diff options
| -rw-r--r-- | drivers/usb/class/cdc-acm.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index b632d4b53549..158f63121434 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -554,10 +554,18 @@ static void acm_port_down(struct acm *acm) static void acm_tty_hangup(struct tty_struct *tty) { - struct acm *acm = tty->driver_data; - tty_port_hangup(&acm->port); + struct acm *acm; + mutex_lock(&open_mutex); + acm = tty->driver_data; + + if (!acm) + goto out; + + tty_port_hangup(&acm->port); acm_port_down(acm); + +out: mutex_unlock(&open_mutex); } |