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 E64EDC4167B for ; Fri, 16 Dec 2022 18:12:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 54C288E0002; Fri, 16 Dec 2022 13:12:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4FC6D8E0001; Fri, 16 Dec 2022 13:12:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3C42D8E0002; Fri, 16 Dec 2022 13:12:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 2882F8E0001 for ; Fri, 16 Dec 2022 13:12:26 -0500 (EST) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id E6C5C4056F for ; Fri, 16 Dec 2022 18:12:25 +0000 (UTC) X-FDA: 80248964250.04.4403FFE Received: from mail-pj1-f43.google.com (mail-pj1-f43.google.com [209.85.216.43]) by imf19.hostedemail.com (Postfix) with ESMTP id 4D7691A0027 for ; Fri, 16 Dec 2022 18:12:23 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Z8HAKYx0; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf19.hostedemail.com: domain of jeffxu@google.com designates 209.85.216.43 as permitted sender) smtp.mailfrom=jeffxu@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1671214343; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=9AvFs+mQ9NvsJS8PCk/jQ9HRlu8dyTK47yIOgmc4j1w=; b=PW/72ZytcW/1lUCwLlIQRJ18W0FFT4hrxjlpsrniHXTRwTkqqTnA2IocvF/2i8O4W/XSBY tI99KKp1uxBORIwQ560G1I1yLj+kiEgonCqQXTC3b8tkZGEaldj+Bhg5MZm9IHgRyCOESw OMlzZypnC5rfes2aT/H1OsbnzqEMdZE= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Z8HAKYx0; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf19.hostedemail.com: domain of jeffxu@google.com designates 209.85.216.43 as permitted sender) smtp.mailfrom=jeffxu@google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1671214343; a=rsa-sha256; cv=none; b=OCUVoWyv9VCztcokziRiB/jx7WZolG690pH4rE5avJQP+0ZMXgZeik4saZRdMg31vQsVBr nAtPlJ46vFlIIQfkVqFhXrnxC+roesCI4BRCzYTjUOXrZBKm64Z2o69xBfGUrlCTNnBeaG CXy83sKFXkgl58n+FaR6B/tA9FOXbog= Received: by mail-pj1-f43.google.com with SMTP id z8-20020a17090abd8800b00219ed30ce47so6882518pjr.3 for ; Fri, 16 Dec 2022 10:12:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=9AvFs+mQ9NvsJS8PCk/jQ9HRlu8dyTK47yIOgmc4j1w=; b=Z8HAKYx0UY/wu6NVqgsze4WbTymS+TIwPZKlAOTZHZNQvL+odF4DJP+a0EtqODJLG+ P6OR2GWtkeMbYmvG9vgv2EVGh3J+4D+435J4QzqYTHPz801yG/ElNzFzc7/IIh7SIkxd 1dVMIQ+yEGFdO3W9FFeH9PtvU6qCguIbrbDqPx8PTjBlhaYALLu6jUNAh2CbrRpACQoN zanigDW0F193AC03lAYwjlfHz9TYBVcNW3pu0tp/H67Eb8nVBA/mfn02U37Qy45uDRPP C880rQ57sQYeKFNFunkSqyeZ7oI6fmK8QlAoo2SLh5yC0g7ZhY3wiHgIu1sJqp9muigf yd9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=9AvFs+mQ9NvsJS8PCk/jQ9HRlu8dyTK47yIOgmc4j1w=; b=19fDkK0VUZw+6cW5rZIF/bZrbfck61GOBOWyMVYHmvVEA90CY5/Y3Rj+kYZqI3AnPJ cO4DmvLR7RtPgYSyJSNqCz4gGhXxeWmfh0G3PFLa9XITcaQ2J8CWkBZ7k2/9ty+1lJY0 jbD6MAuYwz5tUZhznNxsdDM60A4AEJN3TPMAWX1ebcY25+7c8p4tz/fiS0bD1sHiFhdy BXngxmplhGlm3b4MYSnzoVhWSdCOEL4pTCRG7u77P7c+dudsb/k+ytuOrkwXErYJIU5C 9NGQtu36y0xdpWXmYWo9NEH0xGw/xeNe5f34Q/aIBkgVyz8pmJNwWtUIFW2irx+ZbS5v JbDg== X-Gm-Message-State: ANoB5plJDVJGrEflnoI8J6hvnZgHV/AG36SwxTk7PFGIH2J8HAwf1Mi/ r5XdJC7zJjxjKRnpUldxuSQnskoGFv5dmUacPil/rA== X-Google-Smtp-Source: