From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f48.google.com (mail-wr1-f48.google.com [209.85.221.48]) (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 52D54CA40 for ; Sat, 8 Jun 2024 08:05:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717833917; cv=none; b=jGxRVqMJry57HfkGraSe7c3ZVBLnPjseV/xPUWDnnh2pycpVbX/0m1LcQx8QoytXVPiTaESmAh9vnsioaW0ubaj2MSC9zjRzQ9/bxTs9seDeRMTuLIPHxCIdXR8TDxLDap74/JTGmNVqdntZt+WsX8bt5L/tjjCMYeGH8P82umI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717833917; c=relaxed/simple; bh=APRhzOIJ7x6eZpRT+NQUfIFNeuNwCdIi2tW7Cm1PfZM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QoyFUNGfqBcH//eRWzmttohvjRzTcJsOypr1+7VU8j8CsXSiiCoWLjJ5UIDqC0tOhgqD8v185ETcmotqu6Ku6IYYtxbbSPf6d7WHj7xFCtEzs5v8WwR0miVrrhLGGZjMhMwXTVtA17lDK30d/KkgBSkGfA6ucWO/roRphHBQvEw= 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=guyy3sjb; arc=none smtp.client-ip=209.85.221.48 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="guyy3sjb" Received: by mail-wr1-f48.google.com with SMTP id ffacd0b85a97d-3579ef2d436so124753f8f.2 for ; Sat, 08 Jun 2024 01:05:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1717833915; x=1718438715; darn=vger.kernel.org; h=content-transfer-encoding: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; bh=APRhzOIJ7x6eZpRT+NQUfIFNeuNwCdIi2tW7Cm1PfZM=; b=guyy3sjbi38OwCet0Xn9zV43/OrygYoiHBwmF5pA7o0GiI1hgzPA3DlyM5RT39MVKE ySJs7JNMvWneBhgiHej7mXNK3eQcpSvo0TIn22vZsDj63K23lqPBcdmjW6iYRAluCT4m xbb307cnSMU7nug/K3Enwb42orK5pxD2lKP42be6lDJU3d7VPVVIlz4zH8EcKoy3UFMN 9oxg41YfpdNo0IrEJF4EjtKFHAQX+NfDTPqFQKuPWk44KiTV0ckSarKH8DbXLrgqwiqa ykBBvasBjf5MzAzsCca/FluYLhzO7oiIK9WoWGtiwmvEyuFTx5B6oZS0AucrazRkuJ3v hNow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717833915; x=1718438715; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=APRhzOIJ7x6eZpRT+NQUfIFNeuNwCdIi2tW7Cm1PfZM=; b=BKLaPKfjMKnZGuDmY+psBM63ziSU0hNLbbCThqoOaGgREiFUAmdJcHlttB2UBDpbFV TbQw43fdMb6KeJpQoEBTPeCWFECVRnmpP82/3FphXgYcUbeNRUOLiyVImW+jMmlsnxjw AwXg/PG174aWTv8aVAh5qHHS2qcuHzbHNbWb2/7ccPOPA9CMvM1qwYoyqgcFyHWwusNR ja9yDM1YcFuYXRoYILzmWN/wbUhR5VpCOZjQLw2M9g/ylyBSuasNg4B2hvq2yjQXQfsR jrrhxSeTbXkM12wtdicCHypyQm5MuAJr+PZmMJ//FiGJrJkUkixoEmmEtGYBNzcANLjI ZlWQ== X-Forwarded-Encrypted: i=1; AJvYcCV4eyDTvolC1McRMBblWWItuPwouKBqyX94Iy/kySAgAx7gDbWwyy++KA1vN87cv1twK6bEeCAxGmzxAZAG/mn0Z5bQ14sx X-Gm-Message-State: AOJu0Yz/5akIfENvHEJ5aAekSNdK/qtcGt0H1NLVqTmKM6JUblQH2nma iHBUC7qhOmy6/8WJmNPQU3OMv1Oi0gIfvVDi+Ep3IUjEV8ExgP4YXTeGPA== X-Google-Smtp-Source: AGHT+IGLR4CH5vKgALCYJii0ToaErWVzgpIWV2Q+4xz/TXyB5THOq/fGfA2BnTZqgCe9bhC3jTSZSA== X-Received: by 2002:a5d:6c65:0:b0:354:fc97:e6e3 with SMTP id ffacd0b85a97d-35efee1d38fmr3324528f8f.5.1717833914579; Sat, 08 Jun 2024 01:05:14 -0700 (PDT) Received: from [10.0.0.4] ([37.166.160.110]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-35efe03596fsm4135955f8f.96.2024.06.08.01.05.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 08 Jun 2024 01:05:14 -0700 (PDT) Message-ID: <541b6a89-bd1c-4e7f-a694-392649dbd778@gmail.com> Date: Sat, 8 Jun 2024 10:05:12 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] net/sched: initialize noop_qdisc owner To: Johannes Berg , netdev@vger.kernel.org Cc: Johannes Berg References: <20240607175340.786bfb938803.I493bf8422e36be4454c08880a8d3703cea8e421a@changeid> Content-Language: en-US From: Eric Dumazet In-Reply-To: <20240607175340.786bfb938803.I493bf8422e36be4454c08880a8d3703cea8e421a@changeid> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/7/24 17:53, Johannes Berg wrote: > From: Johannes Berg > > When the noop_qdisc owner isn't initialized, then it will be 0, > so packets will erroneously be regarded as having been subject > to recursion as long as only CPU 0 queues them. For non-SMP, > that's all packets, of course. This causes a change in what's > reported to userspace, normally noop_qdisc would drop packets > silently, but with this change the syscall returns -ENOBUFS if > RECVERR is also set on the socket. > > Fix this by initializing the owner field to -1, just like it > would be for dynamically allocated qdiscs by qdisc_alloc(). > > Fixes: 0f022d32c3ec ("net/sched: Fix mirred deadlock on device recursion") > Signed-off-by: Johannes Berg I found this quite by luck. Please CC maintainers next time, and blamed patch authors :/ Believe it or not, I do not follow netdev@ traffic. Reviewed-by: Eric Dumazet Thanks.