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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=no 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 534C9C64E90 for ; Mon, 23 Nov 2020 20:11:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1C6B20715 for ; Mon, 23 Nov 2020 20:11:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="s0Z9tEU4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732610AbgKWULN (ORCPT ); Mon, 23 Nov 2020 15:11:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:37032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732570AbgKWULL (ORCPT ); Mon, 23 Nov 2020 15:11:11 -0500 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E87FB20715; Mon, 23 Nov 2020 20:11:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1606162270; bh=S16KBwhaL/01tGXV0yjo+fhZ/1ZXyYm+GDtWWM3lQiw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=s0Z9tEU4SklazDQUZnIX5EresDQad7SkzVV2bA8lAe3AE+57E0+xaXNcttXDY4c3N 2DLWeaq2KtP2uKBIu+v5SmBGjWPsJqeNodCJ3t2iSZYrAGR5dAAy9wYfOqec5z79Bc gQMMbWP6RmrFDEd8+nDIcp2R2ji6h62jIynqVV8A= Date: Mon, 23 Nov 2020 12:11:08 -0800 From: Andrew Morton To: Lokesh Gidra Cc: Kees Cook , Jonathan Corbet , Peter Xu , Andrea Arcangeli , Sebastian Andrzej Siewior , Alexander Viro , Stephen Smalley , Eric Biggers , Daniel Colascione , "Joel Fernandes (Google)" , Linux FS Devel , linux-kernel , linux-doc@vger.kernel.org, Kalesh Singh , Calin Juravle , Suren Baghdasaryan , Jeffrey Vander Stoep , "Cc: Android Kernel" , Mike Rapoport , Shaohua Li , Jerome Glisse , Mauro Carvalho Chehab , Johannes Weiner , Mel Gorman , Nitin Gupta , Vlastimil Babka , Iurii Zaikin , Luis Chamberlain , linux-mm@kvack.kernel.org, Daniel Colascione , "open list:MEMORY MANAGEMENT" Subject: Re: [PATCH v6 1/2] Add UFFD_USER_MODE_ONLY Message-Id: <20201123121108.24d178769cfc9500c7c51317@linux-foundation.org> In-Reply-To: References: <20201120030411.2690816-1-lokeshgidra@google.com> <20201120030411.2690816-2-lokeshgidra@google.com> <20201120153337.431dc36c1975507bb1e44596@linux-foundation.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, 23 Nov 2020 11:17:43 -0800 Lokesh Gidra wrote: > > > A future patch adds a knob allowing administrators to give some > > > processes the ability to create userfaultfd file objects only if they > > > pass UFFD_USER_MODE_ONLY, reducing the likelihood that these processes > > > will exploit userfaultfd's ability to delay kernel page faults to open > > > timing windows for future exploits. > > > > Can we assume that an update to the userfaultfd(2) manpage is in the > > works? > > > Yes, I'm working on it. Can the kernel version which will have these > patches be known now so that I can mention it in the manpage? 5.11, if all proceeds smoothly.