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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 94C72C28D13 for ; Wed, 3 Mar 2021 01:02:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77F876023B for ; Wed, 3 Mar 2021 01:02:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241297AbhCCAw3 (ORCPT ); Tue, 2 Mar 2021 19:52:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244061AbhCBRkL (ORCPT ); Tue, 2 Mar 2021 12:40:11 -0500 Received: from mail-io1-xd2f.google.com (mail-io1-xd2f.google.com [IPv6:2607:f8b0:4864:20::d2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77813C06178A for ; Tue, 2 Mar 2021 09:39:10 -0800 (PST) Received: by mail-io1-xd2f.google.com with SMTP id f20so22610313ioo.10 for ; Tue, 02 Mar 2021 09:39:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=f1fS5NpFbu6beXKjjCtL5o94IGkB8gbIgEDDeVSe160=; b=jKSeCamb1tJMFb0v1+PCv4F4YShNUZG9qJIWxNEnlJkUpgAtZyugNZqvNVGa1nmr9X B7pPwjROdcsb8k3Ie8e7fmAiFLko64dBr6k2et3Zcq6TU0KzYFMkHxfhAkCW7J7Kjtux I1ourN6WVpzqF+OaduKSxTCqkrE0JccUZTaPs8v7AJLp1+mVwW6jamTFdH9FD/dgHWBv 4ROKt0FlgVx9cro++Zpmcmi5FZBFc4ucK0jPKpPj5BsIVSFwtgmAoSuIdKI3OEKI4C03 Nttmn7QJE07PhfXtlP3qbOlqr0ZbLT44FkmynwtRFILLyj7v3HRl+XbLk0aj33cVDgDX SUlQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=f1fS5NpFbu6beXKjjCtL5o94IGkB8gbIgEDDeVSe160=; b=CldFE900Bbnio7klGk4zavQ/Clv/pcZeP57YwrSLAOQpKgM49/WblUpNWS06muHmHa fOg+7pQ7MS1DJE7G2bWOMFfgYnwH3ITxuyoC6wIn3GqKMiS9ztXeIa75eCzWrQe45tYu 8n5VI9eggo7BKmppSmqH1I3HJZ9oWAoCmDFW1apjAwWn6ZwtqNMqRQDybXHJniw7VDlP zaxJAUb62RuwRZivuNdl9FI618eUZ1id2WhGqrW4trezxqbiZtFT/Hmb3joOjcfBtOAA TnsrF5y7rULzs60fydmDX1KpWOHE30FtGm+NMmATOPAEZltmsVh4d6H7YIROYR3zbM9N yffA== X-Gm-Message-State: AOAM531iSOMvoT3Wbo3lRZjxU9y9gG+ybMbCO4NmnEXTdwiX4EGOCQJ/ lI9DD1D4i06fgeMwkDkEKHA+eCSd2dIsfw== X-Google-Smtp-Source: ABdhPJwYx646uI12383G6cXSip/WSHz1MeSEL1EHGinB9nkBLqNAFX2x4OtiP3kVoYD4w8LG46nOSQ== X-Received: by 2002:a05:6638:3809:: with SMTP id i9mr1973536jav.24.1614706749753; Tue, 02 Mar 2021 09:39:09 -0800 (PST) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id w6sm10882380ilm.38.2021.03.02.09.39.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 02 Mar 2021 09:39:09 -0800 (PST) Subject: Re: [PATCH 4.19 21/57] proc: dont allow async path resolution of /proc/self components To: Yang Yingliang , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, Sasha Levin , yangerkun , Cheng Jian References: <20201201084647.751612010@linuxfoundation.org> <20201201084650.205087954@linuxfoundation.org> From: Jens Axboe Message-ID: <395dd137-70d5-e915-92b5-b2a18f44badc@kernel.dk> Date: Tue, 2 Mar 2021 10:39:08 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 3/2/21 1:40 AM, Yang Yingliang wrote: > Hi, > > On 2020/12/1 16:53, Greg Kroah-Hartman wrote: >> From: Jens Axboe >> >> [ Upstream commit 8d4c3e76e3be11a64df95ddee52e99092d42fc19 ] >> >> If this is attempted by a kthread, then return -EOPNOTSUPP as we don't >> currently support that. Once we can get task_pid_ptr() doing the right >> thing, then this can go away again. > > https://www.spinics.net/lists/io-uring/msg05297.html > > This patch seems used for io-wq worker which is merged in > > v5.5-rc1, why we need this in linux-4.19.y ? While that's true, it's also a sane safeguard in general. -- Jens Axboe