can: mcba_usb: fix use-after-free on disconnect

BugLink: https://bugs.launchpad.net/bugs/1853519
commit 4d6636498c41891d0482a914dd570343a838ad79 upstream.

The driver was accessing its driver data after having freed it.

Fixes: 51f3baad7de9 ("can: mcba_usb: Add support for Microchip CAN BUS Analyzer")
Cc: stable <stable@vger.kernel.org>     # 4.12
Cc: Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>
Reported-by: syzbot+e29b17e5042bbc56fae9@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
index 8d8c2086424d09b2c93a377be756dead26dc7979..1b0afeaf1a3c22ee3911635f0e2d2a464b51ed7f 100644 (file)
--- a/drivers/net/can/usb/mcba_usb.c
+++ b/drivers/net/can/usb/mcba_usb.c
@@ -887,9 +887,8 @@ static void mcba_usb_disconnect(struct usb_interface *intf)
        netdev_info(priv->netdev, "device disconnected\n");
 
        unregister_candev(priv->netdev);
-       free_candev(priv->netdev);
-
        mcba_urb_unlink(priv);
+       free_candev(priv->netdev);
 }
 
 static struct usb_driver mcba_usb_driver = {