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 15B03E77188 for ; Tue, 7 Jan 2025 01:17:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8E6E96B00C9; Mon, 6 Jan 2025 20:17:16 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 86FFD6B00CC; Mon, 6 Jan 2025 20:17:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 710446B00CE; Mon, 6 Jan 2025 20:17:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 4EF146B00C9 for ; Mon, 6 Jan 2025 20:17:16 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id CD23BA058D for ; Tue, 7 Jan 2025 01:17:15 +0000 (UTC) X-FDA: 82978892430.23.F4AF444 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf21.hostedemail.com (Postfix) with ESMTP id 464661C0006 for ; Tue, 7 Jan 2025 01:17:14 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=dpk+LaIM; spf=pass (imf21.hostedemail.com: domain of kees@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=kees@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1736212634; a=rsa-sha256; cv=none; b=rrzRtCz7Lqal2a1DDmBKQwIisGwTln0RcYxDsxubG0+RjP/beK9gUSP1jo6cAcUFRqQZ0J eIR2ca8juwOyBMSHOsI9jpwmHW7M0pJ3QLcvqAFFjhndaOmqUjy2KCxmxN6Jz3bKH6boDf qLrkOxn1CcR9voRPN0JvuiU2a8d6ipM= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=dpk+LaIM; spf=pass (imf21.hostedemail.com: domain of kees@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=kees@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1736212634; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Jok6FthgpVsMuTHauDbGgotuxwYHRYtBUcXaZHIS2QI=; b=Fx0lWz2ya8Ahcw8A+zIgjt/fitrR2qBZVAdtlrAtML7e0URmzxCDscnuihnA5TNYWOeXOE QiSdKh89eXhOfU8ZfDk9I2SvpEvV+m04myBsg2ldZsraQflSm2UchhN1M3AKHFy7eEjo/y t4R/dTF6NVLPWBE+QHWkq1iA6X7I8CU= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 398D65C6139; Tue, 7 Jan 2025 01:16:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06360C4CED2; Tue, 7 Jan 2025 01:17:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736212633; bh=kAVrCQjzZghGx/Mh/TnXhecmI2ef0AhPGBvN/Aj8emc=; h=Date:From:To:Subject:References:In-Reply-To:From; b=dpk+LaIMK1A26bZlbRyuwn8ixb/Il4rYdg9BPZKr+WqFHmKjCt/rXJ+T4CbdMT+P8 eXzNTGgu3STjCmzu+4POglK+Uq/mZPr57XZl7bi3IAHy4qB8O/+HvsGt1vgbBHn8Vz m6xN1oK+YJ4ZhknXWuE6ui1fuABxFC+YFlezOjDLBshBGhd8bX59qfC03Vu03iz3Vi /XUAJiFgOL+bmIZHZvPzsdz5HdaX1zPxR+e2SmmOPNj5no7M1B4+lEkJxLX8wucN3t Z/c0h5GGHRtU9pryz7ailccg7DjIM2y6NFXWW1iOeEzinRwJ7vlz2g4yUsPL1MHVfV va1n5a+DihdAA== Date: Mon, 6 Jan 2025 17:17:10 -0800 From: Kees Cook To: "Liam R. Howlett" , jeffxu@chromium.org, akpm@linux-foundation.org, jannh@google.com, torvalds@linux-foundation.org, adhemerval.zanella@linaro.org, oleg@redhat.com, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, linux-mm@kvack.org, jorgelo@chromium.org, sroettger@google.com, ojeda@kernel.org, adobriyan@gmail.com, anna-maria@linutronix.de, mark.rutland@arm.com, linus.walleij@linaro.org, Jason@zx2c4.com, deller@gmx.de, rdunlap@infradead.org, davem@davemloft.net, hch@lst.de, peterx@redhat.com, hca@linux.ibm.com, f.fainelli@gmail.com, gerg@kernel.org, dave.hansen@linux.intel.com, mingo@kernel.org, ardb@kernel.org, mhocko@suse.com, 42.hyeyoo@gmail.com, peterz@infradead.org, ardb@google.com, enh@google.com, rientjes@google.com, groeck@chromium.org, mpe@ellerman.id.au, Vlastimil Babka , Lorenzo Stoakes , Andrei Vagin , Dmitry Safonov <0x7f454c46@gmail.com>, Mike Rapoport , Alexander Mikhalitsyn Subject: Re: [PATCH v4 1/1] exec: seal system mappings Message-ID: <202501061713.823E772F@keescook> References: <20241125202021.3684919-1-jeffxu@google.com> <20241125202021.3684919-2-jeffxu@google.com> <202412171248.409B10D@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 464661C0006 X-Stat-Signature: nf3g3tmak7nfdn6yjqsib77jbbtbaoa6 X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1736212634-525233 X-HE-Meta: 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 zG0fw1CN 03Lq1lLECSpTdVgE6XA9VcYi9G29DE28+A9ARr1r9hTc7BwaWyz0p7Cay/r+4URAZsxnXCmfuIgfv4qzGXu++vepvoucWHimCyxOSisIcimyLXNXSoMfGQ6x01Q6xQWVytGhkbkk4EN/Hev/ox2gJEVAqiQ0KViiPfh6vNb/Z5MTrkkpbRuSy0/ncqhbnZQSoR+MAbJr78af5HN/b1vbk7vp0ll2Et6l6McwGGpUzmots+XcEI2pNgfOjCM+JlFJOat3KaRPYmrVFYmRY2SbtbjP7DnEdzKHUiJLt1LAbxC74i6UNohFS5yJ9bIOEFJto2CS8nLBxKIlxJUI= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000527, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Jan 03, 2025 at 03:48:23PM -0500, Liam R. Howlett wrote: > So we have at least two userspace uses that this will breaks: checkpoint > restore and now gVisor, but who knows what else? How many config > options before we decide this can't be just on by default? See my reply to Lorenzo, but I'm not arguing for it to be enabled by default. I was trying to show how we traditionally handle these kinds of features: putting their enablement behind a Kconfig and boot param that work together. That way distro kernels have it _available_ without making it _enabled_, and specialty kernels can have in enabled by default (and can disable it at boot if needed too). -- Kees Cook