From: Eric Dumazet <eric.duma...@gmail.com>
Date: Thu, 02 Nov 2017 12:30:25 -0700
> From: Eric Dumazet <eduma...@google.com>
>
> Christoph Paasch sent a patch to address the following issue :
>
> tcp_make_synack() is leaving some TCP private info in skb->cb[],
> then send the packet by other means than tcp_transmit_skb()
>
> tcp_transmit_skb() makes sure to clear skb->cb[] to not confuse
> IPv4/IPV6 stacks, but we have no such cleanup for SYNACK.
>
> tcp_make_synack() should not use tcp_init_nondata_skb() :
>
> tcp_init_nondata_skb() really should be limited to skbs put in write/rtx
> queues (the ones that are only sent via tcp_transmit_skb())
>
> This patch fixes the issue and should even save few cpu cycles ;)
>
> Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line
> misses")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Reported-by: Christoph Paasch <cpaa...@apple.com>
Applied and queued up for -stable.
