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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 263EEC433DF for ; Fri, 5 Jun 2020 14:18:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8371208FE for ; Fri, 5 Jun 2020 14:18:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591366710; bh=9bgOnoqQ3+XkHBwKqZjrpgx+J9Wfv4rHG89fs41V1TM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XmeD78+KQnRqTFGNG2TqMShUEEvT9HCf2pON7/bd9ybiEsV1a0tio+F7nmMc8aQiZ 5dk671HmG40kbtMPgW1lW20xmMGbo5ghR8aXcGm9QZcWF/hszHizhY1lcW5dEhmKwJ ykFCSLeTftU9wsMgMKe1h++Xjw4pw9MSBKU6i9ew= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728313AbgFEOS2 (ORCPT ); Fri, 5 Jun 2020 10:18:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:48910 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728661AbgFEOSX (ORCPT ); Fri, 5 Jun 2020 10:18:23 -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 D84D5208B8; Fri, 5 Jun 2020 14:18:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591366703; bh=9bgOnoqQ3+XkHBwKqZjrpgx+J9Wfv4rHG89fs41V1TM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bCbKh1rVRdcruYOjlT37m4Byq/recCkv5f1fdGBrj4eTqiiiTkZF8KuAiLt88RJ0Q SqdKcM8h85CmDxeq+60nPPPnSdl/Cx5okjgSz63NzU9GjJ1mzrhIL42akifRzd+OiQ KCrtYtwi3//jdWjuEUjcU7YlIDxBAVerv3KGDmwU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fan Yang , Dan Williams , "Kirill A. Shutemov" , Linus Torvalds Subject: [PATCH 5.4 02/38] mm: Fix mremap not considering huge pmd devmap Date: Fri, 5 Jun 2020 16:14:45 +0200 Message-Id: <20200605140252.678256519@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200605140252.542768750@linuxfoundation.org> References: <20200605140252.542768750@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: Fan Yang commit 5bfea2d9b17f1034a68147a8b03b9789af5700f9 upstream. The original code in mm/mremap.c checks huge pmd by: if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd)) { However, a DAX mapped nvdimm is mapped as huge page (by default) but it is not transparent huge page (_PAGE_PSE | PAGE_DEVMAP). This commit changes the condition to include the case. This addresses CVE-2020-10757. Fixes: 5c7fb56e5e3f ("mm, dax: dax-pmd vs thp-pmd vs hugetlbfs-pmd") Cc: Reported-by: Fan Yang Signed-off-by: Fan Yang Tested-by: Fan Yang Tested-by: Dan Williams Reviewed-by: Dan Williams Acked-by: Kirill A. Shutemov Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/pgtable.h | 1 + mm/mremap.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -253,6 +253,7 @@ static inline int pmd_large(pmd_t pte) } #ifdef CONFIG_TRANSPARENT_HUGEPAGE +/* NOTE: when predicate huge page, consider also pmd_devmap, or use pmd_large */ static inline int pmd_trans_huge(pmd_t pmd) { return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE; --- a/mm/mremap.c +++ b/mm/mremap.c @@ -266,7 +266,7 @@ unsigned long move_page_tables(struct vm new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr); if (!new_pmd) break; - if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd)) { + if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd) || pmd_devmap(*old_pmd)) { if (extent == HPAGE_PMD_SIZE) { bool moved; /* See comment in move_ptes() */