From: Daniel Starke daniel.starke@siemens.com
commit deefc58bafb4841df7f0a0d85d89a1c819db9743 upstream.
The current DLCI release order starts with the control channel followed by the user channels. Reverse this order to keep the control channel open until all user channels have been released.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke daniel.starke@siemens.com Link: https://lore.kernel.org/r/20220414094225.4527-9-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/n_gsm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2081,8 +2081,8 @@ static void gsm_cleanup_mux(struct gsm_m /* Finish outstanding timers, making sure they are done */ del_timer_sync(&gsm->t2_timer);
- /* Free up any link layer users */ - for (i = 0; i < NUM_DLCI; i++) + /* Free up any link layer users and finally the control channel */ + for (i = NUM_DLCI - 1; i >= 0; i--) if (gsm->dlci[i]) gsm_dlci_release(gsm->dlci[i]); mutex_unlock(&gsm->mutex);