From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Subject: Re: ipv6: handle -EFAULT from skb_copy_bits
Date: Wed, 21 Dec 2016 13:41:13 +0100
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Cc: David Miller <davem@davemloft.net>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>
To: Cong Wang <xiyou.wangcong@gmail.com>,
        Dave Jones <davej@codemonkey.org.uk>
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On Wed, 2016-12-21 at 13:27 +0100, Hannes Frederic Sowa wrote: 
> @@ -555,8 +566,8 @@ static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
>                 goto out;
>  
>         offset = rp->offset;
> -       total_len = inet_sk(sk)->cork.base.length;
> -       if (offset >= total_len - 1) {
> +       transport_len = raw6_corked_transport_len(sk);
> +       if (offset >= transport_len - 1) {
>                 err = -EINVAL;
>                 ip6_flush_pending_frames(sk);
>                 goto out;
> @@ -598,7 +609,7 @@ static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
>                 tmp_csum = csum_sub(tmp_csum, csum_unfold(csum));
>  
>         csum = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
> -                              total_len, fl6->flowi6_proto, tmp_csum);
> +                              transport_len, fl6->flowi6_proto, tmp_csum);
>  
> 

Ops, here we need actually the total_len plus the opt->opt_nflen to
always calculate the correct checksum.