From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f52.google.com (mail-wr1-f52.google.com [209.85.221.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8B44C3A4F26 for ; Wed, 2 Sep 2026 19:53:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788378796; cv=none; b=kgVKbv5kPL3Zb09EfHnfuHe4KpekL1WRiZlc8af2VjtB3bIEUKm4bj/eEupRr9PF+BgO4TX6MkHpUHYvH8nMUPgHMwK6MD54KuyfIWmAr066EwE0RjhVfhW5dYUwYI746Q7q5/TOqG7Ov0JMf9w/swkhhma8QXhM2uffw0K/fgY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788378796; c=relaxed/simple; bh=vr6W5zFpVz8w0VHMme/yDcx9OPftCRNIo4AFcnhZPtA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ar7HJIYzqipojzM3tdwB5ze9iU0TIkN/1JnybkTaQa1u7GkxmLXxJ5yz3yDG87W23l68KB6Ksq9wss8r+dofVSYTDyXjnzT1w1V0j+IlZtbs0QexhqpTOebCm8fAWmZXZRy1BOMQg+LVXpiVMum6JIjpu/vVKOBt5V0y+VZ8Zlo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=FpD1KkVR; arc=none smtp.client-ip=209.85.221.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FpD1KkVR" Received: by mail-wr1-f52.google.com with SMTP id ffacd0b85a97d-47fe89fb333so1001469f8f.3 for ; Wed, 02 Sep 2026 12:53:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788378786; x=1788983586; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Uw/w31b9K+Bo5B9bJ2pBdij1/BOB3D6uwkiUGcYBOoc=; b=FpD1KkVRQ6ip1P1cfhHQc+TUFKZorOz2rEkEJiN9sxbO9abeWr+Az0MR3bKe5yvYhK /EE/ylsBdQQNYDD1Gzc0jGRixN6E1DGHSETBJrJDRbtuVrfMiMDAkXv4WHiB8wYNuksq i8SlVEHcxoaB5oLHpSgTCVPLlnaVQyUZOZTF2t3hN3riC+VrcxUpeNq5zQ5i2pXf8n95 /brTAPQtOCJyQQzoYUcpvTRMjCLzusxniEzvBg2Mlw5Fp87X8v77I8AeDBmiiLz2blUo Tq46VgPNvyPVrg5yJjcE+GEyPSNeZ/Cxs2wTevFXD2s/0YZWZ9PjIDvlHkuXA6xjLVVC +O6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788378786; x=1788983586; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=Uw/w31b9K+Bo5B9bJ2pBdij1/BOB3D6uwkiUGcYBOoc=; b=MER4EGXAJ5oZH1RD7vBBF5K8M7QbVWhEiC4cTUQKg2YPZAohTivrY8LtnZbY128M9e 9PlpUpXEtdS108JuhwtABm3JgZGJ4Xc1hpkFnAv8jeuVLHL8flg1gjIhtyT4TYjYNqal nfer+AoqjKKhAimd9S6vuL/HarRQMusDazN0CUECQNZFQUF0Ehmpi/8lMvuE1Sf+6x1k tdZzKS724s/u0ZGfkPhVODzlsrEbQU+2WT46I2iaytXuPlsfM4n6ULdXEIgp/efOqfdW Kr0zc2dqa20TfmXVzVHul9WMKlWD01VNgHPzOIzAafy2qgc07dgjAGfbGm1uYlSoBnXH 9lww== X-Gm-Message-State: AFuF++lk1NGKbx3Ffbyn825fE4Dof76gE9O3w5Z3DU4CLG1ywE3LM+Js iWajhLt70mKJbN7/1WstpjfB1IJLJ64sENgaUaQc0NPmPvBH8CSU9zgd X-Gm-Gg: AYBFou3b4AfWhNsRMODnOY3fPNvxvZ+XIrNfimGxMh1QQz00HtA//7VV6AX+FPCZlOg Wv+e10K3FP3bekeGhm4lUgM6WB2AkOSFdrz1jXQqU7aK6M2lqCEf0WRrvQk5iI+vodJ2j00xzRq S5eJGCbA/GKeUhpFl34IoqnokxEooiya6pMiZkR0KE1eSRjjDUdEkSEl1zqFGbuDIWTSi8Hs4B8 BLrJtIwuE4ZgePo/gRkIvLJzTRwy+Y/INOt6mb10Q1gr2tt0fKDlaoYnsdyk+yFgpSZHseS1NZk 3K+OXfa1WBfDYmwErv5M2yiJgDvsNilKkDhGYQP2wTv0n5SKBgM7GPtz3blm8Wvv7XNmWaxqV83 FPCd8dkTqtLZ0UBiCOjyOrtuWEyXwkpE6aDVe7T0KCQO9hPiEzLzTbTv/hCx8EB0vuyKo+vpL9e FjvF7r+vBE2D2CFvzL4P0MOG8hdeuGgaskMCRwbeW2Q8TDeZHsT4KRQxrd/ZvlkpQ= X-Received: by 2002:a05:6000:701:b0:484:3600:35b2 with SMTP id ffacd0b85a97d-48488f00a25mr11965360f8f.5.1788378785721; Wed, 02 Sep 2026 12:53:05 -0700 (PDT) Received: from gentoo ([45.150.111.164]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48448ed30c0sm8552779f8f.24.2026.09.02.12.53.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Sep 2026 12:53:04 -0700 (PDT) From: Yaroslav Dudkov To: Ido Schimmel Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, dsahern@kernel.org, horms@kernel.org, aconole@redhat.com, sbrivio@redhat.com, gnault@redhat.com, laikabcprice@gmail.com, rough.rock3059@datachamp.fr, stable@vger.kernel.org, Yaroslav Dudkov Subject: Re: [PATCH net] tunnels: Drop stale dst when building an ICMP error for PMTUD Date: Wed, 2 Sep 2026 19:50:10 +0000 Message-ID: <20260902195012.265628-1-aroslavdudkov622@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260902190112.4126199-1-idosch@nvidia.com> References: <20260902190112.4126199-1-idosch@nvidia.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Wed, Sep 02, 2026 at 07:01:12PM +0000, Ido Schimmel wrote: > Fix this by making sure that the ICMP error packet does not have a valid > dst entry, thereby forcing the IP layer to perform a route lookup. Tested on net with this patch applied: - pmtu.sh: all 16 bridged and all 16 OVS subtests pass, both with and without br_netfilter loaded. Without the patch, loading br_netfilter makes all 16 bridged subtests fail (the reply gets delivered and exits with the old -w 1 failure). - The forwarded-sender reproducer from my earlier mail goes from 10 tx / 0 rx / no errors to 10 tx / 8 rx / +1 error, the error being "From 192.168.4.1 icmp_seq=1 Frag needed and DF set (mtu = 3950)" -- the tunnel's PTB reaching the sender. Tested-by: Yaroslav Dudkov