From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr2-f8.google.com (mail-wr2-f8.google.com [74.125.225.72]) (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 239643AAF76 for ; Sun, 4 Oct 2026 14:01:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.225.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791122499; cv=none; b=t36wZOTwzTU07EQIuaxsuiIWhJgqMAHI3yC0xGR+B5KYq2aiBOw2GKAivytARmMvnfRCCSP/IA9Oxu4LcSlhLxgeLwnKP+bvXbdxBkR1Mo3fn+PzKy+V6nwctJeU0I7Gp9mdJQECeMyRtX8TlI2mAiHI92M8MxuHfS86TnErL4o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791122499; c=relaxed/simple; bh=KE2VmvcgzRzsohaFalSlwnQNko9IVpTrrNAyx5LHuyY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nyJv4R9iVsu7cgp7ZZf0y155EI5lH2G7QgFQdOwMxY4YXoimrEt9pnV/vMVtO+P+3+3g7h4OcjExeKOT3/Mcku3aumutozylZoLdDIr0Q9aW8PGhe9zpC76Jq3Za/MjWVCFZpQ96HGQF6bsJlFMGsnNtgl0JGABPQomV8lP/5Rw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=blockcast.net; spf=pass smtp.mailfrom=blockcast.net; dkim=pass (2048-bit key) header.d=blockcast.net header.i=@blockcast.net header.b=phmghlLS; arc=none smtp.client-ip=74.125.225.72 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=blockcast.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=blockcast.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=blockcast.net header.i=@blockcast.net header.b="phmghlLS" Received: by mail-wr2-f8.google.com with SMTP id ffacd0b85a97d-48b007d7d2cso359651f8f.0 for ; Sun, 04 Oct 2026 07:01:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=blockcast.net; s=google; t=1791122496; x=1791727296; 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=+t3C+Ja2CFaTDIBFicfkFdbgjtRqzlYdCsfo/CBmKMg=; b=phmghlLSJkI3H3iSSBw3OChHW2O2WhqHWlFdENK3fr46De+zJsx17yB9RStrkX643W Wd4/6Z7ymdrXVFGcRkBBfKYv4YiZALeI/qJYuA6kyoimXo3QzeVm3QAYHpiFGK5waVp1 Y4XjP6UWXnYETtVAYu9c98c/xgvsyQvEOv109ui2GruRvG/WDmB7mQSMyL6VdGTWyefg owat9LxruSd2ywuz3OmEWfUThuIo1oZ+6K/2tPcP9g27qmJWbeSwRZ4GzsWXB//eUMX7 PFuUTFrKdJHn75VA15oEFnF1lMULSQd/WdNHzrXorSqopkoJsPjtP5PJ8jcgj+pED3xi aj2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791122496; x=1791727296; 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=+t3C+Ja2CFaTDIBFicfkFdbgjtRqzlYdCsfo/CBmKMg=; b=r7NYcNN9yizcUemuPTqaGqXZr30MYv3HLDiAN//L4+SBD1c7XdlPF8gC08xRMDLH9v ynKJKYNgb+EbckoXXita9EdCRBdqOcpPXkuwY9mPk44bc/l9+rlGIwLwfkLW3A10KkaB XBgsH18l8B3pBFkbnjht8+XBP7EkCfWpBbuMKf2+jIu1mi3RsbSpueiXINAZoHjVesnu 0vcNixJXe5dD/5x617SF1YD8uuR7Ecg2tdpR3AJ4roeNxOYkBBDT1bZDzfXy3U8uqnWw 6NT527tkWn/TR6sSAPHFT67ynYkjv2cgVxh9EsaD2107NJYuXi+NoXs19+G24VNzIi15 QZeA== X-Forwarded-Encrypted: i=1; AKwUvBwi9lXOFsirsMF2xxPCeJuUhm3cxOdh35NuqLITNwyLaEqu5g5koGIK+8FvZOo4OODZNnnY5I8CY6D9VLE=@vger.kernel.org X-Gm-Message-State: AFuF++n7yQoT2UYkwmXi+ITmVGb55o6Rlthbg8s8Nu43H+zkwH7C2GJi