From: Willem de Bruijn <willemdebruijn.ker...@gmail.com>
Date: Wed, 1 Jul 2020 16:00:06 -0400
> From: Willem de Bruijn <will...@google.com>
>
> When no full socket is available, skbs are sent over a per-netns
> control socket. Its sk_mark is temporarily adjusted to match that
> of the real (request or timewait) socket or to reflect an incoming
> skb, so that the outgoing skb inherits this in __ip_make_skb.
>
> Introduction of the socket cookie mark field broke this. Now the
> skb is set through the cookie and cork:
>
> <caller> # init sockc.mark from sk_mark or cmsg
> ip_append_data
> ip_setup_cork # convert sockc.mark to cork mark
> ip_push_pending_frames
> ip_finish_skb
> __ip_make_skb # set skb->mark to cork mark
>
> But I missed these special control sockets. Update all callers of
> __ip(6)_make_skb that were originally missed.
>
> For IPv6, the same two icmp(v6) paths are affected. The third
> case is not, as commit 92e55f412cff ("tcp: don't annotate
> mark on control socket from tcp_v6_send_response()") replaced
> the ctl_sk->sk_mark with passing the mark field directly as a
> function argument. That commit predates the commit that
> introduced the bug.
>
> Fixes: c6af0c227a22 ("ip: support SO_MARK cmsg")
> Signed-off-by: Willem de Bruijn <will...@google.com>
> Reported-by: Martin KaFai Lau <ka...@fb.com>
Applied and queued up for -stable, thanks.
