USB: opticon: fix DMA from stack

Make sure to allocate the control-message buffer dynamically as some
platforms cannot do DMA from stack.

Note that only the first byte of the old buffer was used.

Cc: <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index 41b1647306eb..459c28889fe4 100644
--- a/drivers/usb/serial/opticon.c
+++ b/drivers/usb/serial/opticon.c
@@ -155,7 +155,11 @@ static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
 {
         struct usb_serial *serial = port->serial;
         int retval;
-        u8 buffer[2];
+        u8 *buffer;
+
+        buffer = kzalloc(1, GFP_KERNEL);
+        if (!buffer)
+                return -ENOMEM;
 
         buffer[0] = val;
         /* Send the message to the vendor control endpoint
@@ -164,6 +168,7 @@ static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
                                 requesttype,
                                 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
                                 0, 0, buffer, 1, 0);
+        kfree(buffer);
 
         return retval;
 }