d5zJ2sHvHGYbDsZkrVt0dSWfQfYlX/os3BHBMQuOM8PKYdjsu9Okn1RJz81au1Y46mM= X-Gm-Gg: AYBFou0m1fFlqEMQdMQXzeq4xrC3tiggnmho44f4gjlmWTkaiTtSaSRHMAlpW8AjdgL FOKKwMoHz5Jx6bJeWUTobnt3ngolqjPyJGmf9gkEDzjnS8x1PmZGLszG+ggE7BgIj5nGNZlQTBw OJOkvi5bBiDK6lGmlfFKxHiTGgNLwSoC+ynpiHGvPyfNcEADs2Ezq6SrUXT52fB/Eo+IKE5p0BO HybrqgJZbihKMx16LqMLgtZ1y70z8QUsuT2SeOFgGbL7NbA3ltxfXdVBiHFZWbxyrszKoAK9/lf x3AkMv42xarmUE3Zxg+Ni9hhC87tLfEQ73klw23D0QhgxS0Gr+R7H2d3hFhR/Be3poget2pMJWm fq8de3qs78QKs/mFNfWcnzV0KgGdRseNNMjOScVjY3l+xAxCa6et/5VxXA3BSZCZrpyOgKg8Z3j dxIWpU4O4M9hu9eEXF2sYJfoIC5UYeoRgF+yLw7/QtY7ON/RRG+dQDHBqglSiKUBUDb5X2mTPrm pJbqaLCj72LkQyh2xb8g+wzeWAsJU3QNs9lwQ5GuHqyZvGLdc4EM8ESoVb6f32ACAmXLhDlaG7W X-Received: by 2002:a05:600c:3e14:b0:49c:fa20:cc00 with SMTP id 5b1f17b1804b1-4a027585559mr141267525e9.23.1791122496260; Sun, 04 Oct 2026 07:01:36 -0700 (PDT) Received: from localhost.localdomain ([197.51.72.2]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4a039505568sm226480455e9.3.2026.10.04.07.01.30 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Sun, 04 Oct 2026 07:01:35 -0700 (PDT) From: Omar Ramadan To: netdev-bot+sashiko@kernel.org Cc: Taehee Yoo , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Shuah Khan , Simon Horman , netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v2 1/2] amt: mark relay data as a UDP tunnel packet before sending it Date: Sun, 4 Oct 2026 17:01:23 +0300 Message-ID: <20261004140123.94341-1-omar@blockcast.net> X-Mailer: git-send-email 2.50.1 In-Reply-To: <179106416186.434549.2202047416681649119@kernel.org> References: <20261002212458.34247-1-omar@blockcast.net> <20261002212458.34247-2-omar@blockcast.net> <179106416186.434549.2202047416681649119@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Sat, Oct 3, 2026, Sashiko wrote: > Should this have a Fixes: tag? No, on purpose. Eric asked for this to go to net-next, since the bug needs a non-default setting: "Note that tx checksum offload is off by default on amt, so the bug would not trigger by default." "A better fix would be (for net-next) to call udp_tunnel_handle_offloads() in amt_send_multicast_data() like other UDP tunnels do" https://lore.kernel.org/all/CAL4Wiiqw_7Mxa5W1EQgw2=KpJNNxG=cBLXsHvpio29GvD1UKZg@mail.gmail.com/ > This is a pre-existing issue, but it is closely related to this patch. I have not reproduced it; so far this comes from reading the code. It would need rx-gro-list on the relay's ingress device, and tx checksumming plus tx-scatter-gather-fraglist on the amt device (all three off by default), and a GRO aggregate that passes ipmr's DF/MTU check. It predates this patch, and the cover letter already lists it as not touched and untested. I will send a separate fix for it once I have reproduced it.