Re: [PATCH net-next v3] net: sched: fix skb leak in dev_requeue_skb()

[David Miller <davem@davemloft.net>]

From: Wei Yongjun <weiyongjun1@huawei.com>
Date: Wed, 27 Dec 2017 17:05:52 +0800

> When dev_requeue_skb() is called with bluked skb list, only the
                                        ^^^^^^

"bulked"

> first skb of the list will be requeued to qdisc layer, and leak
> the others without free them.
> 
> TCP is broken due to skb leak since no free skb will be considered
> as still in the host queue and never be retransmitted. This happend
> when dev_requeue_skb() called from qdisc_restart().
>   qdisc_restart
>   |-- dequeue_skb
>   |-- sch_direct_xmit()
>       |-- dev_requeue_skb() <-- skb may bluked
> 
> Fix dev_requeue_skb() to requeue the full bluked list. Also change
> to use __skb_queue_tail() in __dev_requeue_skb() to avoid skb out
> of order.
> 
> Fixes: a53851e2c321 ("net: sched: explicit locking in gso_cpu fallback")
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> ---
> v2 -> v3: move lock out of while loop

Applied, thank you.