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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA1C6C433F5 for ; Thu, 20 Jan 2022 19:05:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0DA416B0082; Thu, 20 Jan 2022 14:05:06 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 08A156B0083; Thu, 20 Jan 2022 14:05:06 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E93296B0085; Thu, 20 Jan 2022 14:05:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0148.hostedemail.com [216.40.44.148]) by kanga.kvack.org (Postfix) with ESMTP id DB4596B0082 for ; Thu, 20 Jan 2022 14:05:05 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 9F73B8249980 for ; Thu, 20 Jan 2022 19:05:05 +0000 (UTC) X-FDA: 79051592970.24.BDC0A32 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf28.hostedemail.com (Postfix) with ESMTP id 15401C0109 for ; Thu, 20 Jan 2022 19:04:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=jA3CkCc0pg/2NQ16pdnmk4INkOngIqZyjRj6CQv0y+c=; b=mWrA67bmZ0wgwVuAnDToH7NT5L tpqZLXGiB06qrUdIo/Eh+0EBZy1NY/6RkcOWEE2CSGzDZeta6FEVqX3aFaR/K/cgEzkCURbyCD9j1 4kB5POQ3MscqS9I+15ByHaaZJrQQdTFwqoQArQr4C9zMoQ91/ydTCGyTuKibrGb7F1w2c+uKMxm8A cYMDAg13wAtDIWELgkBXA8gRB6lnvzC16bBEnhLcr1VCeMQ1d+zEsIuHLbk+K6pxftU2oXYyouM0o LjGakAXEFB6UBVZREtLN9c5XnlCUcA/KAbZGEadfng+aImnIlZUPZncJn2zA9jsFEBpk9s5mgUJXu Ar4ls3yw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nAcjS-00EcJJ-4B; Thu, 20 Jan 2022 19:04:26 +0000 Date: Thu, 20 Jan 2022 19:04:26 +0000 From: Matthew Wilcox To: "Russell King (Oracle)" Cc: Robin Murphy , Yury Norov , Catalin Marinas , Will Deacon , Andrew Morton , Nicholas Piggin , Ding Tianhong , Anshuman Khandual , Alexey Klimov , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] vmap(): don't allow invalid pages Message-ID: References: <20220118235244.540103-1-yury.norov@gmail.com> <319b09bc-56a2-207f-6180-3cc7d8cd43d1@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 15401C0109 X-Stat-Signature: yraamjsdjk4x7ecjb4chnpsjz5aoepwh Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=mWrA67bm; dmarc=none; spf=none (imf28.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Rspamd-Server: rspam08 X-HE-Tag: 1642705490-915301 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 Thu, Jan 20, 2022 at 04:54:03PM +0000, Russell King (Oracle) wrote: > Well, I think I've adequately explained why I believe: > > pfn_is_valid(page_to_pfn(page)) > > being used as the primary check is substandard, and will likely lead to > a future CVE. When generating an array of struct page's, I believe that > it is the responsibility for the generator to ensure that the array > only contains valid pages. So you're saying that virt_to_page() should be made more expensive?