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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 0F887C282C7 for ; Tue, 29 Jan 2019 08:09:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D242B214DA for ; Tue, 29 Jan 2019 08:09:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Yfe/lYWx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727877AbfA2IJr (ORCPT ); Tue, 29 Jan 2019 03:09:47 -0500 Received: from mail-vk1-f193.google.com ([209.85.221.193]:43432 "EHLO mail-vk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727781AbfA2IJp (ORCPT ); Tue, 29 Jan 2019 03:09:45 -0500 Received: by mail-vk1-f193.google.com with SMTP id o130so4297836vke.10 for ; Tue, 29 Jan 2019 00:09:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HskzooTvMqAmijkoLembaa8q/EUEh+gg5JDbqI0lirU=; b=Yfe/lYWx+W08Wnk0LT/9pDOe33v6r/YJCX5FHNL8f7PXRPgQ1pULitx5UhzCxQozax sUmP0OKPSRBgz5/GAzgXWKinyALuD6Rusi8YhMCk2/sHGw9Yt1IqU4RuXsexPaHqYRN2 vnrz1YDb7OGnn7mAzynSfkfNPRgP+5JqFpt78= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=HskzooTvMqAmijkoLembaa8q/EUEh+gg5JDbqI0lirU=; b=XQSUTrhdI+sIFGzO+IIbFmnlq/VN+xy3gyhBJuCEvFKHezvMpBHnhEdYVLTWPVhDfd GgGRP6/ls2qeG+P9E4gxMm7CaQARO7g/0SWaCHpmUIcz30h2mgHCeAjHtWamd8unzD6Z 0qaGRfyKVKlkaOsq3eNkk6yPkVNktvC0DWNn04Kd3AG3SCq+RpHOr7GUHPb4VS7ZOBsi tbbDr/Dz72PxnVPpwzJyH5XjZlNxrvOTy24WM8Z7ofE3yvWMh7cvQkx6VVG9wR+vo8cc PBP3FMhTNu84yqX9rRz2PZDr0tv6ZxontCMh1678Q8cArGtgv3pC5N+bz3GefemKcoc8 cdWQ== X-Gm-Message-State: AJcUukdIhYcFmKV42z4BAqHt9ytqxSvcKFU/xfYiSunKW6X4HcIsmaVn dyz8wMv7Uc4qBcxd6Z8loe5zuUY3w0Q= X-Google-Smtp-Source: ALg8bN54y+/gtDSIAt/eUv88cmJNOgC9i7LkSX0tHIJwH6K2VeLR2TiJQAD+Kef1nhkflGiU2kGOtg== X-Received: by 2002:a1f:7cca:: with SMTP id x193mr10446305vkc.89.1548749383887; Tue, 29 Jan 2019 00:09:43 -0800 (PST) Received: from mail-ua1-f46.google.com (mail-ua1-f46.google.com. [209.85.222.46]) by smtp.gmail.com with ESMTPSA id w140sm24649478vkw.2.2019.01.29.00.09.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 29 Jan 2019 00:09:42 -0800 (PST) Received: by mail-ua1-f46.google.com with SMTP id e16so6522641uam.12 for ; Tue, 29 Jan 2019 00:09:42 -0800 (PST) X-Received: by 2002:ab0:470d:: with SMTP id h13mr10723029uac.122.1548749382268; Tue, 29 Jan 2019 00:09:42 -0800 (PST) MIME-Version: 1.0 References: <20190129053830.3749-1-willy@infradead.org> In-Reply-To: <20190129053830.3749-1-willy@infradead.org> From: Kees Cook Date: Tue, 29 Jan 2019 21:09:30 +1300 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] mm: Prevent mapping typed pages to userspace To: Matthew Wilcox Cc: Andrew Morton , Linux-MM , LKML , Kernel Hardening , Michael Ellerman , Will Deacon Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 29, 2019 at 6:38 PM Matthew Wilcox wrote: > > Pages which use page_type must never be mapped to userspace as it would > destroy their page type. Add an explicit check for this instead of > assuming that kernel drivers always get this right. > > Signed-off-by: Matthew Wilcox Reviewed-by: Kees Cook -Kees > --- > mm/memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memory.c