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Date: Wed, 13 May 2026 14:45:52 +0200
From: Florian Westphal <fw@strlen.de>
To: Fernando Fernandez Mancera <fmancera@suse.de>
Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, phil@nwl.cc,
	pablo@netfilter.org,
	Alejandro Olivan Alvarez <alejandro.olivan.alvarez@gmail.com>
Subject: Re: [PATCH nf] netfilter: nf_conncount: prevent connlimit drops for
 early confirmed ct
Message-ID: <agRygM7hHtKs8jQB@strlen.de>
References: <20260513121547.6434-1-fmancera@suse.de>
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Fernando Fernandez Mancera <fmancera@suse.de> wrote:
>  	if (ct && nf_ct_is_confirmed(ct)) {
> -		/* local connections are confirmed in postrouting so confirmation
> -		 * might have happened before hitting connlimit
> -		 */
> -		if (skb->skb_iif != LOOPBACK_IFINDEX) {
> +		if (test_bit(IPS_ASSURED_BIT, &ct->status) || ctinfo == IP_CT_ESTABLISHED) {
>  			err = -EEXIST;
>  			goto out_put;
>  		}

IIRC IP_CT_ESTABLISHED requires we can observe traffic in both
directions.  I'm not sure it was a good idea to allow this new
usage case added in 69894e5b4c5e ("netfilter: nft_connlimit: update the count if add was skipped"),
but I don't think we can revert it either :-(

No idea how to fix this mess.