[PATCH 4.9 038/148] media: dvb: i2c transfers over usb cannot be done from stack

[Greg Kroah-Hartman]

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

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

From: Laurent Caumont <lcaumont2@xxxxxxxxx>

commit 6d33377f2abbf9f0e561b116dd468d1c3ff36a6a upstream.

Signed-off-by: Laurent Caumont <lcaumont2@xxxxxxxxx>
Signed-off-by: Sean Young <sean@xxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/media/usb/dvb-usb/dibusb-common.c |   16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

--- a/drivers/media/usb/dvb-usb/dibusb-common.c
+++ b/drivers/media/usb/dvb-usb/dibusb-common.c
@@ -223,8 +223,20 @@ 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);