From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Sat, 11 Jul 2015 19:16:08 +0000 (+0200)
Subject: can: slcan: don't touch skb after netif_rx_ni()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a2e78cf7a3f562edca4230b188c8832b6214eccd;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

can: slcan: don't touch skb after netif_rx_ni()

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: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---

diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index a23a7af8eb9a..9a3f15cb7ef4 100644
--- a/drivers/net/can/slcan.c
+++ b/drivers/net/can/slcan.c
@@ -218,10 +218,10 @@ static void slc_bump(struct slcan *sl)
 
 	memcpy(skb_put(skb, sizeof(struct can_frame)),
 	       &cf, sizeof(struct can_frame));
-	netif_rx_ni(skb);
 
 	sl->dev->stats.rx_packets++;
 	sl->dev->stats.rx_bytes += cf.can_dlc;
+	netif_rx_ni(skb);
 }
 
 /* parse tty input stream */