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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 EEF6AC3A5A6 for ; Thu, 19 Sep 2019 22:34:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B088D21BE5 for ; Thu, 19 Sep 2019 22:34:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568932475; bh=AXPR9OXJuhp5iAZ5tC1XbkvuhWf5TaT1co01bJ2eGsE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2qJQLjdT92YxxWt0Zpzh/uMXKwS6+r+2SN3M7aSTkUdWXaLRT9Q3FFveJkV+80RmT lILWtgTbF6OUYLEFSPJbpkh0X/0V2UF7Am2ighCQH2H3WaBajVdzmKJKuFq4xmqMWM ORMNvkZaNZfgb8ocGx+ei3js09D2CFVOPE7g4W68= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405081AbfISWef (ORCPT ); Thu, 19 Sep 2019 18:34:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:47886 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405462AbfISWJi (ORCPT ); Thu, 19 Sep 2019 18:09:38 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1D0DC21907; Thu, 19 Sep 2019 22:09:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568930977; bh=AXPR9OXJuhp5iAZ5tC1XbkvuhWf5TaT1co01bJ2eGsE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CF27y1I214x9qjCtnPqqai8qV6AUeP1YCBQ3sMQjoUdjAAl+I4hoxb2fnwdSkjP18 2E7ZiBJYjQuJwf4fZqnC/JExkN7G4IFX5bbdTK9CHJGbl1ty6gRPkdEWJhblbTLh4e U6nA6LpR1iXybjBWhBr7ts4PoGubZpkh2/8D+5ZU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhaoyang Huang , Russell King , Sasha Levin Subject: [PATCH 5.2 084/124] ARM: 8901/1: add a criteria for pfn_valid of arm Date: Fri, 20 Sep 2019 00:02:52 +0200 Message-Id: <20190919214822.077733327@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190919214819.198419517@linuxfoundation.org> References: <20190919214819.198419517@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: zhaoyang [ Upstream commit 5b3efa4f1479c91cb8361acef55f9c6662feba57 ] 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 Signed-off-by: Russell King Signed-off-by: Sasha Levin --- 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 8e793cddac661..98e17388a563f 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -174,6 +174,11 @@ 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); -- 2.20.1