[PATCH 4.9 47/67] can: cc770: Fix use after free in cc770_tx_interrupt()

[Greg Kroah-Hartman]

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

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

From: Andri Yngvason <andri.yngva...@marel.com>

commit 9ffd7503944ec7c0ef41c3245d1306c221aef2be upstream.

This fixes use after free introduced by the last cc770 patch.

Signed-off-by: Andri Yngvason <andri.yngva...@marel.com>
Fixes: 746201235b3f ("can: cc770: Fix queue stall & dropped RTR reply")
Cc: linux-stable <sta...@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <m...@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/net/can/cc770/cc770.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/net/can/cc770/cc770.c
+++ b/drivers/net/can/cc770/cc770.c
@@ -706,13 +706,12 @@ static void cc770_tx_interrupt(struct ne
                return;
        }
 
-       can_put_echo_skb(priv->tx_skb, dev, 0);
-       can_get_echo_skb(dev, 0);
-
        cf = (struct can_frame *)priv->tx_skb->data;
        stats->tx_bytes += cf->can_dlc;
        stats->tx_packets++;
 
+       can_put_echo_skb(priv->tx_skb, dev, 0);
+       can_get_echo_skb(dev, 0);
        priv->tx_skb = NULL;
 
        netif_wake_queue(dev);