[PATCH 4.9 121/177] video: fbdev: udlfb: Fix buffer on stack

[Greg Kroah-Hartman]

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

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

From: Maksim Salau <maksim.salau@xxxxxxxxx>


[ Upstream commit 45f580c42e5c125d55dbd8099750a1998de3d917 ]

Allocate buffers on HEAP instead of STACK for local array
that is to be sent using usb_control_msg().

Signed-off-by: Maksim Salau <maksim.salau@xxxxxxxxx>
Cc: Bernie Thompson <bernie@xxxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/video/fbdev/udlfb.c |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

--- a/drivers/video/fbdev/udlfb.c
+++ b/drivers/video/fbdev/udlfb.c
@@ -1487,15 +1487,25 @@ static struct device_attribute fb_device
 static int dlfb_select_std_channel(struct dlfb_data *dev)
 {
 	int ret;
-	u8 set_def_chn[] = {	   0x57, 0xCD, 0xDC, 0xA7,
+	void *buf;
+	static const u8 set_def_chn[] = {
+				0x57, 0xCD, 0xDC, 0xA7,
 				0x1C, 0x88, 0x5E, 0x15,
 				0x60, 0xFE, 0xC6, 0x97,
 				0x16, 0x3D, 0x47, 0xF2  };
 
+	buf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
+
+	if (!buf)
+		return -ENOMEM;
+
 	ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
 			NR_USB_REQUEST_CHANNEL,
 			(USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
-			set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
+			buf, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
+
+	kfree(buf);
+
 	return ret;
 }