usbnet: don't clear urb->dev in tx_complete

URB unlinking is always racing with its completion and tx_complete
may be called before or during running usb_unlink_urb, so tx_complete
must not clear urb->dev since it will be used in unlink path,
otherwise invalid memory accesses or usb device leak may be caused
inside usb_unlink_urb.

Cc: stable@kernel.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index febfdceeb9e5..62f8b5cfbb56 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1037,7 +1037,6 @@ static void tx_complete (struct urb *urb)
         }
 
         usb_autopm_put_interface_async(dev->intf);
-        urb->dev = NULL;
         entry->state = tx_done;
         defer_bh(dev, skb, &dev->txq);
 }