From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Sat, 11 Jul 2015 19:16:08 +0000 (+0200)
Subject: can: usb_8dev: don't touch skb after netif_rx()
X-Git-Tag: v4.9.8~3868^2~33^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9b721a4cefcbdedadbe72b5ec405046c139cf8ad;p=platform%2Fkernel%2Flinux-rpi3.git

can: usb_8dev: don't touch skb after 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.

Cc: Bernd Krumboeck <b.krumboeck@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---

diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
index dd52c7a..de95b1c 100644
--- a/drivers/net/can/usb/usb_8dev.c
+++ b/drivers/net/can/usb/usb_8dev.c
@@ -461,10 +461,9 @@ static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
 	priv->bec.txerr = txerr;
 	priv->bec.rxerr = rxerr;
 
-	netif_rx(skb);
-
 	stats->rx_packets++;
 	stats->rx_bytes += cf->can_dlc;
+	netif_rx(skb);
 }
 
 /* Read data and status frames */
@@ -494,10 +493,9 @@ static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 		else
 			memcpy(cf->data, msg->data, cf->can_dlc);
 
-		netif_rx(skb);
-
 		stats->rx_packets++;
 		stats->rx_bytes += cf->can_dlc;
+		netif_rx(skb);
 
 		can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 	} else {