From 5660493c637c9d83786f1c9297f403eae44177b6 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Tue, 10 Dec 2019 12:32:30 +0100
Subject: [PATCH] can: kvaser_usb: fix interface sanity check
Git-commit: 5660493c637c9d83786f1c9297f403eae44177b6
Patch-mainline: v5.5-rc6
References: git-fixes

Make sure to use the current alternate setting when verifying the
interface descriptors to avoid binding to an invalid interface.

Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.

Fixes: aec5fb2268b7 ("can: kvaser_usb: Add support for Kvaser USB hydra family")
Cc: stable <stable@vger.kernel.org>     # 4.19
Cc: Jimmy Assarsson <extja@kvaser.com>
Cc: Christer Beskow <chbe@kvaser.com>
Cc: Nicklas Johansson <extnj@kvaser.com>
Cc: Martin Henriksson <mh@kvaser.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 2 +-
 drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
index 5fc0be564274..7ab87a758754 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
@@ -1590,7 +1590,7 @@ static int kvaser_usb_hydra_setup_endpoints(struct kvaser_usb *dev)
 	struct usb_endpoint_descriptor *ep;
 	int i;
 
-	iface_desc = &dev->intf->altsetting[0];
+	iface_desc = dev->intf->cur_altsetting;
 
 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 		ep = &iface_desc->endpoint[i].desc;
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
index ae4c37e1bb75..1b9957f12459 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
@@ -1310,7 +1310,7 @@ static int kvaser_usb_leaf_setup_endpoints(struct kvaser_usb *dev)
 	struct usb_endpoint_descriptor *endpoint;
 	int i;
 
-	iface_desc = &dev->intf->altsetting[0];
+	iface_desc = dev->intf->cur_altsetting;
 
 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 		endpoint = &iface_desc->endpoint[i].desc;
-- 
2.16.4