USB: cdc-acm: fix potential null-pointer dereference
Must check return value of tty_port_tty_get.
Cc: stable <stable@kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 00d809d..1756371 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -533,6 +533,8 @@
if (!ACM_READY(acm))
return;
tty = tty_port_tty_get(&acm->port);
+ if (!tty)
+ return;
tty_wakeup(tty);
tty_kref_put(tty);
}