platform/x86: intel_mid_powerbtn: Take a copy of ddata

commit 5e0c94d3 upstream.

The driver gets driver_data from memory that is marked as const (which
is probably put to read-only memory) and it then modifies it. This
likely causes some sort of fault to happen.

Fix this by taking a copy of the structure.

Fixes: c94a8ff1 ("platform/x86: intel_mid_powerbtn: make mid_pb_ddata const")
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/platform/x86/intel_mid_powerbtn.c

@@ -158,9 +158,10 @@ static int mid_pb_probe(struct platform_device *pdev)
 
 	input_set_capability(input, EV_KEY, KEY_POWER);
 
-	ddata = (struct mid_pb_ddata *)id->driver_data;
+	ddata = devm_kmemdup(&pdev->dev, (void *)id->driver_data,
+			     sizeof(*ddata), GFP_KERNEL);
 	if (!ddata)
-		return -ENODATA;
+		return -ENOMEM;
 
 	ddata->dev = &pdev->dev;
 	ddata->irq = irq;