From patchwork Fri Jun 5 14:15:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 224804 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,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 E0999C433E1 for ; Fri, 5 Jun 2020 14:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B790820835 for ; Fri, 5 Jun 2020 14:17:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591366636; bh=3Vm5TjOSQhMNc3SNvzYPdmBcWA0iDVpz8xDLk1V4c00=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XKp4DOV0A1c8a1EjZCJarjS4x4p9M98QbCRvqfS/2P2oLu3KHO9F8OmyEqe8LyDHr mkpt5/yAnHGb0At6/4/BsAnS3di2Vix6zgBjv+bTkxOC2Xe1fTDVijbQlXbJako5zX 1aTLoLJJHlAXwNjHbZORS46idXqvcLa6l/ZHzyg0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728421AbgFEORP (ORCPT ); Fri, 5 Jun 2020 10:17:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:46568 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728414AbgFEORN (ORCPT ); Fri, 5 Jun 2020 10:17:13 -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 68A3A206A2; Fri, 5 Jun 2020 14:17:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591366632; bh=3Vm5TjOSQhMNc3SNvzYPdmBcWA0iDVpz8xDLk1V4c00=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iMnVBKcqJXPHuJmy984J+Da/V0ZHO9N98UI6xPtop2DZvyoBAxyOXAMF1KEt92P8G puEun4euMBXqsNHg9ibUu6bA1RtnaeB3vRjlkkC3+7rfCjjI/tEXx7JnjQ8xnpWCBY bPqeSUMWjs42AA24t7bghgTWsUk/Ge38Q+ZOuWO4= 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 5.6 31/43] mm: Fix mremap not considering huge pmd devmap Date: Fri, 5 Jun 2020 16:15:01 +0200 Message-Id: <20200605140154.154168800@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200605140152.493743366@linuxfoundation.org> References: <20200605140152.493743366@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -256,6 +256,7 @@ 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() */