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 EC0C21A5B9E for ; Mon, 19 Oct 2026 03:20:06 +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=1792380007; cv=none; b=WirBMJai9/xwgzyGq+91EqopZDnMU9TAUmVeS+QwkfYPXbS/vqeZKy7efHmnAwxBHDMA97U+4PC6KHT5h2I7cJ8zer4opXMxi8WO3q2eID6UbFpxzRXWHsRBkAV8HsidPvHUQvQ5oLqUza7SHuPPh+Suax4adT0AKgwrX5N0yIQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792380007; c=relaxed/simple; bh=IFVfxjQxKtprexMLryFM4c5uw9/z+FyriwaFY1t1FNE=; h=Content-Type:MIME-Version:Subject:From:Message-Id:Date:References: In-Reply-To:To:Cc; b=cRTnJE8St4eIt4OuYhk7IkfXixEhQJNQ8505zKtgqn/1J6zYJMH633vntAAm0hoXx0F+G5NL4RT4uGk66NXP7G5gP6HHKmo0yLVZT0ZEB5E829t4MlW+bjMdIU2NIC1DPPYnt92mPEDCRacAGnFlCqmf1qQFhgn3ONPQGvKnNyQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XTg3IXNd; 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="XTg3IXNd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7FBFB1F000C4; Mon, 19 Oct 2026 03:20:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792380006; bh=4hNbSkfwTjE76ERCizLwz+fwXI+YvoxUtm5aJzkFdjw=; h=Subject:From:Date:References:In-Reply-To:To:Cc; b=XTg3IXNdCwLNfw7IHw3DCYdnTBgYFeQ3lRoPmbNYtY9obQ/MIqKSOMaVTGXV9p1Vj Tregd06J1e5u8BAc1zHsftmbYafhrIyTnQyJCP+s5o0z+gsrAkTs8Q7pwsVk3wKwOL gYxg+cdPFJTreW2lSDzJhBA2QMddX4PhZNV7TXTPMATBZ4EjJRECvrsFrhaquF46HM tPJrtQ6tj0OuEWI4OXr5mITLwCSo/evc0yuxDnfZVUXns6ws5XP/80kEfEGh0jZ9Kl paSvweR4mRy3zGLlIULmT409TIPl6uytqxwcMflcUXuYr8SL6zjTlXNDbtj9SdWAZN iGiZvwjYL5RRQ== Received: from [10.30.226.235] (localhost [IPv6:::1]) by aws-us-west-2-korg-oddjob-rhel9-1.codeaurora.org (Postfix) with ESMTP id 7735338119C5; Mon, 19 Oct 2026 03:20:06 +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-next v2] bpf: Refuse the prologue for an extension if callers keep packet pointers From: patchwork-bot+netdevbpf@kernel.org Message-Id: <179238000530.2381645.9304275221355856446.git-patchwork-notify@kernel.org> Date: Mon, 19 Oct 2026 03:20:05 +0000 References: <20261019011328.1843764-1-alexei.starovoitov@gmail.com> In-Reply-To: <20261019011328.1843764-1-alexei.starovoitov@gmail.com> To: Alexei Starovoitov Cc: bpf@vger.kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, memxor@gmail.com Hello: This patch was applied to bpf/bpf-next.git (master) by Kumar Kartikeya Dwivedi : On Mon, 19 Oct 2026 01:13:27 +0000 you wrote: > From: Alexei Starovoitov > > An extension that writes to the packet of a tc, lwt_xmit or sk_skb program > starts with bpf_unclone_prologue(). If the skb is cloned, that gives it > a new head. > > It does not count as changing packet data. changes_pkt_data goes by the > helpers and kfuncs that a program calls, and whether it gets a prologue > is known only after it has been compared with its target. So the extension > can replace a global function that leaves the packet alone, and the callers > of that function keep their packet pointers across the call. These point > into the old head, which is left to the other clone. Once that is freed, > by the reader of a packet socket for example: > > [...] Here is the summary with links: - [bpf-next,v2] bpf: Refuse the prologue for an extension if callers keep packet pointers https://git.kernel.org/bpf/bpf-next/c/4f842631f178 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html