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>
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 8c725f4..6038761 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -429,10 +429,10 @@
}
}
- netif_receive_skb(skb);
-
stats->rx_packets++;
stats->rx_bytes += frame->can_dlc;
+
+ netif_receive_skb(skb);
return 0;
}
@@ -960,9 +960,9 @@
break;
}
- netif_receive_skb(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
+ netif_receive_skb(skb);
return 1;
}
@@ -1033,10 +1033,9 @@
/* 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;
}
