[PATCH 4.4 17/36] slip: not call free_netdev before rtnl_unlock in slip_open

[Greg Kroah-Hartman]

From: yangerkun <yangerkun@xxxxxxxxxx>

commit f596c87005f7b1baeb7d62d9a9e25d68c3dfae10 upstream.

As the description before netdev_run_todo, we cannot call free_netdev
before rtnl_unlock, fix it by reorder the code.

Signed-off-by: yangerkun <yangerkun@xxxxxxxxxx>
Reviewed-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: Backported to <4.11: free_netdev() is called through sl_free_netdev()]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/slip/slip.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/slip/slip.c
+++ b/drivers/net/slip/slip.c
@@ -867,7 +867,10 @@ err_free_chan:
 	sl->tty = NULL;
 	tty->disc_data = NULL;
 	clear_bit(SLF_INUSE, &sl->flags);
+	/* do not call free_netdev before rtnl_unlock */
+	rtnl_unlock();
 	sl_free_netdev(sl->dev);
+	return err;
 
 err_exit:
 	rtnl_unlock();