@kernel.org>
References: <20181025141423.213774-1-sashal@kernel.org>
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From: Bjørn Mork <bjorn@mork.no>

[ Upstream commit 6314dab4b8fb8493d810e175cb340376052c69b6 ]

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: 2b02c20ce0c2 ("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: Sasha Levin <sashal@kernel.org>
---
 drivers/net/usb/cdc_ncm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 3086cae62fdc..7b158674ceed 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -772,7 +772,7 @@ 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)
@@ -890,7 +890,7 @@ 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
-- 
2.17.1