can: c_can: Do not access skb after net_receive_skb()

There is no guarantee that the skb is in the same state after calling
net_receive_skb(). 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.

The whole can subsystem is full of this. Copy and paste ....

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Thomas Gleixner 2014-04-11 08:13:12 +00:00 committed by Marc Kleine-Budde
parent ef1d2e286a
commit 9c64863a49

View File

@ -429,10 +429,10 @@ static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl)
}
}
netif_receive_skb(skb);
stats->rx_packets++;
stats->rx_bytes += frame->can_dlc;
netif_receive_skb(skb);
return 0;
}
@ -960,9 +960,9 @@ static int c_can_handle_state_change(struct net_device *dev,
break;
}
netif_receive_skb(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_receive_skb(skb);
return 1;
}
@ -1033,10 +1033,9 @@ static int c_can_handle_bus_err(struct net_device *dev,
/* set a `lec` value so that we can check for updates later */
priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
netif_receive_skb(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_receive_skb(skb);
return 1;
}