1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index b72fa49eb257..e4eca7810bcf 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -686,15 +686,21 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 
         /* Perform the closing process and see if we need to do the hardware
            shutdown */
-        if (!acm || tty_port_close_start(&acm->port, tty, filp) == 0)
+        if (!acm)
+                return;
+        if (tty_port_close_start(&acm->port, tty, filp) == 0) {
+                mutex_lock(&open_mutex);
+                if (!acm->dev) {
+                        tty_port_tty_set(&acm->port, NULL);
+                        acm_tty_unregister(acm);
+                        tty->driver_data = NULL;
+                }
+                mutex_unlock(&open_mutex);
                 return;
+        }
         acm_port_down(acm, 0);
         tty_port_close_end(&acm->port, tty);
-        mutex_lock(&open_mutex);
         tty_port_tty_set(&acm->port, NULL);
-        if (!acm->dev)
-                acm_tty_unregister(acm);
-        mutex_unlock(&open_mutex);
 }
 
 static int acm_tty_write(struct tty_struct *tty,