From: Xie He <xie.he.0...@gmail.com> Date: Sat, 26 Sep 2020 13:56:10 -0700
> @@ -265,7 +269,9 @@ static void x25_asy_write_wakeup(struct tty_struct *tty) > * transmission of another packet */ > sl->dev->stats.tx_packets++; > clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); > - x25_asy_unlock(sl); > + /* FIXME: The netif may go down after netif_running returns */ > + if (netif_running(sl->dev)) > + x25_asy_unlock(sl); > return; It could also go back down and also back up again after you do this test. Maybe even 10 or 100 times over. You can't just leave things so incredibly racy like this, please apply proper synchronization between netdev state changes and this TTY code. Thank you.