[PATCH 4.15 081/105] can: cc770: Fix use after free in cc770_tx_interrupt()

From: Greg Kroah-Hartman
Date: Tue Mar 27 2018 - 12:43:45 EST


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

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

From: Andri Yngvason <andri.yngvason@xxxxxxxxx>

commit 9ffd7503944ec7c0ef41c3245d1306c221aef2be upstream.

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

Signed-off-by: Andri Yngvason <andri.yngvason@xxxxxxxxx>
Fixes: 746201235b3f ("can: cc770: Fix queue stall & dropped RTR reply")
Cc: linux-stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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);