can: at91_can: don't touch skb after netif_receive_skb()/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.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index f4e40aa..945c095 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -577,10 +577,10 @@
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
- netif_receive_skb(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
+ netif_receive_skb(skb);
}
/**
@@ -642,10 +642,10 @@
}
at91_read_mb(dev, mb, cf);
- netif_receive_skb(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
+ netif_receive_skb(skb);
can_led_event(dev, CAN_LED_EVENT_RX);
}
@@ -802,10 +802,10 @@
return 0;
at91_poll_err_frame(dev, cf, reg_sr);
- netif_receive_skb(skb);
dev->stats.rx_packets++;
dev->stats.rx_bytes += cf->can_dlc;
+ netif_receive_skb(skb);
return 1;
}
@@ -1067,10 +1067,10 @@
return;
at91_irq_err_state(dev, cf, new_state);
- netif_rx(skb);
dev->stats.rx_packets++;
dev->stats.rx_bytes += cf->can_dlc;
+ netif_rx(skb);
priv->can.state = new_state;
}