From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: [PATCH 08/12] can: sja1000: don't touch skb after netif_rx() Date: Wed, 15 Jul 2015 09:09:45 +0200 Message-ID: <1436944189-26618-9-git-send-email-mkl@pengutronix.de> References: <1436944189-26618-1-git-send-email-mkl@pengutronix.de> Cc: davem@davemloft.net, linux-can@vger.kernel.org, kernel@pengutronix.de, Marc Kleine-Budde , Wolfgang Grandegger , Oliver Hartkopp To: netdev@vger.kernel.org Return-path: In-Reply-To: <1436944189-26618-1-git-send-email-mkl@pengutronix.de> Sender: linux-can-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 Cc: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- drivers/net/can/sja1000/sja1000.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index 32bd7f451aa4..7b92e911a616 100644 --- 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; } -- 2.1.4