[ 081/105] USB: opticon: fix DMA from stack

[Ben Hutchings]

3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <jhovold@xxxxxxxxx>

commit ea0dbebffe118724cd4df7d9b071ea8ee48d48f0 upstream.

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.

Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/usb/serial/opticon.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index 41b1647..459c288 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;
 }


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