patch "staging: vt6656: use off stack for out buffer USB transfers." added to staging-testing

This is a note to let you know that I've just added the patch titled

staging: vt6656: use off stack for out buffer USB transfers.

to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-testing branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will be merged to the staging-next branch sometime soon, after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.

From: Malcolm Priestley <[email protected]>
Date: Sat, 22 Apr 2017 11:14:57 +0100
Subject: staging: vt6656: use off stack for out buffer USB transfers.

Since 4.9 mandated USB buffers be heap allocated this causes the driver to fail.

Since there is a wide range of buffer sizes use kmemdup to create allocated buffer.

---
 drivers/staging/vt6656/usbpipe.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

index 9ad8503d2589..ea5a7c65ad1b 100644
@@ -47,15 +47,25 @@ int vnt_control_out(struct vnt_private *priv, u8 request, u16 value,
 		     u16 index, u16 length, u8 *buffer)
 {
 	int status = 0;
+	u8 *usb_buffer;
 
 	if (test_bit(DEVICE_FLAGS_DISCONNECTED, &priv->flags))
 		return STATUS_FAILURE;
 
 	mutex_lock(&priv->usb_lock);
 
+	usb_buffer = kmemdup(buffer, length, GFP_KERNEL);
+	if (!usb_buffer) {
+		mutex_unlock(&priv->usb_lock);
+		return -ENOMEM;
+	}
+
 	status = usb_control_msg(priv->usb,
-		usb_sndctrlpipe(priv->usb, 0), request, 0x40, value,
-			index, buffer, length, USB_CTL_WAIT);
+				 usb_sndctrlpipe(priv->usb, 0),
+				 request, 0x40, value,
+				 index, usb_buffer, length, USB_CTL_WAIT);
+
+	kfree(usb_buffer);
 
 	mutex_unlock(&priv->usb_lock);
 

2.12.2