USB: usb_serial_resume bug fix

Avoid potential null pointer dereference.

Signed-off-by: Sarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 426afaa0d9b8..497e29a700ca 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -1123,7 +1123,9 @@ int usb_serial_resume(struct usb_interface *intf)
 {
         struct usb_serial *serial = usb_get_intfdata(intf);
 
-        return serial->type->resume(serial);
+        if (serial->type->resume)
+                return serial->type->resume(serial);
+        return 0;
 }
 EXPORT_SYMBOL(usb_serial_resume);