From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9AAE9391E7C for ; Wed, 13 May 2026 15:52:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.190.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778687550; cv=none; b=TzHlI4jXJcMGkYcyaWqaxT84s3OmLyGMT3wS5stlv3q4npeo5RZYwUhDlnxe7PHVZucnC5S1jBgQ1fy7DN8/4BR+asaRVVb2i/K/xk53K1B/bmXYHp/L6wGeZdPjRklx9dav9Cm3yzcw1MnFGy4mrESLEtZ/7IcwV29npFJ/njQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778687550; c=relaxed/simple; bh=OXRVSBntJaY4dNcBDStfk+26qUYAt9IpzLS01HrBe3M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jvsHf7tEvuKPIgX49UUuyOg6WDwlQ/ry9b0cuoz0wtDnCEmWe4HXhdl3iYizJTpW6TzSFi2KodtIFhZHYRA74HmAnsdwo9FkyBplg7571hLJMZP5KBy++Mw5AiUudlHFBlRxEOFK2sLiq8mdfnt6ZFUvhHwQbz9EeoafDj00ehw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b=iqWnmOyU; arc=none smtp.client-ip=217.70.190.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b="iqWnmOyU" Received: from netfilter.org (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with UTF8SMTPSA id D0B8C601B0; Wed, 13 May 2026 17:52:26 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1778687546; bh=Qoy5zlYo7xePVugMRKri7PL+vvuS3HtkruiXkfIUOvA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=iqWnmOyUsyqyIsliv1Nea3hbuASS8UJBr9wAZuUxzu8KKD3vrF4EnNJU0qfDKl7fS EIRIwb2ASqgeSo+2BXFPfNRG9wZm8K+sdGOQqN7+OJBNsFdVqGRFeOvn0wsWhnHqdf +P+oB10Oh2G8Ky5D7ucFhIYC37QXi+da+c76toY8PdBPZfTzwaUgD3oG+INK2wzt+e lC5eDLyUBVdfSsyJVn30QWlZ3HSk6u3lAqwrH3jTzmfPuq4irbaK3pjEoTSBEcWZHF Iu9PFX97+vca/SkQai3lQ/7CQSwCp1fcbAwQJGtVHVuF/TCPBbGm0bqycerMDglYs6 fSXY1NmNHt/iA== Date: Wed, 13 May 2026 17:52:24 +0200 From: Pablo Neira Ayuso To: Florian Westphal Cc: netfilter-devel@vger.kernel.org Subject: Re: [PATCH nf] netfilter: conntrack: add dead flag to helpers Message-ID: References: <20260512205823.803476-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Wed, May 13, 2026 at 05:38:43PM +0200, Pablo Neira Ayuso wrote: > On Wed, May 13, 2026 at 05:29:27PM +0200, Pablo Neira Ayuso wrote: > > On Wed, May 13, 2026 at 12:05:02PM +0200, Florian Westphal wrote: [...] > > > 3. synchronize_rcu() -> all skbs that had this helper have > > > left RCU protection > > > 4. nf_ct_expect_iterate_destroy() removes all not-yet-found > > > exp entries from table > > > 5. nf_ct_iterate_destroy() -> clear exp from nf_conn's that are > > > *in conntrack table* > > > > > > That still means we could have a NEW conntrack queued via nfqueue. > > > I think we also need to toss nfqueued packets after step 3) and > > > need to refuse queueing to userspace if the flag is set (-> drop). > > > > Those conntrack entries would now have help->helper == NULL because of > > the unhelp call. > > Oh, wait, _NEW_ conntracks are unreachable, so yes, that can happen. > > Tossing nfqueued packets here is convenient when helper goes away. Hm, but nf_ct_iterate_destroy() already deals with unconfirmed conntrack.