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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 0FC1CC3A59F for ; Mon, 19 Aug 2019 05:50:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C3F5520851 for ; Mon, 19 Aug 2019 05:50:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OJC7NEqq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3F5520851 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4E0F66B0008; Mon, 19 Aug 2019 01:50:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 490BC6B000A; Mon, 19 Aug 2019 01:50:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3A74F6B000C; Mon, 19 Aug 2019 01:50:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0166.hostedemail.com [216.40.44.166]) by kanga.kvack.org (Postfix) with ESMTP id 182F66B0008 for ; Mon, 19 Aug 2019 01:50:21 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id BC357180AD801 for ; Mon, 19 Aug 2019 05:50:20 +0000 (UTC) X-FDA: 75838102200.15.brake78_775fee32bdb23 X-HE-Tag: brake78_775fee32bdb23 X-Filterd-Recvd-Size: 4627 Received: from mail-pl1-f195.google.com (mail-pl1-f195.google.com [209.85.214.195]) by imf11.hostedemail.com (Postfix) with ESMTP for ; Mon, 19 Aug 2019 05:50:20 +0000 (UTC) Received: by mail-pl1-f195.google.com with SMTP id h3so423393pls.7 for ; Sun, 18 Aug 2019 22:50:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:in-reply-to:references; bh=ZGbhnh/rQl26tl12zgYbAbZJa4C3RLtP+c9zSecEuwg=; b=OJC7NEqqIFckSHtMwvJvzoMvzR1HzZv8asknNEhBekF5AyaeMVFhfTN5aVT28rzsLS SfWI0BffYJI3D/kMC1pBkGlwWlRfL8chg19bQSe2fdIRvcnuL8oblwa+ItTYZSksVt/y 5yWTqRQu/fTmS3+G53PKfp+iG1Fc4EwjTbufaHqn84uroAGS/9sJl2HRSywYrrsZr+E9 lx1bQP2osZzYqlFocT9ZjaHQbYJkDywqhJAGGi8ErKQXIVuBBhX6MSoMXLkwvpS9LX6P Fe3MKHRz7aTiAlntaJTZ7hRiNaSZhM7ro++swZFdzpAhXe5vgHTa+/XsXGmIrvV3SP2I SSvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=ZGbhnh/rQl26tl12zgYbAbZJa4C3RLtP+c9zSecEuwg=; b=j9FiDmJA1TAZZDZIhHKgjm4IRw2oibLpA/LuSLd5ocvrIUmz6mLOg+QXpK2jQ2kWdw Iloq3rcdFosgrOLG2tyUYyWeWXKcv9N9sBhB5sGPgHUXJZmrFj5XgKztlLQg9sZTGiUY ZuTPJ+DO4lGYTjBNbLaySTu7XUBINu32dFbU039d/XENmq48h70vpyUxkb7cKAfaNTrA AelAEZy8JbZosicHhR8IyrrLymKLwNz5m4HZe88wUV/0zrVLcsZwxCr+UuCtpONzvS+y WccO52NzP37G9bBUL2FdUyN6ZMbzvePdcB/ME2xaQgHlwp0vigM6l90TGdjVHkK/Asci LL1A== X-Gm-Message-State: APjAAAXIo4ifvZRv3a2hq939Ee23iMdIIcbwio7Q0MQLDN1QGETZFh7k Ry2MODk+8mozTobhHGLGhhI= X-Google-Smtp-Source: APXvYqxSH/FK0cAT9ydQelCiF5nBAb0CLUwft1MT1K73dTBqypzuhAaaaMpUmvakCpx0tNtvy1W0HA== X-Received: by 2002:a17:902:690b:: with SMTP id j11mr21430996plk.35.1566193819287; Sun, 18 Aug 2019 22:50:19 -0700 (PDT) Received: from bj03382pcu.spreadtrum.com ([117.18.48.82]) by smtp.gmail.com with ESMTPSA id v14sm14165972pfm.164.2019.08.18.22.50.14 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sun, 18 Aug 2019 22:50:18 -0700 (PDT) From: Zhaoyang Huang To: Andrew Morton , Zhaoyang Huang , Russell King , Mike Rapoport , Rob Herring , Florian Fainelli , Geert Uytterhoeven , Doug Berger , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] arch : arm : add a criteria for pfn_valid Date: Mon, 19 Aug 2019 13:50:08 +0800 Message-Id: <1566193808-9153-1-git-send-email-huangzhaoyang@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1566179120-5910-1-git-send-email-huangzhaoyang@gmail.com> References: <1566179120-5910-1-git-send-email-huangzhaoyang@gmail.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Zhaoyang Huang pfn_valid can be wrong when parsing a invalid pfn whose phys address exceeds BITS_PER_LONG as the MSB will be trimed when shifted. The issue originally arise from bellowing call stack, which corresponding to an access of the /proc/kpageflags from userspace with a invalid pfn parameter and leads to kernel panic. [46886.723249] c7 [] (stable_page_flags) from [] [46886.723264] c7 [] (kpageflags_read) from [] [46886.723280] c7 [] (proc_reg_read) from [] [46886.723290] c7 [] (__vfs_read) from [] [46886.723301] c7 [] (vfs_read) from [] [46886.723315] c7 [] (SyS_pread64) from [] (ret_fast_syscall+0x0/0x28) Signed-off-by: Zhaoyang Huang --- v2: use __pfn_to_phys/__phys_to_pfn instead of max_pfn as the criteria v3: update commit message to describe the defection's context --- arch/arm/mm/init.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index c2daabb..cc769fa 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -177,6 +177,11 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max_low, #ifdef CONFIG_HAVE_ARCH_PFN_VALID int pfn_valid(unsigned long pfn) { + phys_addr_t addr = __pfn_to_phys(pfn); + + if (__phys_to_pfn(addr) != pfn) + return 0; + return memblock_is_map_memory(__pfn_to_phys(pfn)); } EXPORT_SYMBOL(pfn_valid); -- 1.9.1