USB: cdc-acm: fix potential null-pointer dereference

commit 15e5bee33ffc11d0e5c6f819a65e7881c5c407be upstream.

Must check return value of tty_port_tty_get.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 073a9ef9fe605059a5d6b846a1a9b7fafec6cfe8..af5ed89ca98cc97e8926b5bfea6a94fd3ebbb05f 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -534,6 +534,8 @@ static void acm_softint(struct work_struct *work)
        if (!ACM_READY(acm))
                return;
        tty = tty_port_tty_get(&acm->port);
+       if (!tty)
+               return;
        tty_wakeup(tty);
        tty_kref_put(tty);
 }