Re: kernel v4.8: iptables logs are truncated with the 4.8 kernel?

[Chris Caputo]

On Tue, 11 Oct 2016, Liping Zhang wrote:
> Yes, thanks for clarifying this. There's a bug in kernel, can you try
> this patch:
> 
> diff --git a/net/netfilter/xt_NFLOG.c b/net/netfilter/xt_NFLOG.c
> index 018eed7..8c069b4 100644
> --- a/net/netfilter/xt_NFLOG.c
> +++ b/net/netfilter/xt_NFLOG.c
> @@ -32,6 +32,7 @@ nflog_tg(struct sk_buff *skb, const struct
> xt_action_param *par)
>         li.u.ulog.copy_len   = info->len;
>         li.u.ulog.group      = info->group;
>         li.u.ulog.qthreshold = info->threshold;
> +       li.u.ulog.flags      = 0;
> 
>         if (info->flags & XT_NFLOG_F_COPY_LEN)
>                 li.u.ulog.flags |= NF_LOG_F_COPY_LEN;

I have tested the above patch with 4.8.1, with and without nflog-size 
defined in an iptables configuration, and it works well.

The ulogd-2.0.5 segfaults no longer happen when nflog-size is not present 
in a target.

I recommend this fix.

Thanks,
Chris