From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) (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 51A44171B1 for ; Sun, 2 Aug 2026 12:33:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785673994; cv=none; b=W7ndcJJa2ncv2eR7ZmlV7cCvJ0TJFMh7WuB1XQ6QnYkQATiXVVWM4UBfnEaAokzRGXDhaXeQIKjO5mVKuRqj2j+aVE81ac48TW9lMMRp+/RhvMiy0WhMSSZulEDHaYKjq1MATFpaO2iWW+Mnrtt1/GgGnrU/ZRXbbLwxlaWh67Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785673994; c=relaxed/simple; bh=CqvVGKLWOhQZg6fkJf8NGKO+3amSVHYQ5JV3a8CpshY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=oZKnAqWP1NrP2XEuT0RagaFp77YalUpVejQx02xkTkz60lSSltl9MVHgKza2mFG8y/ePOzMcCiWUizMZJXtngQaOy3RK6v9gsSeG2FCnv2wI/M+It7ptO1Zae62fosdfz4ORweNdqfz7r0lrzG2wCogZyboD2tpxtSGfRSBobIQ= 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=O22K2qWE; arc=none smtp.client-ip=209.85.210.172 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="O22K2qWE" Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-8485b358552so2723973b3a.2 for ; Sun, 02 Aug 2026 05:33:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1785673993; x=1786278793; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=zLPXOlMQ3I1IqUDcfkevWnBWFBV8QBbEkwHgFssZeNM=; b=O22K2qWED4XFpp1RJWDgISeOObXVtblxrXQIpLGmOla3j/lhJ3t+lnfEXK00/4lo2q nbV/ioqMg4ohrDprFzu0otK/ONk6uTMqjPY2NDA6Pp88YhI6qXzcNpWqlgjq+6VzWypA 1IXOkymK1iDSG2xVIrJa5TCKsvs2rkIt+Wr1VBUXk6PVuSrenc9BU/ftStB92OnUNycz b0b2plq/0xE8NDOVGZBy1lCEBis1oNHUz6lcKqy/i3be0JQSjMLbTnVD4ry4A2xkE8lb YlJfuJR4jMRM0LQhp6Nv7/E/7GyWXnsLDxwuJWq8YnXFiupotTtBy30iRmcTuVMlpYpF xKDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785673993; x=1786278793; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=zLPXOlMQ3I1IqUDcfkevWnBWFBV8QBbEkwHgFssZeNM=; b=H19DAJbI1kDLOvswtQ5WqoxkpkiE01CZ00LQqYsfhVJzjAmcvJtFTR49vbjXAAYpJG VdY1TCUrwERSj5RUe8w0ZgTYM7wiBNC4L9G4mLlQUBAqFsxne/4OWOtBidR4MPkLtbjt U9nbzQDvsBZGZVMmmBdQoZADK7w8WtjEW20ahV+g/C+PbKFDFxt1Xw9hH/IB4jEqHkCC 773a6SymlGaF/XW4DbMhLa5lg4CfDb+7UOSZgRPmvE4QK18F0e5CeWjUwS/VTNbgZxZe bbFpIbW9zTa6qRAMzaCAzpvelmZOVM2odjQtMaUs8v/ugNKCb3jTh6ES6dk8UVlfgWa5 19wg== X-Forwarded-Encrypted: i=1; AHgh+RqCBx1erRdQXZb0GSr9vxbUNQ6TBgUpukhgOV/ioqsHkXYep8BO8UOMZnywAI8rCJSKcEXOQLz+qH5XxVU=@vger.kernel.org X-Gm-Message-State: AOJu0YwdTa+HLhTK8Ul+5wuneAi1PqjA42QWNW/S5cfBsGvFZwJjrvEt VNWPg+uyCaKt4wy6f6iN5KlWcnaIAB7Kud4eTphmh4aaDkNGjA56XJmt X-Gm-Gg: AR+sD10sYBoxz4joDDR8Il8OmrV43ikVZaoh6hCSJq2A5I3o43scfm9b1uQYQ8xmKY9 DluSIedhymcUVZsiujX+P2EjNmHIF15zNPNkLDXrofDSL75pioL9boZXmSQmmNmb96QiSVMCGKm rlA0IGBGM/nAQqU3YVPcDrUjAgjmN8Xr8kjtB/Kc2tEa8jb9OTVuu8V8Up/UfU2k+EjdGVJlZJw zYY/Qs7uhE51+IQsN/N7UsaWw013I6qENnda9EFk8KpDi/1I8cr+0SToFwCGhB1iGSi/lLH+zL7 ho531wOr8Mp3xeGw98TybqQCQnX/o9gl04cwSj33aRW5YLFbsa58ou0EvEjKwdgN/2ON8/zKKxf OHtjNFMQ0RafAafuLs029lA+MznDl9d13ehKadH7B9p3g/3xJM+IRDb3JSkcn4LlQPNTU+0Awg8 h+tjb3fUYvn+UcoZ1gtlr2jop4eBUMx8lCNuz/5kGcXX2r59kEm3LTedMz/NNQ9OBduNev1acM+ pOUFpbd5TpKEHPHZ1HOIRf2kClYVeyMOMlJQSQjtzwqLcCmZ8xDEdf5lkeyD2o0sZWLayOetZFx 4UaW+LBKKgzpgl16527P X-Received: by 2002:a05:6a00:1da7:b0:846:2f5b:c00 with SMTP id d2e1a72fcca58-84ee4903b73mr5347240b3a.54.1785673992675; Sun, 02 Aug 2026 05:33:12 -0700 (PDT) Received: from ?IPV6:2620:10d:c096:325:77fd:1068:74c8:af87? ([2620:10d:c092:600::1:b123]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-84edbd3a4b6sm2475959b3a.4.2026.08.02.05.33.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 02 Aug 2026 05:33:11 -0700 (PDT) Message-ID: <11a640b6-46b1-44d6-aee6-872107f7f570@gmail.com> Date: Sun, 2 Aug 2026 13:33:02 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v1 1/3] net: core: propagate unreadable flag in skb_zerocopy To: Mina Almasry Cc: Stanislav Fomichev , Bobby Eshleman , Florian Westphal , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Jason Xing , Kuniyuki Iwashima , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Jiayuan Chen , Willem de Bruijn , Kaiyuan Zhang , "open list:NETWORKING [GENERAL]" , open list References: <20260801125308.1342897-1-almasrymina@google.com> Content-Language: en-US From: Pavel Begunkov In-Reply-To: <20260801125308.1342897-1-almasrymina@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/1/26 13:52, Mina Almasry wrote: > When skb_zerocopy() copies devmem payload fragments, it fails to update > the target skb's unreadable flag. This causes the target to appear as > readable memory. > > Propagate the unreadable flag if any devmem fragments were copied from > the source. From a quick look, it doesn't seem like the function would work reliably with netmems even with this patch, but that's a different kind of issue we can return to later. Curious, did you hit this in prod? Reviewed-by: Pavel Begunkov > Fixes: 65249feb6b3d ("net: add support for skbs with unreadable frags") > Cc: Pavel Begunkov > Cc: Stanislav Fomichev > Cc: Bobby Eshleman > Cc: Florian Westphal > Signed-off-by: Mina Almasry > --- > net/core/skbuff.c | 3 +++ > 1 file changed, 3 insertions(+) -- Pavel Begunkov