This is a note to let you know that I've just added the patch titled tty: n_gsm: fix packet re-transmission without open control channel to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tty-n_gsm-fix-packet-re-transmission-without-open-co.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0a6a0ed1d0ce49ae199b8a8b91d5ebd900a0f392 Author: Daniel Starke <daniel.starke@xxxxxxxxxxx> Date: Fri Jul 1 08:16:50 2022 +0200 tty: n_gsm: fix packet re-transmission without open control channel [ Upstream commit 4fae831b3a71fc5a44cc5c7d0b8c1267ee7659f5 ] In the current implementation control packets are re-transmitted even if the control channel closed down during T2. This is wrong. Check whether the control channel is open before re-transmitting any packets. Note that control channel open/close is handled by T1 and not T2 and remains unaffected by this. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220701061652.39604-7-daniel.starke@xxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 83ec596bba93..e95004217292 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1532,7 +1532,7 @@ static void gsm_control_retransmit(struct timer_list *t) spin_lock_irqsave(&gsm->control_lock, flags); ctrl = gsm->pending_cmd; if (ctrl) { - if (gsm->cretries == 0) { + if (gsm->cretries == 0 || !gsm->dlci[0] || gsm->dlci[0]->dead) { gsm->pending_cmd = NULL; ctrl->error = -ETIMEDOUT; ctrl->done = 1;