can: dev: can_restart: fix use after free bug

After calling netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is accessed
after the netif_rx_ni() in:
      stats->rx_bytes += cf->len;

Reordering the lines solves the issue.

Fixes: 39549eef35 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/r/20210120114137.200019-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Vincent Mailhol 2021-01-20 20:41:35 +09:00 committed by Marc Kleine-Budde
parent 9c30ae8398
commit 03f16c5075

View File

@ -592,11 +592,11 @@ static void can_restart(struct net_device *dev)
cf->can_id |= CAN_ERR_RESTARTED;
netif_rx_ni(skb);
stats->rx_packets++;
stats->rx_bytes += cf->len;
netif_rx_ni(skb);
restart:
netdev_dbg(dev, "restarted\n");
priv->can_stats.restarts++;