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=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 42EC1C3A59B for ; Mon, 19 Aug 2019 05:50:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1436020851 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" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726594AbfHSFuU (ORCPT ); Mon, 19 Aug 2019 01:50:20 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:41580 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725846AbfHSFuT (ORCPT ); Mon, 19 Aug 2019 01:50:19 -0400 Received: by mail-pl1-f193.google.com with SMTP id m9so421789pls.8 for ; Sun, 18 Aug 2019 22:50:19 -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=dJKGLdF+8XEbUuiMzKotm4pGQooLMHoJCqyBJPBs5fA6R3JRKj3kDWfXIgkXwA/ZuU u1nESlc45mu/tyyMBqj8zAaw6pPq3NjKGNRFyjA/09fMShgHpv+sPZRp8WJ60A6nGZtd Vkocac0mP4EX1hpP+eekzVBr0b5TY8ErUHZ+9KVcU391Q2+8LB73KnSRiJdF9hah8BFn GnFZx2bM8DzbHK7gtCzr8xJtVNGPXoPoFRJfvomlnefWK8K0VrsfNrkpdLpTkwAbAvKr i2ISVjLKHfRdmeRwKh/j8/jaXwelHfzNb36mQ2AA0oRHaSY/IjcpbzKtf0pApsVmQZeh 9s9A== X-Gm-Message-State: APjAAAW7PItWm12eSPEXSAfcT/8n9l5QnCsh/REjZ2khZiRJHKkHvcMY wR5KCQikYGzAufjsRRqlJ/Q= 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> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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