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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 6F0A4C2BA83 for ; Fri, 14 Feb 2020 17:55:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41D532168B for ; Fri, 14 Feb 2020 17:55:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581702930; bh=11ds414/iVeTj4WTOhRtPXdUUxm9wT7k1cnNpmj1euk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bMT25SoSVmYH+EKwkL4J6VT/5ZLKEOeTF/YfbvIJqxedkhkvXXiGkJpNw4ZnTpRay U0dlaIYoR3lK+jPAelrWFhKFbJr9OK+9eUveqklF0tJ3Xm9DSQ2CyCibxqV1C0ANJY 75SskijSPqDh35b8K8SdXs9FxIO4ZEb7FrzI8PuA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387682AbgBNRz0 (ORCPT ); Fri, 14 Feb 2020 12:55:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:41062 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387916AbgBNP5o (ORCPT ); Fri, 14 Feb 2020 10:57:44 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 18B902082F; Fri, 14 Feb 2020 15:57:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581695863; bh=11ds414/iVeTj4WTOhRtPXdUUxm9wT7k1cnNpmj1euk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wQlnLKv7DQfdjq+IxqxNy43OZshfYusGBniwW/8PW+TuvC5UpVLIJNn+0uZM/u/ly av8WH7mjSNOvEIItQxVjTRzhtvRxsRuZPqFzjfgQUjXKCGIRU2Ad1+r8sCswGlu+6Q Wlgmyl1OCFEo3MEzyN3hREVW4w9EGLJ6CfXi3lV4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ard Biesheuvel , Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 5.5 410/542] x86/mm: Fix NX bit clearing issue in kernel_map_pages_in_pgd Date: Fri, 14 Feb 2020 10:46:42 -0500 Message-Id: <20200214154854.6746-410-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214154854.6746-1-sashal@kernel.org> References: <20200214154854.6746-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ard Biesheuvel [ Upstream commit 75fbef0a8b6b4bb19b9a91b5214f846c2dc5139e ] The following commit: 15f003d20782 ("x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd()") modified kernel_map_pages_in_pgd() to manage writable permissions of memory mappings in the EFI page table in a different way, but in the process, it removed the ability to clear NX attributes from read-only mappings, by clobbering the clear mask if _PAGE_RW is not being requested. Failure to remove the NX attribute from read-only mappings is unlikely to be a security issue, but it does prevent us from tightening the permissions in the EFI page tables going forward, so let's fix it now. Fixes: 15f003d20782 ("x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd() Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200113172245.27925-5-ardb@kernel.org Signed-off-by: Sasha Levin --- arch/x86/mm/pageattr.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 1b99ad05b1177..f42780ba08937 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -2215,7 +2215,7 @@ int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, .pgd = pgd, .numpages = numpages, .mask_set = __pgprot(0), - .mask_clr = __pgprot(0), + .mask_clr = __pgprot(~page_flags & (_PAGE_NX|_PAGE_RW)), .flags = 0, }; @@ -2224,12 +2224,6 @@ int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, if (!(__supported_pte_mask & _PAGE_NX)) goto out; - if (!(page_flags & _PAGE_NX)) - cpa.mask_clr = __pgprot(_PAGE_NX); - - if (!(page_flags & _PAGE_RW)) - cpa.mask_clr = __pgprot(_PAGE_RW); - if (!(page_flags & _PAGE_ENC)) cpa.mask_clr = pgprot_encrypted(cpa.mask_clr); -- 2.20.1