rtl8150: Use heap buffers for all register access

[ Upstream commit 7926aff5 ]

Allocating USB buffers on the stack is not portable, and no longer
works on x86_64 (with VMAP_STACK enabled as per default).

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/usb/rtl8150.c

@@ -155,16 +155,36 @@ static const char driver_name [] = "rtl8150";
 */
 static int get_registers(rtl8150_t * dev, u16 indx, u16 size, void *data)
 {
-	return usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
+	void *buf;
+	int ret;
+
+	buf = kmalloc(size, GFP_NOIO);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
 			      RTL8150_REQ_GET_REGS, RTL8150_REQT_READ,
-			       indx, 0, data, size, 500);
+			      indx, 0, buf, size, 500);
+	if (ret > 0 && ret <= size)
+		memcpy(data, buf, ret);
+	kfree(buf);
+	return ret;
 }
 
-static int set_registers(rtl8150_t * dev, u16 indx, u16 size, void *data)
+static int set_registers(rtl8150_t * dev, u16 indx, u16 size, const void *data)
 {
-	return usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
+	void *buf;
+	int ret;
+
+	buf = kmemdup(data, size, GFP_NOIO);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
 			      RTL8150_REQ_SET_REGS, RTL8150_REQT_WRITE,
-			       indx, 0, data, size, 500);
+			      indx, 0, buf, size, 500);
+	kfree(buf);
+	return ret;
 }
 
 static void async_set_reg_cb(struct urb *urb)