acm: Fix oops when closing ACM tty device right after open has failed.

[safe/jmp/linux-2.6] / drivers / usb / class / cdc-acm.c

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 02eb60b..3f10459 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -677,7 +677,7 @@ 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 (tty_port_close_start(&acm->port, tty, filp) == 0)
+       if (!acm || tty_port_close_start(&acm->port, tty, filp) == 0)
                return;
        acm_port_down(acm, 0);
        tty_port_close_end(&acm->port, tty);