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 E539F4219FF; Wed, 1 Jul 2026 11:01:59 +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=1782903721; cv=none; b=p3KCgX7uhSU5+FSLDmO+KT/ewXhK/yJY8qW3w7eepvoKTcX0EIhhN0d/5EkPXSDQORpiqwWhExMZKIbiZQX1/76FRYbhsMxmaUuu1ompeOsqP2jdGVZ2rz4SZ8KDtKb0G9mMGSKA7qPMIifrUoHliHx5YjC23M7ypf/yFXAgdEA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782903721; c=relaxed/simple; bh=XaYWtMGNgt5FOX7HON74P5yka1JQED5HVnel31HcEoI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Da1VhmmHGg/lHK5MEmyPTTkrwJI3f4XJSy9U+LYD/5FlUB38xeFFqx8FlBho83TeE44WGC53EBtqc2eeT957Bb2RdMKUpZg4gjhthxJKpLsi4457oXNUq/1RrRZWCdWqtfDLTDsi91qfAXG3Ql1IDmttfaSmDW7ZJmQ3JM6uWMY= 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=o8lzDtNE; 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="o8lzDtNE" Received: from netfilter.org (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with UTF8SMTPSA id 3C62760588; Wed, 1 Jul 2026 13:01:57 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1782903717; bh=QxPuanMrXViRFbZ/7f1IxjQONUCuWhm+IzkoyoL4DB0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=o8lzDtNER8nYIuqXeHHb6FJZAoZ1lRZirWcx1tp/q8AMbha2SITBChlZS4ziyGKGp aqyqES01Q5lveMQMsxf4YHS3Jw4XdlktfQ3j17pwDqM2nPk7cr5bvecsQsd3NNOsqP iz8d1J+IPCrfZpe5tOdE9UDvq0MwE6pXnZWeEIWmT57Os/m3p9ac0rGqZakxpfhLys tho6eubVUprj5Xy5SGQ/HzT6bZuzLvwFzkPwq03TYb8B3yu506Y8uyyCxQday+PDO1 q7E2kxxxLQEBAwDXnmMTy4mGOit3bbXxPqiKSaCE6aX/aH5VkbzxZ5WHl+yyBp/BBy F7vCwrNfn/QlQ== Date: Wed, 1 Jul 2026 13:01:54 +0200 From: Pablo Neira Ayuso To: Florian Westphal Cc: netdev@vger.kernel.org, Paolo Abeni , "David S. Miller" , Eric Dumazet , Jakub Kicinski , netfilter-devel@vger.kernel.org Subject: Re: [PATCH net 4/9] netfilter: nf_conntrack_sip: validate skb_dst() before accessing it Message-ID: References: <20260630045243.2657-1-fw@strlen.de> <20260630045243.2657-5-fw@strlen.de> Precedence: bulk X-Mailing-List: netdev@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, Jul 01, 2026 at 08:36:11AM +0200, Florian Westphal wrote: > Florian Westphal wrote: > > From: Pablo Neira Ayuso > > > > tc ingress and openvswitch do not guarantee routing information to be > > available. These subsystems use the conntrack helper infrastructure, and > > the SIP helper relies on the skb_dst() to be present if > > sip_external_media is set to 1 (which is disabled by default as a module > > parameter). > > The sashiko drive-by appears real, I submitted a patch for it. > Its not a regression added by this patch but a unrelated issue. > > https://patchwork.ozlabs.org/project/netfilter-devel/patch/20260701062922.9660-1-fw@strlen.de/ Is skb_ensure_writable() bogus here? As you said, skb is already linearized. As for clones, they should only happen in br_netfilter? In such case, it should be br_netfilter that should be audited not to pass cloned skbuffs before calling the inet hooks.