From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.70.190.124 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794539581; b=CXWp/CUvWkWSSvxVGOzehKB8d5lKnNX+oOPQ8tFRmgJn3P49eXitPUAdkRHtcE1Y6JFe akcEexXD9olIuSicbzJIORgiutGDGc9fzcvZGnYGKV7ypXVnoNXRn5RU46KQ5Rr9iM6wS OlQHiGaW+pD/ZkaWvrc3nnwv2RwWUELga5Y+Lm1XBQMdv5kesv9EhlC5J9DJEUaUHcqd7 cKgIPJiEjgtbj5D28vMP8RNQ1HguvAz1/45CqtcERH+TujHQE/IHeFokAW6B3ZLyYJuPf q7U42P3MUet/AXmgmXq2opcrSB3grxDzJcDAM8IlggZdS0ZORTOr8F1sxRW7l+AvzQg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794539581; h=DMARC-Filter:DKIM-Signature:Received:From:To:Cc:Subject:Date: Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-Spam-Status:X-Spam-Checker-Version; bh=VwXdHxOfjvzzynD1vM7dDHln5nJMoyIHrViPYcVmOAE=; b=Dn+2nrFDQKrtiNq9ga8VPS9XghL+cNwxNtGPRO1/jQaUPo8EW4mwabVL67lhil8V3IoH dnToTLcEwnVjbp+Ucf9g3QbVvZzjztcW3jgm2fZhJKjvO1Y8KizVtnGLOP4wRsVI9alNd QI9u+h5mZ+vrLvJZKAdalNRAyGlecwMJ6hmaHhdHoNc5OVDMJ+f2Sdhqnx7FAtEHB7ZHf RVSTZf0rrmnbsKqsZKM299Dmy9NZHdg+KcnOIPwha60wHdE9wooIVNApZnPtApfuIQ2Ak GLUxrpesQHjjrXG9WI2O8/jKtwLojQUv14YM6GWeb2jOEaa6TNOkpO7+ZYPHab7afng== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass header.d=netfilter.org header.i=@netfilter.org header.a=rsa-sha256 header.s=2025 header.b=DIovl3Sk; arc=none smtp.remote-ip=217.70.190.124 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D5162606A883; Fri, 13 Nov 2026 03:13:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org D5162606A883 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.a=rsa-sha256 header.s=2025 header.b=DIovl3Sk DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1794539579; bh=VwXdHxOfjvzzynD1vM7dDHln5nJMoyIHrViPYcVmOAE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DIovl3Sk1UzsB3L2t+V0y09VzZ7e5fvtQYZjyyQwaLVjSXqKopwZRIFk9F8GhuLPy +KGmHhD0Q5q8eqPQwQKyp/h75GHQKBno8JPMbTYWQGgfV9Qclzu2cE6W2aSRPZ8+x4 eZaIH8QAU6JpuvdSvzIkUyP2ZN3NNv1npeXihlpvkA1RvPspuZl1AUnGZVFD5qb1bl 4ZlYUeMZNNN6tENbr517fda19aW7g25FZfEm4hW0KUG9APtFbwq5je99ZSlAzZLisg PL4AQ6X7Xm4jB6elm8YRjRAWjSMiSCzzSTTZB4k+oCuPtDyM+wvHZqaFwGKTGoZj+B T9IBaGefG35qQ== Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 9486E602A6; Fri, 13 Nov 2026 04:12:58 +0100 (CET) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@kernel.org, horms@kernel.org, fw@strlen.de, ja@ssi.bg Subject: [PATCH net-next 02/15] netfilter: flowtable: fix pmtu discovery in nf_flow_tunnel_ip6ip6_push() Date: Fri, 13 Nov 2026 04:12:38 +0100 Message-ID: <20261113031251.2437074-3-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261113031251.2437074-1-pablo@netfilter.org> References: <20261113031251.2437074-1-pablo@netfilter.org> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Lorenzo Bianconi nf_flow_tunnel_ip6ip6_push() invokes skb_scrub_packet() before updating the PMTU. skb_scrub_packet() drops the skb dst, so skb_dst_update_pmtu_no_confirm() finds no dst and the PMTU update is silently lost. Move the PMTU update before skb_scrub_packet() so the inner route is updated with the MTU advertised by the tunnel dst, as done in ip6_tnl_xmit(). Fixes: 93cf357fa797 ("netfilter: flowtable: Add IP6IP6 tx sw acceleration") Signed-off-by: Lorenzo Bianconi Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_flow_table_ip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 19cafae748ab..644e70fd6773 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -699,10 +699,10 @@ static int nf_flow_tunnel_ip6_push(struct net *net, struct sk_buff *skb, if (err) return err; - skb_scrub_packet(skb, true); mtu = dst_mtu(dst) - sizeof(*ip6h); mtu = max(mtu, IPV6_MIN_MTU); skb_dst_update_pmtu_no_confirm(skb, mtu); + skb_scrub_packet(skb, true); skb_push(skb, sizeof(*ip6h)); skb_reset_network_header(skb); -- 2.47.3