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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 982BEC2BBCA for ; Thu, 10 Dec 2020 13:38:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6636622D06 for ; Thu, 10 Dec 2020 13:38:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389560AbgLJNiD (ORCPT ); Thu, 10 Dec 2020 08:38:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389450AbgLJNfi (ORCPT ); Thu, 10 Dec 2020 08:35:38 -0500 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4008C061794 for ; Thu, 10 Dec 2020 05:34:57 -0800 (PST) Received: by mail-pl1-x641.google.com with SMTP id 4so2774945plk.5 for ; Thu, 10 Dec 2020 05:34:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=jRaoY3l4sn+gFv9tuxtAOcZu8uN2SZx2b/9rieqqeRk=; b=kxK5Ei7ZoihlUR+znIRWS5gS68sI/ms87hjk369Wk5IIp4rlMUCARiQEeMci/vu/sb jkFQUxRS9QibsFzo02Y4phhKBI+xMI6wJYSzeIv0xs3lIjysPEIUbb19fZYfLr2rGsvi /h1kQmkXVcyJpk2sMeUPVqZWrEjP0puRrYniLKjsDN1dQINNCqjrTdrs2Mpa/jsPwbZB Ze9Jw0MXMPL5m6zEeJDF+osoypgc7w3LRs/a6nweJ1Eh6BQS0iMIUSrTchuDKysKBEL9 1s6RHAu6d3iHRlPjmmQADRp73kKjA0qDzeba+1tZMCfTxVQUsSpQ5nVhVjP6iq09jvPg E5ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=jRaoY3l4sn+gFv9tuxtAOcZu8uN2SZx2b/9rieqqeRk=; b=WO140AnQAp/E43HdW91sHwwLXWxnvKQJitxDD/OgH5fUCGVMFk69hNcKbwZN7BbTNg /iE5nuego9CM6Bhq3ABfyTitYp5rCrF8Bgyx7fcQzkb1DCT2xWQrZ4I71XPcckKhVDd2 hHIJJGwL5Lxh3ydW5jVH5hx1E2h96ZYKygjvjWPFGyNQu0OClNVfqnC58FQ9uaHOaDfq be/AyY8sjGBWjOvXEYykmFuaP/w/7tBgZm14X3yu6Zwg33hblbjQL4YIEGLf8MTiWZmj TrvZXL4LRGHVtYBcRBJwJDC1qwB/ie7wDAjZMWZitKoUyNiuEc1Y8FlTrSyPIzwWI295 y0lQ== X-Gm-Message-State: AOAM531iNACy2CLIoj9Z+X9E2UcPvCK2EJyXgMT7RFYdxdirtJSOI2jP jih2fwu1nY11ToAi7jSnl//kGdIvq2s= X-Google-Smtp-Source: ABdhPJy2PZEUhVgeSuRpUGxFnar5kYmJVU65LKjHW7e+FFsNf72uag1hkV5WHs4G3jVuUndUB65Ghg== X-Received: by 2002:a17:902:a70a:b029:da:1911:4285 with SMTP id w10-20020a170902a70ab02900da19114285mr6690357plq.44.1607607297175; Thu, 10 Dec 2020 05:34:57 -0800 (PST) Received: from localhost ([47.251.4.198]) by smtp.gmail.com with ESMTPSA id v125sm3810048pgv.6.2020.12.10.05.34.56 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 10 Dec 2020 05:34:56 -0800 (PST) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: Lai Jiangshan , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" Subject: [PATCH V2 2/3] x86/mm/pti: issue warning when mapping large pmd beyond specifid range Date: Thu, 10 Dec 2020 22:35:25 +0800 Message-Id: <20201210143527.2398-2-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20201210143527.2398-1-jiangshanlai@gmail.com> References: <0766416e-bab5-c8e7-9466-a72e965fdb8a@intel.com> <20201210143527.2398-1-jiangshanlai@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lai Jiangshan When PTI_CLONE_PTE, the caller doesn't want to expose pages beyond specifid range and it worths a warning. Signed-off-by: Lai Jiangshan --- arch/x86/mm/pti.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 7ee99ef13a99..cd6da1d42ba9 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -356,6 +356,13 @@ pti_clone_pgtable(unsigned long start, unsigned long end, * caller, so we just simply align it here. */ addr = round_down(addr, PMD_SIZE); + /* + * Mapping large pmd beyond [start, end) may expose + * secrets to user-space when it wants to clone ptes + * only. + */ + WARN_ON_ONCE(level == PTI_CLONE_PTE && + (addr < start || end < addr + PMD_SIZE)); target_pmd = pti_user_pagetable_walk_pmd(addr); if (WARN_ON(!target_pmd)) -- 2.19.1.6.gb485710b