From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (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 A4CFE30C16C for ; Sun, 24 May 2026 19:24:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.216.245.30 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779650675; cv=none; b=XKoxMRa1KrFgwxcJs3mKZfBOY7ZPoKIiV019K4wEyaa2dMJFIU43fkI5jUyB127hXeB9rekPaNFAnDAlRE+40yozEGfCVfHVqjzIj0iZ1uu8Y9bTruvKlsnbz19nTeWcfH4eDSKkr7QMYtiH4Y1WL+tNfEeNt8yfbajslwFVCpc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779650675; c=relaxed/simple; bh=dHf7NKSDF+0gStfWFSSFkPkHvRceO6sZguQ9gg9svqw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SfHS3U3M7xEv8nOnniALmPkCzgiyuHGSVJMhDlJ358E9+b8ho/2zTbvpr282OivdoIV43A+oEr7SICPFxzW54puoGfhV8lOwbw736RhCaxXxhcpXJzErP+HgzdbQ2wsMA2Xqulo5YD/9elvgkdM7DQmiAckkGqfdFKnwKWtxOFI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de; spf=pass smtp.mailfrom=strlen.de; arc=none smtp.client-ip=91.216.245.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=strlen.de Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003) id 1D12160425; Sun, 24 May 2026 21:24:31 +0200 (CEST) Date: Sun, 24 May 2026 21:24:30 +0200 From: Florian Westphal To: Fernando Fernandez Mancera Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, pablo@netfilter.org, phil@nwl.cc Subject: Re: [PATCH 0/3 nf-next] netfilter: synproxy: timestamp adjustment fixes Message-ID: References: <20260523194743.5888-2-fmancera@suse.de> <7dcb73cb-11ab-4c9d-89bd-7418bdc86fdb@suse.de> <3178bbf8-552a-45cf-819f-bf3ec2de41e0@suse.de> 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=us-ascii Content-Disposition: inline In-Reply-To: <3178bbf8-552a-45cf-819f-bf3ec2de41e0@suse.de> Fernando Fernandez Mancera wrote: > Hm. That might be an appealing argument for the dup timestamp option, if we > want to be more relaxed we can just adjust all timestamp options equally (we > need to assume that this is a corner case of course). > > But when failing skb_ensure_writable() or when encountering completely > malformed options I believe we should drop the packet. Not so sure. skb_ensure_writable() -> yes. But for malformed options? I think it should be done by policy. Not even conntrack drops such packets at the moment. Could you use NF_DROP_REASON() in next version? NF_DROP conceals the drop location which makes debugging harder. Thanks!