From 5a503b98d09c3f96cc6644d639b0c012745b6500 Mon Sep 17 00:00:00 2001 From: Daniel Starke Date: Thu, 14 Apr 2022 02:42:15 -0700 Subject: [PATCH] tty: n_gsm: fix missing explicit ldisc flush commit 17eac652028501df7ea296b1d9b9c134db262b7d upstream. In gsm_cleanup_mux() the muxer is closed down and all queues are removed. However, removing the queues is done without explicit control of the underlying buffers. Flush those before freeing up our queues to ensure that all outgoing queues are cleared consistently. Otherwise, a new mux connection establishment attempt may time out while the underlying tty is still busy sending out the remaining data from the previous connection. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke Link: https://lore.kernel.org/r/20220414094225.4527-10-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_gsm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 48400408c5c9..f02fe9a6593a 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2101,6 +2101,7 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm) gsm_dlci_release(gsm->dlci[i]); mutex_unlock(&gsm->mutex); /* Now wipe the queues */ + tty_ldisc_flush(gsm->tty); list_for_each_entry_safe(txq, ntxq, &gsm->tx_list, list) kfree(txq); INIT_LIST_HEAD(&gsm->tx_list); -- 2.34.1