media: dvb: i2c transfers over usb cannot be done from stack

BugLink: http://bugs.launchpad.net/bugs/1745047

commit 6d33377f upstream.
Signed-off-by: Laurent Caumont <lcaumont2@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/media/usb/dvb-usb/dibusb-common.c

@@ -179,8 +179,20 @@ EXPORT_SYMBOL(dibusb_i2c_algo);
 
 int dibusb_read_eeprom_byte(struct dvb_usb_device *d, u8 offs, u8 *val)
 {
-	u8 wbuf[1] = { offs };
-	return dibusb_i2c_msg(d, 0x50, wbuf, 1, val, 1);
+	u8 *buf;
+	int rc;
+
+	buf = kmalloc(2, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	buf[0] = offs;
+
+	rc = dibusb_i2c_msg(d, 0x50, &buf[0], 1, &buf[1], 1);
+	*val = buf[1];
+	kfree(buf);
+
+	return rc;
 }
 EXPORT_SYMBOL(dibusb_read_eeprom_byte);