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,URIBL_BLOCKED,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 8C28CC2D0EC for ; Fri, 10 Apr 2020 03:47:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 64CEA20CC7 for ; Fri, 10 Apr 2020 03:47:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490433; bh=iFWKPM79D+eOwWhbxjk4po4LTD20a1ZJmbOg1VrHgQg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wlnhalAMvu9g0qVa3BLnDxIJDydGQHLaJVtfpunvWsdRGeNML9U7PFTIQ+xztrVKi 8cWpP9an6o7YkDgL5Fpli4bPistz+NbiGctVJdTfOaNGDpq37nGpNXIy7lNw+HIruc t1M6Z2Fr2Mt39eSNK2o3dAEVMWPCgWhcdhdLfRCI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727072AbgDJDrL (ORCPT ); Thu, 9 Apr 2020 23:47:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:57602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727026AbgDJDrJ (ORCPT ); Thu, 9 Apr 2020 23:47:09 -0400 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 460B720CC7; Fri, 10 Apr 2020 03:47:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490429; bh=iFWKPM79D+eOwWhbxjk4po4LTD20a1ZJmbOg1VrHgQg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=juLTdPHULmQ4nlvg4Wi5gTT4lK5aTWmXKIkZILb8iZ30j8eaQBM7wQwGzsxq+mSoQ qsqWsMNyz8puEhaeskBtJwpceesF7iOrG0SKH1OCioN/J64InXl270JzTFRncbUaM8 ICSsrNLNzqChfrPtJE2MuK3UVHQ1tMnp+Tq1ryZ4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thomas Hellstrom , Borislav Petkov , Dave Hansen , Tom Lendacky , Sasha Levin Subject: [PATCH AUTOSEL 5.6 27/68] x86: Don't let pgprot_modify() change the page encryption bit Date: Thu, 9 Apr 2020 23:45:52 -0400 Message-Id: <20200410034634.7731-27-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200410034634.7731-1-sashal@kernel.org> References: <20200410034634.7731-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Hellstrom [ Upstream commit 6db73f17c5f155dbcfd5e48e621c706270b84df0 ] When SEV or SME is enabled and active, vm_get_page_prot() typically returns with the encryption bit set. This means that users of pgprot_modify(, vm_get_page_prot()) (mprotect_fixup(), do_mmap()) end up with a value of vma->vm_pg_prot that is not consistent with the intended protection of the PTEs. This is also important for fault handlers that rely on the VMA vm_page_prot to set the page protection. Fix this by not allowing pgprot_modify() to change the encryption bit, similar to how it's done for PAT bits. Signed-off-by: Thomas Hellstrom Signed-off-by: Borislav Petkov Reviewed-by: Dave Hansen Acked-by: Tom Lendacky Link: https://lkml.kernel.org/r/20200304114527.3636-2-thomas_os@shipmail.org Signed-off-by: Sasha Levin --- arch/x86/include/asm/pgtable.h | 7 +++++-- arch/x86/include/asm/pgtable_types.h | 2 +- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 7e118660bbd98..64a03f226ab73 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -627,12 +627,15 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) return __pmd(val); } -/* mprotect needs to preserve PAT bits when updating vm_page_prot */ +/* + * mprotect needs to preserve PAT and encryption bits when updating + * vm_page_prot + */ #define pgprot_modify pgprot_modify static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) { pgprotval_t preservebits = pgprot_val(oldprot) & _PAGE_CHG_MASK; - pgprotval_t addbits = pgprot_val(newprot); + pgprotval_t addbits = pgprot_val(newprot) & ~_PAGE_CHG_MASK; return __pgprot(preservebits | addbits); } diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 0239998d8cdc0..65c2ecd730c5b 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -118,7 +118,7 @@ */ #define _PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \ _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY | \ - _PAGE_SOFT_DIRTY | _PAGE_DEVMAP) + _PAGE_SOFT_DIRTY | _PAGE_DEVMAP | _PAGE_ENC) #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE) /* -- 2.20.1