From e320e8f63f3475a392c29b008323979f7abca6ee 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 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: 99551fa31543 ("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 6b953dfbb1557..1430d7f83bd2e 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2152,6 +2152,7 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc) 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); -- 2.39.5