Commit 9c64863a authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Marc Kleine-Budde

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: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent ef1d2e28
...@@ -429,10 +429,10 @@ static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl) ...@@ -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_packets++;
stats->rx_bytes += frame->can_dlc; stats->rx_bytes += frame->can_dlc;
netif_receive_skb(skb);
return 0; return 0;
} }
...@@ -960,9 +960,9 @@ static int c_can_handle_state_change(struct net_device *dev, ...@@ -960,9 +960,9 @@ static int c_can_handle_state_change(struct net_device *dev,
break; break;
} }
netif_receive_skb(skb);
stats->rx_packets++; stats->rx_packets++;
stats->rx_bytes += cf->can_dlc; stats->rx_bytes += cf->can_dlc;
netif_receive_skb(skb);
return 1; return 1;
} }
...@@ -1033,10 +1033,9 @@ static int c_can_handle_bus_err(struct net_device *dev, ...@@ -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 */ /* set a `lec` value so that we can check for updates later */
priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED); priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
netif_receive_skb(skb);
stats->rx_packets++; stats->rx_packets++;
stats->rx_bytes += cf->can_dlc; stats->rx_bytes += cf->can_dlc;
netif_receive_skb(skb);
return 1; return 1;
} }
......
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