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Sender: Vincent Mailhol <vincent.mailhol@gmail.com>
From:   Vincent Mailhol <mailhol.vincent@wanadoo.fr>
To:     Marc Kleine-Budde <mkl@pengutronix.de>, linux-can@vger.kernel.org
Cc:     Wolfgang Grandegger <wg@grandegger.com>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Frank Jungclaus <frank.jungclaus@esd.eu>, socketcan@esd.eu,
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        =?UTF-8?q?Stefan=20M=C3=A4tje?= <stefan.maetje@esd.eu>,
        Hangyu Hua <hbh25y@gmail.com>,
        Oliver Hartkopp <socketcan@hartkopp.net>,
        Peter Fink <pfink@christ-es.de>,
        Jeroen Hofstee <jhofstee@victronenergy.com>,
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        John Whittington <git@jbrengineering.co.uk>,
        Vasanth Sadhasivan <vasanth.sadhasivan@samsara.com>,
        Jimmy Assarsson <extja@kvaser.com>,
        Anssi Hannula <anssi.hannula@bitwise.fi>,
        Pavel Skripkin <paskripkin@gmail.com>,
        Stephane Grosjean <s.grosjean@peak-system.com>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        "Gustavo A . R . Silva" <gustavoars@kernel.org>,
        Julia Lawall <Julia.Lawall@inria.fr>,
        Dongliang Mu <dzm91@hust.edu.cn>,
        Sebastian Haas <haas@ems-wuensche.com>,
        Maximilian Schneider <max@schneidersoft.net>,
        Daniel Berglund <db@kvaser.com>,
        Olivier Sobrie <olivier@sobrie.be>,
        =?UTF-8?q?Remigiusz=20Ko=C5=82=C5=82=C4=85taj?= 
        <remigiusz.kollataj@mobica.com>,
        Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>,
        Martin Elshuber <martin.elshuber@theobroma-systems.com>,
        Philipp Tomsich <philipp.tomsich@theobroma-systems.com>,
        Bernd Krumboeck <b.krumboeck@gmail.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Alan Stern <stern@rowland.harvard.edu>,
        linux-usb@vger.kernel.org,
        Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Subject: [PATCH 4/8] can: kvaser_usb: kvaser_usb_disconnect(): fix NULL pointer dereference
Date:   Sat,  3 Dec 2022 22:31:55 +0900
Message-Id: <20221203133159.94414-5-mailhol.vincent@wanadoo.fr>
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kvaser_usb sets the usb_interface to NULL before waiting for the
completion of outstanding urbs. This can result in NULL pointer
dereference, c.f. [1] and [2].

Remove the call to usb_set_intfdata(intf, NULL). The core will take
care of setting it to NULL after kvaser_usb_disconnect() at [3].

[1] commit 27ef17849779 ("usb: add usb_set_intfdata() documentation")
Link: https://git.kernel.org/gregkh/usb/c/27ef17849779

[2] thread about usb_set_intfdata() on linux-usb mailing.
Link: https://lore.kernel.org/linux-usb/Y4OD70GD4KnoRk0k@rowland.harvard.edu/

[3] function usb_unbind_interface() from drivers/usb/core/driver.c
Link: https://elixir.bootlin.com/linux/v6.0/source/drivers/usb/core/driver.c#L497

Fixes: 080f40a6fa28 ("can: kvaser_usb: Add support for Kvaser CAN/USB devices")
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
@stable team: the function was moved from kvaser_usb.c to
kvaser_usb_core.c in:

  7259124eac7d1 ("can: kvaser_usb: Split driver into kvaser_usb_core.c and kvaser_usb_leaf.c")
---
 drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
index 3a2bfaad1406..dad916b3288e 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
@@ -981,8 +981,6 @@ static void kvaser_usb_disconnect(struct usb_interface *intf)
 {
 	struct kvaser_usb *dev = usb_get_intfdata(intf);
 
-	usb_set_intfdata(intf, NULL);
-
 	if (!dev)
 		return;
 
-- 
2.37.4