USB: ftdi_sio: fix problem when the manufacture is a NULL string

On some misconfigured ftdi_sio devices, if the manufacturer string is
NULL, the kernel will oops when the device is plugged in.  This patch
fixes the problem.

Reported-by: Wojciech M Zabolotny <W.Zabolotny@elka.pw.edu.pl>
Tested-by: Wojciech M Zabolotny <W.Zabolotny@elka.pw.edu.pl>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index feafa85dd07e..989262606684 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1769,7 +1769,8 @@ static int ftdi_8u2232c_probe(struct usb_serial *serial)
 
         dbg("%s", __func__);
 
-        if (strcmp(udev->manufacturer, "CALAO Systems") == 0)
+        if ((udev->manufacturer) &&
+            (strcmp(udev->manufacturer, "CALAO Systems") == 0))
                 return ftdi_jtag_probe(serial);
 
         return 0;