From: Fedor Pchelkin pchelkin@ispras.ru
commit c9ab053e56ce13a949977398c8edc12e6c02fc95 upstream.
A kick_timer timer_list is replaced with kick_timeout delayed_work to be able to synchronize with mutexes as a prerequisite for the introduction of tx_mutex.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: c568f7086c6e ("tty: n_gsm: fix missing timer to handle stalled links") Cc: stable stable@kernel.org Reviewed-by: Jiri Slaby jirislaby@kernel.org Suggested-by: Hillf Danton hdanton@sina.com Signed-off-by: Fedor Pchelkin pchelkin@ispras.ru Signed-off-by: Alexey Khoroshilov khoroshilov@ispras.ru Link: https://lore.kernel.org/r/20220829131640.69254-2-pchelkin@ispras.ru Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/n_gsm.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index d6598ca3640f..e23225aff5d9 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -256,7 +256,7 @@ struct gsm_mux { struct list_head tx_data_list; /* Pending data packets */
/* Control messages */ - struct timer_list kick_timer; /* Kick TX queuing on timeout */ + struct delayed_work kick_timeout; /* Kick TX queuing on timeout */ struct timer_list t2_timer; /* Retransmit timer for commands */ int cretries; /* Command retry counter */ struct gsm_control *pending_cmd;/* Our current pending command */ @@ -1009,7 +1009,7 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) gsm->tx_bytes += msg->len;
gsmld_write_trigger(gsm); - mod_timer(&gsm->kick_timer, jiffies + 10 * gsm->t1 * HZ / 100); + schedule_delayed_work(&gsm->kick_timeout, 10 * gsm->t1 * HZ / 100); }
/** @@ -1984,16 +1984,16 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len) }
/** - * gsm_kick_timer - transmit if possible - * @t: timer contained in our gsm object + * gsm_kick_timeout - transmit if possible + * @work: work contained in our gsm object * * Transmit data from DLCIs if the queue is empty. We can't rely on * a tty wakeup except when we filled the pipe so we need to fire off * new data ourselves in other cases. */ -static void gsm_kick_timer(struct timer_list *t) +static void gsm_kick_timeout(struct work_struct *work) { - struct gsm_mux *gsm = from_timer(gsm, t, kick_timer); + struct gsm_mux *gsm = container_of(work, struct gsm_mux, kick_timeout.work); unsigned long flags; int sent = 0;
@@ -2458,7 +2458,7 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc) }
/* Finish outstanding timers, making sure they are done */ - del_timer_sync(&gsm->kick_timer); + cancel_delayed_work_sync(&gsm->kick_timeout); del_timer_sync(&gsm->t2_timer);
/* Finish writing to ldisc */ @@ -2605,7 +2605,7 @@ static struct gsm_mux *gsm_alloc_mux(void) kref_init(&gsm->ref); INIT_LIST_HEAD(&gsm->tx_ctrl_list); INIT_LIST_HEAD(&gsm->tx_data_list); - timer_setup(&gsm->kick_timer, gsm_kick_timer, 0); + INIT_DELAYED_WORK(&gsm->kick_timeout, gsm_kick_timeout); timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0); INIT_WORK(&gsm->tx_work, gsmld_write_task); init_waitqueue_head(&gsm->event);