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 B34D012B94 for ; Sat, 18 Apr 2026 07:35:22 +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=1776497725; cv=none; b=DPMrUzZeYuu7fYRcjf9+UNY9XS9Rq/ofnEeNoCsAPh2s7ZmDYYPnbbUT7IsHRKwqwV2xiDTXRsJLBvvQtdEjI7KsQvfK4G9jEoPZ4fIB6hg6Qap2UjrPXZs0/ISGHlL4AgHaqOEXnT2gjys8Ot1YMOWywVY92suksUUzuIiC4MY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776497725; c=relaxed/simple; bh=Cf/pJrTZLEiAV616Nmw9XUtngQdekDMLt/ow+U9z+VA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=K2V0OL0G8RPihtXhAF3HGy31BGOkwc7opqTQr8RIKdkTIb6SET0+/kDF3HLBXloWrdAep8AVsGyGuE7CUxfW+epg/ThHJgM4bBibe2Q/tciLuOPokUPmgpH+9q+mNLl5BKZoMuXOg1odrZFoYCCoSUYrad/ZNzRdg+l6TMxbzfg= 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=G/XkuYNg; 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="G/XkuYNg" Received: from netfilter.org (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with UTF8SMTPSA id B5A4760177; Sat, 18 Apr 2026 09:28:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1776497287; bh=2xmlsraU38wls5r3dWhGbOWtCifRuAxGsJm3ose5Zxo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=G/XkuYNgq7WlKQX2BDhNe2GD8TbKRV2Zo5KmGzIJKgvYqejQMBhPLBUKIm8YSyn7J 0excfr3bBOfMjfRowYeFN2pzqI9evzZGE5ygBoL2t55dk+6LjSmcdOXWPsvnWf3aNc OXrUK0BXPSpDTzpKlfC1sCOb/tjbvGYpy+nzzw+we7IrnZBne0yZkZvXCeCNERMTXs /kzr4dV7SGDH/Bz9V//5gomih+J1s0P+MpXGPZoeht3Ry4Qmts8lhLEzscoSzBEKE0 ot3vw1YEWiXs5thYC1fhFMkQ/jBTcsJKk/nXag/kBljjcI9qOkxmdPcC+1RDAxuDKG gOLHcYDtQN70w== Date: Sat, 18 Apr 2026 09:28:05 +0200 From: Pablo Neira Ayuso To: Florian Westphal Cc: netfilter-devel@vger.kernel.org Subject: Re: [PATCH nf] netfilter: arp_tables: fix IEEE1394 ARP payload mangling Message-ID: References: <20260417131910.17932-1-fw@strlen.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=utf-8 Content-Disposition: inline In-Reply-To: <20260417131910.17932-1-fw@strlen.de> Hi Florian, On Fri, Apr 17, 2026 at 03:19:05PM +0200, Florian Westphal wrote: > sashiko.dev noticed that similar bug pattern exists in arpt_mangle: > "IEEE1394 ARP payloads omit the target hardware address, advancing > arpptr by hln after the source IP address skips over the actual target > IP address." > > Apply similar fix: check dev->type. If we're asked to mangle what > doesn't exist, drop the packet. I included a fix for this in: https://patchwork.kernel.org/project/netdevbpf/patch/20260417091422.342615-1-pablo@netfilter.org/ I forgot to mangle the patch title though to: netfilter: arp_tables: fix IEEE1394 ARP payload parsing > Fixes: 6752c8db8e0c ("firewire net, ipv4 arp: Extend hardware address and remove driver-level packet inspection.") > Signed-off-by: Florian Westphal > --- > Collides with a inflight patch. Are you referring to the patch I made? > I'll rebase or discard depending on what netdev@ does. > > net/ipv4/netfilter/arpt_mangle.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/net/ipv4/netfilter/arpt_mangle.c b/net/ipv4/netfilter/arpt_mangle.c > index a4e07e5e9c11..5a3560e1b59b 100644 > --- a/net/ipv4/netfilter/arpt_mangle.c > +++ b/net/ipv4/netfilter/arpt_mangle.c > @@ -13,6 +13,7 @@ static unsigned int > target(struct sk_buff *skb, const struct xt_action_param *par) > { > const struct arpt_mangle *mangle = par->targinfo; > + bool has_tgt_devaddr = true; > const struct arphdr *arp; > unsigned char *arpptr; > int pln, hln; > @@ -39,13 +40,33 @@ target(struct sk_buff *skb, const struct xt_action_param *par) > memcpy(arpptr, &mangle->u_s.src_ip, pln); > } > arpptr += pln; > + > + if (IS_ENABLED(CONFIG_FIREWIRE_NET)) { > + const struct net_device *dev = skb->dev; > + > + if (!dev) { > + /* can't munge without arphrd type. */ > + if (mangle->flags & (ARPT_MANGLE_TDEV|ARPT_MANGLE_TIP)) > + return NF_DROP; > + return mangle->target; > + } > + > + if (dev->type == ARPHRD_IEEE1394) > + has_tgt_devaddr = false; > + } > + > if (mangle->flags & ARPT_MANGLE_TDEV) { > + if (!has_tgt_devaddr) > + return NF_DROP; > + > if (ARPT_DEV_ADDR_LEN_MAX < hln || > (arpptr + hln > skb_tail_pointer(skb))) > return NF_DROP; > memcpy(arpptr, mangle->tgt_devaddr, hln); > } > - arpptr += hln; > + if (has_tgt_devaddr) > + arpptr += hln; > + > if (mangle->flags & ARPT_MANGLE_TIP) { > if (ARPT_MANGLE_ADDR_LEN_MAX < pln || > (arpptr + pln > skb_tail_pointer(skb))) > -- > 2.52.0 > >