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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
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        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Alan Stern <stern@rowland.harvard.edu>,
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        Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Subject: [PATCH 5/8] can: mcba_usb: mcba_usb_disconnect(): fix NULL pointer dereference
Date:   Sat,  3 Dec 2022 22:31:56 +0900
Message-Id: <20221203133159.94414-6-mailhol.vincent@wanadoo.fr>
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mcba_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 mcba_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: 51f3baad7de9 ("can: mcba_usb: Add support for Microchip CAN BUS Analyzer")
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
 drivers/net/can/usb/mcba_usb.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
index 47619e9cb005..a21c1ad4894f 100644
--- a/drivers/net/can/usb/mcba_usb.c
+++ b/drivers/net/can/usb/mcba_usb.c
@@ -890,8 +890,6 @@ static void mcba_usb_disconnect(struct usb_interface *intf)
 {
 	struct mcba_priv *priv = usb_get_intfdata(intf);
 
-	usb_set_intfdata(intf, NULL);
-
 	netdev_info(priv->netdev, "device disconnected\n");
 
 	unregister_candev(priv->netdev);
-- 
2.37.4