From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 6ACA1242D89; Tue, 8 Sep 2026 02:41:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788835267; cv=none; b=CL45P38gtusb7uJOhQqma7/haU4DIgD7VKYB/OHMYOLwPf5rR0IVc8SiB+wGtYajuxHWrDY3vFtxnfSt4RykmDEkligiy2IY+MOXsJ6Ch3zg5tfH0Ryhc6hTyW4t7P4hr89GjF4BHvqphff5BxoYchnHp0sEZ2Wp46ADW4QTEzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788835267; c=relaxed/simple; bh=ZXqt+wy1ky6ZkROxbET0sqVfnQl0tHsSIP4qR52I/FQ=; h=Content-Type:MIME-Version:Subject:From:Message-Id:Date:References: In-Reply-To:To:Cc; b=N39VBs2PD2aYNm3EmjxXL6qcu8vqE20NEBwvgnr50Hwki2yNByvwHSoIltF1B1zBtTATVulG1qiLV1THfphEI4laa5IOMtrCh1G30heFKAhdmmH5Pjvil0lKC+hU7mZDDs7kjxcoCWRtxQe4U6kO1YM8oM34gwf5z9LC/OQqI5s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DyUcpSHc; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DyUcpSHc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED9C11F00A3A; Tue, 8 Sep 2026 02:41:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788835266; bh=tvhK03jSmFF/rODjpwj0Aw9zx73Sq3WpGLz8+mDMcYk=; h=Subject:From:Date:References:In-Reply-To:To:Cc; b=DyUcpSHcf00sQZ9081E0Rx2GtFR7Mdsd0Vp2WYvAbibs7CO6kde6AWnGfkCluiIL+ vIk7oAK4WDmp0jFeXoVaaOWeFhGvm34cnJtH4hkH2B5anjtItgoJS6d0z5VjGBEjMI jIN4sOSDHnvMkBI7jQsGtb3YHAzFM5EoiX8FaczGODhxZbOvk3XawgBnDqrFP1N7La J1bQDtEm1oRrEw74JFCZIkZu8d1vsyFIDsHaNShZrEuup8h2V4IPzj/OeU9PEX/VTe 4nnNCS2PFNVUV2LG7JubgHxhDyyhmryJ6dGzAnlOZbLbtsxXocKkoDHESkbL1V5mhC CkdWw9dT9HPHA== Received: from [10.30.226.235] (localhost [IPv6:::1]) by aws-us-west-2-korg-oddjob-rhel9-1.codeaurora.org (Postfix) with ESMTP id 197AD39E8A5D; Tue, 8 Sep 2026 02:40:06 +0000 (UTC) Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH bpf 1/2] bpf: Fix bpf_skb_change_tail wrt csum partial skbs From: patchwork-bot+netdevbpf@kernel.org Message-Id: <178883520489.3252445.12614070456129437426.git-patchwork-notify@kernel.org> Date: Tue, 08 Sep 2026 02:40:04 +0000 References: <20260907121025.1923656-1-daniel@iogearbox.net> In-Reply-To: <20260907121025.1923656-1-daniel@iogearbox.net> To: Daniel Borkmann Cc: ast@kernel.org, memxor@gmail.com, yusuke.suzuki@isovalent.com, tom.hadlaw@isovalent.com, bpf@vger.kernel.org, netdev@vger.kernel.org Hello: This series was applied to bpf/bpf.git (master) by Alexei Starovoitov : On Mon, 7 Sep 2026 14:10:24 +0200 you wrote: > Cilium generates ICMP "frag needed" replies from BPF when a LB DSR > packet exceeds the egress MTU. The reply is built by first trimming the > packet down to target size via bpf_skb_change_tail(), and then pushing > the ICMP error headers in front of it. > > The trim is rejected for skbs which carry a checksum offload, e.g. TCP > packets aggregated by GRO on ingress where tcp_gro_complete() leaves > the skb as CHECKSUM_PARTIAL. __bpf_skb_min_len() raises the minimum > length to the end of the L4 checksum field, so a trim to 42 bytes bails > out with -EINVAL given a min_len of 52 in this case, and due to that > the ICMP generator fails. This is not the case if GRO is turned off. > > [...] Here is the summary with links: - [bpf,1/2] bpf: Fix bpf_skb_change_tail wrt csum partial skbs https://git.kernel.org/bpf/bpf/c/3b55f350c68a - [bpf,2/2] selftests/bpf: Add test for bpf_skb_change_tail on csum partial skbs https://git.kernel.org/bpf/bpf/c/15e2565f1c43 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html