[B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix double call of dev_queue_xmit

From: Sven Eckelmann <sven(a)narfation.org> 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@davemlof… Fixes: c33705188c49 ("batman-adv: Treat NET_XMIT_CN as transmit successfully") Signed-off-by: Sven Eckelmann <sven(a)narfation.org> Signed-off-by: Simon Wunderlich <sw(a)simonwunderlich.de> --- net/batman-adv/send.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index d9b2889064a6..1489ec27daff 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; -- 2.11.0