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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 DCF13C433DF for ; Sat, 4 Jul 2020 16:37:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B69BA20723 for ; Sat, 4 Jul 2020 16:37:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DnNHdo+t" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726964AbgGDQhS (ORCPT ); Sat, 4 Jul 2020 12:37:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726632AbgGDQhR (ORCPT ); Sat, 4 Jul 2020 12:37:17 -0400 Received: from mail-wr1-x434.google.com (mail-wr1-x434.google.com [IPv6:2a00:1450:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7941FC061794; Sat, 4 Jul 2020 09:37:17 -0700 (PDT) Received: by mail-wr1-x434.google.com with SMTP id z13so35936068wrw.5; Sat, 04 Jul 2020 09:37:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=NGM5We0s6d91iAHT6ccX0Y+8JiIRTw5ExhXAZd/KucE=; b=DnNHdo+tr+7acCeB3NZNGPinQRrKbRX81uLIAqtL5Hkt/3NH6jV4gGOIFxZUdhPXJ3 VPaI3R/0RsZ7/M9+bOEWBDmBixytA1fLy5NFct3WKqZfjVzWaWOXA7fuKI3qWCRUU8te urDZtriR2Xff+nOwTMemCtle3CH2b/MRLP2OHXjPLdKcqfZWpbUWezB3y5Q9k/azKuFC TJWcfJNHW1DTRx/rjXUcxD23vts4lMFHuaLDd3T/7MOPIFWcxft2CQHL4+ymm0neAX5M CmM5LCfw392tt+EEnwsm0wiNQsP/u7Mb0AEudQgZFrKnqVpT7YisWpBYRnmdqxK7ieze z2sw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=NGM5We0s6d91iAHT6ccX0Y+8JiIRTw5ExhXAZd/KucE=; b=iLraqFrha4TeGfgiJ73PveAwF5TT3SxtL5kUA0NvpSpzrrELJEyr1JFU3d/QI680V8 EDI4T1QnAhZ5+KlWvOmtAFFvykhkO/JYUoPhkvLlzQ42dK4zXBdg/+Ybk1/4xC/uQ6IW SYOUU44eVbuG585XP72D8LX6iYNkdB7BKx66VfkEAt7FCYF125HPnY0g5HKyTXRs/OoF CBSjPngyTue9pAe4JH3M3KKNd2bggCBBe2XajE1ZxRmwLtqszIJJVjAFRVlootQMVxc0 S+soh0Qz4tVAmz0f9eri0B5EUPM9FjsdaAfl/+6OuAbpYveMIWEd5za32Yq4TlWjL9N8 7zXg== X-Gm-Message-State: AOAM532ToqLM/s1PrFQ1qthBc0/0V6f+SUw3cp4tjlDhi7izfPHkmG3J xcafwTQgq2RPzNb3EpLZV45CLI82EYL1q+A7jVSKjw== X-Google-Smtp-Source: ABdhPJxCG5R263EDYCqlklp/8pFwN2e0CRcdTF3YD9+FvcUrMqsic+O84r6XvCvWiGvxyIUtusxMqbrPX6uf876EGvY= X-Received: by 2002:adf:ee0b:: with SMTP id y11mr18837573wrn.360.1593880636134; Sat, 04 Jul 2020 09:37:16 -0700 (PDT) MIME-Version: 1.0 References: <20200703182010.1867-1-bruceshenzk@gmail.com> In-Reply-To: From: Zekun Shen Date: Sat, 4 Jul 2020 12:37:04 -0400 Message-ID: Subject: Re: [PATCH] net: fm10k: check size from dma region To: Alexander Duyck Cc: Jeff Kirsher , "David S. Miller" , Jakub Kicinski , intel-wired-lan , Netdev , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 04, 2020 at 09:05:48AM -0700, Alexander Duyck wrote: > The upper limitation for the size should be 2K or FM10K_RX_BUFSZ, not > PAGE_SIZE. Otherwise you are still capable of going out of bounds > because the offset is used within the page to push the start of the > region up by 2K. PAGE_SIZE can drop the warning, as the dma allocated size is PAGE_SIZE. > If this is actually fixing the warning it makes me wonder if the code > performing the check is broken itself since we would still be > accessing outside of the accessible DMA range. The unbounded size is only passed to fm10k_add_rx_frag, which expects and checks size to be less than FM10K_RX_HDR_LEN which is 256. In this way, any boundary between 256 and 4K should work. I could address that with a second version.