From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2321CC43219 for ; Wed, 1 May 2019 16:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2A062085A for ; Wed, 1 May 2019 16:00:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="mFi6QfPY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726844AbfEAQAo (ORCPT ); Wed, 1 May 2019 12:00:44 -0400 Received: from mail-it1-f193.google.com ([209.85.166.193]:39159 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726465AbfEAQAo (ORCPT ); Wed, 1 May 2019 12:00:44 -0400 Received: by mail-it1-f193.google.com with SMTP id t200so10461957itf.4 for ; Wed, 01 May 2019 09:00:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=UucgAJ6vzQAJLUd8MejiceLufM+Rh+s5b6O4bHFTuzI=; b=mFi6QfPYyieJqHPZQXRfHHQ3WBm3B47xy+U1F43tfa/c8xD/oCRdQPCyQLse59bH6u rwFxaZRlvWgrLjxkbzjWZCnOnkEig0rDmc3Ay6+aAluhblZIeD73A/psLZIWKxAe5SHb +QvghO18x5taI/6ZuClbSwGl9KeXfvSeT5BzMJc1FLpIKnHL9AvPC7We5WNkzFXj4djD sp0c1Fgni/+VNaUU47LWahauEpxwRgHOnbWR0eKuAg+/+Xp08ftFkikjjuTdr7lpxbOT nJ/8JPgYI2gtW0rfJ4umEbRIB1KMVsUA9QZxIviKsXyaaNc4SyLzhZK6+CpRji18Xt+H ir0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=UucgAJ6vzQAJLUd8MejiceLufM+Rh+s5b6O4bHFTuzI=; b=bYlVNbkduTX8jB5SJfaQOciMqzFVp1nwEwOPtLe0FQl/blvEuXTGrQLL7q59DsOj/s bFkdrbpOPP/gxfGRCsOOV5iSqKFYSJWsHkJCnpuE8GAseCoiE7fDxaACATSvXtEg/uM6 Nl9qEH6Jfe537B7KlSyrKxv//k8hjmNr7tO7Z+F0Y9OQghrbdrbW3B3thb3sKG8MAdxO J9cERzv/Td4uzy+nQADXiyYWfNysbiJ5S2UvRhBAIj8L6ELZnaMlkqLYKXMpX32EmjZv yvWhW6MfKf/nQHnPAC7kkMsOk5z6IJznGxmXmk5B5Q+Rs8r7CZ9n35j+S0namo6o5OS8 59dA== X-Gm-Message-State: APjAAAWM40BLmL8+mYHp3TFDPC0HXLT17SUup1NurumMokh4HVxJtHGm ITGRGT5PEdXIE4siha0tyMfTVhWMtxjHRA== X-Google-Smtp-Source: APXvYqyngemqaTJRtwt7edU3xJc85kB0kSghkkjs8I9dP2T+jLH2ib7wQ2eYqYgvb4dDcNdLhVepBw== X-Received: by 2002:a24:4290:: with SMTP id i138mr8362892itb.129.1556726443331; Wed, 01 May 2019 09:00:43 -0700 (PDT) Received: from [192.168.1.158] ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id 15sm3275504itm.6.2019.05.01.09.00.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 May 2019 09:00:42 -0700 (PDT) Subject: Re: [PATCHv2] io_uring: avoid page allocation warnings To: Mark Rutland , linux-kernel@vger.kernel.org Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org References: <20190501155916.34008-1-mark.rutland@arm.com> From: Jens Axboe Message-ID: <7c75a9bf-204f-1159-a2db-4679158652a2@kernel.dk> Date: Wed, 1 May 2019 10:00:41 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190501155916.34008-1-mark.rutland@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/1/19 9:59 AM, Mark Rutland wrote: > In io_sqe_buffer_register() we allocate a number of arrays based on the > iov_len from the user-provided iov. While we limit iov_len to SZ_1G, > we can still attempt to allocate arrays exceeding MAX_ORDER. > > On a 64-bit system with 4KiB pages, for an iov where iov_base = 0x10 and > iov_len = SZ_1G, we'll calculate that nr_pages = 262145. When we try to > allocate a corresponding array of (16-byte) bio_vecs, requiring 4194320 > bytes, which is greater than 4MiB. This results in SLUB warning that > we're trying to allocate greater than MAX_ORDER, and failing the > allocation. > > Avoid this by using kvmalloc() for allocations dependent on the > user-provided iov_len. At the same time, fix a leak of imu->bvec when > registration fails. Applied, thanks. -- Jens Axboe