b/mm/memory.c > index ce8c90b752be..db3534bbd652 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1451,7 +1451,7 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr, > spinlock_t *ptl; > > retval = -EINVAL; > - if (PageAnon(page) || PageSlab(page)) > + if (PageAnon(page) || PageSlab(page) || page_has_type(page)) > goto out; > retval = -ENOMEM; > flush_dcache_page(page); > -- > 2.20.1 > -- Kees Cook 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=-7.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 5DC96C4151A for ; Tue, 29 Jan 2019 08:09:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1585E217F5 for ; Tue, 29 Jan 2019 08:09:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Yfe/lYWx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1585E217F5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 89B048E0002; Tue, 29 Jan 2019 03:09:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 84B138E0001; Tue, 29 Jan 2019 03:09:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7137E8E0002; Tue, 29 Jan 2019 03:09:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-vs1-f71.google.com (mail-vs1-f71.google.com [209.85.217.71]) by kanga.kvack.org (Postfix) with ESMTP id 3966C8E0001 for ; Tue, 29 Jan 2019 03:09:45 -0500 (EST) Received: by mail-vs1-f71.google.com with SMTP id g5so962969vsi.2 for ; Tue, 29 Jan 2019 00:09:45 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:mime-version:references :in-reply-to:from:date:message-id:subject:to:cc; bh=HskzooTvMqAmijkoLembaa8q/EUEh+gg5JDbqI0lirU=; b=IpCPuYcCxU7G6MLZ+5hyvIiQmJ5z2dwqZgJhCMPF5Mm8ShwjMEOvMZDnxE5wLmNDHs LQUWDYa75k00J02N4nuhN2maH1agcsIxcZi1YYSlSUyCJJfwF4mex+sZ36Ejuh8qh1Vg IZnXUQ44Py8+dworejzLA+BUYfDSVQghPwKF4toLXtgGeOUxMs2ffEHFjQl95uZbwduy QKewCG2cAQxDqy2ybDb1ggL5lpYqIoHQHgh18SfhkN3bHG++9ZAAacT3HA3iGuCUTdBI U+unuT4T7XJIoMCqzpj5OuBR+qvl23+DLfDTOPoq8ZwurlIrqTUqEm1GBNnPI1iwyfWi XbZQ== X-Gm-Message-State: AJcUukcWXnoce7OXj3WscnpCF8grlYo2r2RAKRLkJ8ck8e3yGxhVfhCO cvzsBW5ZJNRg4Rp9jiTKTuyeQUd61clTi5aIcQtspjEsbh/8/RDaa0vgLSTQJKOsPxXT6kcG+sZ lAqVWYM7lQOJ8TphzC0irV/DIGxAytADsAianakcumLOavFIK5QM7j8s7O5/Hvx2JidKc2Dn2S1 qSpIGecCzRsWT6ZL5MeDJDeU4r7oJnSFVytHHVoAmBXixeD8MoFhtIDX/RQWxijoFF13L4ESiK2 o34mjwt5gZoN61GfTWgqiQMzJKRUeF3vjCd7GOHj/OlbknWyzxvMXCyEe300jbG7Kzt5HcMM2S+ XHnQUsVCOMlkRbFnxH4cpoPEob4TtrW2T9aRTJwt0luaPaEx6X6QC6p0yW/SBm8+A4/QF9xd36m 6 X-Received: by 2002:a67:edd8:: with SMTP id e24mr10986676vsp.169.1548749384853; Tue, 29 Jan 2019 00:09:44 -0800 (PST) X-Received: by 2002:a67:edd8:: with SMTP id e24mr10986658vsp.169.1548749384357; Tue, 29 Jan 2019 00:09:44 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1548749384; cv=none; d=google.com; s=arc-20160816; b=K2jNoH8TOwnTyyzvobhtqP9OiJ7o8CKDpYSbSbEihwztmhXOOlGFQ+TMpleHyXP6XS wQF6VwB5S2YqlFuznbRv4SxE0bJ5ga9nkB809DsM3SSqywV/gZW2FB6unh81uUZD71mB QzvMzGPwDyKw0tMN8niR9YftztU+NcPtKbY6sH3OgkQQI8Cki2n73BsaJP36T7ZXO3v3 I6y/xq8apjBa8SR0tOnOeXiGiaWX/PBASa0Q6ok6FLIuJlpMQi6Z9cnTrNIbfcvYv5VA PINfwNmNAxvXXpxFB9mMF31HHgK3gns0H+yRSpVaIvcw1r70yCos2JuABhJ0wAOcmJtD /OGQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:dkim-signature; bh=HskzooTvMqAmijkoLembaa8q/EUEh+gg5JDbqI0lirU=; b=Db8j/jrtWkibixkgMGvDItRALCnqP5d36gAfk3lOewp4bTf3f7WbfVTQyBDSkSNg+f GYGHjSg/6vgXjt+XgdcdTzzzlqjv0yEF0XfIXnd6LwdMKDQFs6nt5CmUwniJnB9YhDSL vYkABbskYhktMN5JyXGr2DiCvBSokVALUjlwsD1cCAfK/hAlnUWFTsw1Y9yLTNHt02Vz gYYGrNp5ZRAgnX4VsRr0C5LdtaHdF3D331n0/AwP3dgmDc/L+iiZPhtKEIMjBAbTr6TI Rj+HiszST3IwTHqX+R6OEYR3mwEllDb4yzveY6S2BC9ICsrRy6lzvQnlS7ViCxGcebTd hhRQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b="Yfe/lYWx"; spf=pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id h75sor22625982vsg.0.2019.01.29.00.09.44 for (Google Transport Security); Tue, 29 Jan 2019 00:09:44 -0800 (PST) Received-SPF: pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b="Yfe/lYWx"; spf=pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HskzooTvMqAmijkoLembaa8q/EUEh+gg5JDbqI0lirU=; b=Yfe/lYWx+W08Wnk0LT/9pDOe33v6r/YJCX5FHNL8f7PXRPgQ1pULitx5UhzCxQozax sUmP0OKPSRBgz5/GAzgXWKinyALuD6Rusi8YhMCk2/sHGw9Yt1IqU4RuXsexPaHqYRN2 vnrz1YDb7OGnn7mAzynSfkfNPRgP+5JqFpt78= X-Google-Smtp-Source: ALg8bN7sVVE7ciRiR4XoigIHgE0fU2mMLar/zkbfwI4s6K2j4QCRS3h1Z5YKgKbfeV1pRchIgv93+A== X-Received: by 2002:a67:334a:: with SMTP id z71mr10800052vsz.40.1548749383751; Tue, 29 Jan 2019 00:09:43 -0800 (PST) Received: from mail-ua1-f46.google.com (mail-ua1-f46.google.com. [209.85.222.46]) by smtp.gmail.com with ESMTPSA id y195sm72854468vkd.0.2019.01.29.00.09.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 29 Jan 2019 00:09:42 -0800 (PST) Received: by mail-ua1-f46.google.com with SMTP id c12so6545087uas.6 for ; Tue, 29 Jan 2019 00:09:42 -0800 (PST) X-Received: by 2002:ab0:470d:: with SMTP id h13mr10723029uac.122.1548749382268; Tue, 29 Jan 2019 00:09:42 -0800 (PST) MIME-Version: 1.0 References: <20190129053830.3749-1-willy@infradead.org> In-Reply-To: <20190129053830.3749-1-willy@infradead.org> From: Kees Cook Date: Tue, 29 Jan 2019 21:09:30 +1300 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] mm: Prevent mapping typed pages to userspace To: Matthew Wilcox Cc: Andrew Morton , Linux-MM , LKML , Kernel Hardening , Michael Ellerman , Will Deacon Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jan 29, 2019 at 6:38 PM Matthew Wilcox wrote: > > Pages which use page_type must never be mapped to userspace as it would > destroy their page type. Add an explicit check for this instead of > assuming that kernel drivers always get this right. > > Signed-off-by: Matthew Wilcox Reviewed-by: Kees Cook -Kees > --- > mm/memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memory.c b/mm/memory.c > index ce8c90b752be..db3534bbd652 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1451,7 +1451,7 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr, > spinlock_t *ptl; > > retval = -EINVAL; > - if (PageAnon(page) || PageSlab(page)) > + if (PageAnon(page) || PageSlab(page) || page_has_type(page)) > goto out; > retval = -ENOMEM; > flush_dcache_page(page); > -- > 2.20.1 > -- Kees Cook