From acf673a3187edf72068ee2f92f4dc47d66baed47 Mon Sep 17 00:00:00 2001 From: David Miller <davem@davemloft.net> Date: Thu, 17 Dec 2015 16:05:32 -0500 Subject: [PATCH] 6pack: Fix use after free in sixpack_close(). Need to do the unregister_device() after all references to the driver private have been done. Also we need to use del_timer_sync() for the timers so that we don't have any asynchronous references after the unregister. Signed-off-by: David S. Miller <davem@davemloft.net> --- drivers/net/hamradio/6pack.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c index 7c4a4151ef0f2..9f0b1c342b770 100644 --- a/drivers/net/hamradio/6pack.c +++ b/drivers/net/hamradio/6pack.c @@ -683,14 +683,14 @@ static void sixpack_close(struct tty_struct *tty) if (!atomic_dec_and_test(&sp->refcnt)) down(&sp->dead_sem); - unregister_netdev(sp->dev); - - del_timer(&sp->tx_t); - del_timer(&sp->resync_t); + del_timer_sync(&sp->tx_t); + del_timer_sync(&sp->resync_t); /* Free all 6pack frame buffers. */ kfree(sp->rbuff); kfree(sp->xbuff); + + unregister_netdev(sp->dev); } /* Perform I/O control on an active 6pack channel. */ -- GitLab