AA0mqf78wqBM9aLl5xrt1webKvseMwn62xPSVHCYh0jx15lTP5g9KIcnYuXdLMWYz0eZo7MsT6YbznTDbXh4vw3ArEc= X-Received: by 2002:a17:903:3052:b0:189:63ef:ef3b with SMTP id u18-20020a170903305200b0018963efef3bmr66036808pla.112.1671214341841; Fri, 16 Dec 2022 10:12:21 -0800 (PST) MIME-Version: 1.0 References: <20221207154939.2532830-1-jeffxu@google.com> <20221207154939.2532830-4-jeffxu@google.com> <202212080821.5AE7EE99@keescook> <20221216094259.bec91e4abd6cf54a05ce2813@linux-foundation.org> In-Reply-To: <20221216094259.bec91e4abd6cf54a05ce2813@linux-foundation.org> From: Jeff Xu Date: Fri, 16 Dec 2022 10:11:44 -0800 Message-ID: Subject: Re: [PATCH v6 3/6] mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC To: Andrew Morton Cc: Peter Xu , Kees Cook , jeffxu@chromium.org, skhan@linuxfoundation.org, dmitry.torokhov@gmail.com, dverkamp@chromium.org, hughd@google.com, jorgelo@chromium.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, jannh@google.com, linux-hardening@vger.kernel.org, kernel test robot Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 4D7691A0027 X-Stat-Signature: y5b7w7ushxn7pquammu5giiseqmr4uak X-HE-Tag: 1671214343-982946 X-HE-Meta: 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 WcYGSSUY Hi530a3W2eXjerTzPLWHj2YDXP728xgkVrm2EPq93mL3J82zU3lpl59LwQNuK0pq1Wj0kLFjAlzAWwg6f+UR/0ZoQCJfrfKjWtjpgxcQ6sHUtpQF7NJe+NfoK2KCmajUgqFnS 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 Fri, Dec 16, 2022 at 9:43 AM Andrew Morton wrote: > > On Fri, 16 Dec 2022 09:15:40 -0800 Jeff Xu wrote: > > > On Fri, Dec 16, 2022 at 7:47 AM Peter Xu wrote: > > > > > > Hi, Jeff, > > > > > > On Thu, Dec 08, 2022 at 02:55:45PM -0800, Jeff Xu wrote: > > > > > > + if (!(flags & (MFD_EXEC | MFD_NOEXEC_SEAL))) { > > > > > > [...] > > > > > > > > > + pr_warn_ratelimited( > > > > > > + "memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=%d '%s'\n", > > > > > > + task_pid_nr(current), get_task_comm(comm, current)); > > > > > > This will be frequently dumped right now with mm-unstable. Is that what it > > > wanted to achieve? > > > > > > [ 10.822575] memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=491 'systemd' > > > [ 10.824743] memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=495 '(sd-executor)' > > > ... > > > > > > If there's already a sane default value (and also knobs for the user to > > > change the default) not sure whether it's saner to just keep it silent as > > > before? > > > > > Thanks for your comments. > > > > The intention is it is a reminder to adjust API calls to explicitly > > setting this bit. > > Do we need to warn more than once per boot? If not, use pr_warn_once()? > Once per boot seems too little, it would be nice if we can list all processes. I agree ratelimited might be too much. There is a feature gap here for logging. Kees, what do you think ? > > The sysctl vm.memfd_noexec = 0 1 is for transaction to the final > > state, and 2 depends on API call setting this bit. > > > > The log is ratelimited, and there is a rate limit setting: > > /proc/sys/kernel/printk_ratelimit > > /proc/sys/kernel/printk_ratelimit_burst > > >