The following commit has been merged in the master branch: commit 7c946062b3ae2b7f002383e5e402113e98ad3c77 Author: Sven Eckelmann sven@narfation.org Date: Sat Jan 28 10:12:39 2017 +0100

batman-adv: Fix double call of dev_queue_xmit

The net_xmit_eval has side effects because it is not making sure that e isn't evaluated twice.

#define net_xmit_eval(e) ((e) == NET_XMIT_CN ? 0 : (e))

The code requested by David Miller [1]

return net_xmit_eval(dev_queue_xmit(skb));

will get transformed into

return ((dev_queue_xmit(skb)) == NET_XMIT_CN ? 0 : (dev_queue_xmit(skb)))

dev_queue_xmit will therefore be tried again (with an already consumed skb) whenever the return code is not NET_XMIT_CN.

[1] https://lkml.kernel.org/r/20170125.225624.965229145391320056.davem@davemloft...

Fixes: c33705188c49 ("batman-adv: Treat NET_XMIT_CN as transmit successfully") Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index d9b2889..1489ec2 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -77,6 +77,7 @@ int batadv_send_skb_packet(struct sk_buff *skb, { struct batadv_priv *bat_priv; struct ethhdr *ethhdr; + int ret;

bat_priv = netdev_priv(hard_iface->soft_iface);

@@ -115,7 +116,8 @@ int batadv_send_skb_packet(struct sk_buff *skb, * congestion and traffic shaping, it drops and returns NET_XMIT_DROP * (which is > 0). This will not be treated as an error. */ - return net_xmit_eval(dev_queue_xmit(skb)); + ret = dev_queue_xmit(skb); + return net_xmit_eval(ret); send_skb_err: kfree_skb(skb); return NET_XMIT_DROP;