can: sja1000: don't touch skb after netif_rx()

There is no guarantee that the skb is in the same state after calling
net_receive_skb() or netif_rx(). It might be freed or reused. Not really
harmful as its a read access, except you turn on the proper debugging options
which catch a use after free.

Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index 32bd7f451aa42b53f0a479af667861db6693d619..7b92e911a6168badb3e30f8fc55b2e6fdd0f61dc 100644 (file)
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -377,10 +377,9 @@ static void sja1000_rx(struct net_device *dev)
        /* release receive buffer */
        sja1000_write_cmdreg(priv, CMD_RRB);
 
-       netif_rx(skb);
-
        stats->rx_packets++;
        stats->rx_bytes += cf->can_dlc;
+       netif_rx(skb);
 
        can_led_event(dev, CAN_LED_EVENT_RX);
 }
@@ -484,10 +483,9 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
                        can_bus_off(dev);
        }
 
-       netif_rx(skb);
-
        stats->rx_packets++;
        stats->rx_bytes += cf->can_dlc;
+       netif_rx(skb);
 
        return 0;
 }