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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 22217CA5FB1 for ; Wed, 30 Sep 2026 11:43:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1B1626B0088; Wed, 30 Sep 2026 07:43:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1888D6B008A; Wed, 30 Sep 2026 07:43:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 09E676B0093; Wed, 30 Sep 2026 07:43:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id D59726B0088 for ; Wed, 30 Sep 2026 07:43:14 -0400 (EDT) Received: from smtpin22.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 6E45CA72DD for ; Wed, 30 Sep 2026 11:43:14 +0000 (UTC) X-FDA: 85270242708.22.468997A Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf27.hostedemail.com (Postfix) with ESMTP id B575540008 for ; Wed, 30 Sep 2026 11:43:12 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=UEqFEIN1; spf=pass (imf27.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@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=1790768592; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=9uMVOqMiTX1K2XJQJxXE/LwrK8qNT7KXfojMzsVrx8U=; b=GUWlKD5IjaAg4SkVEsAKFa62Kj5IlKyrzXWp51UQQNWoBbimZuTfRO2LFtFFRGWnAtOnai xvzRdxnOCKyaCKRy5ISPnXZCGCO1qQMj/ZBbadafNSrzYmOhm6+X0mhP86ov1oUkwCLpjT 4MT9rwUGEQgrXjSesRiHNBa1QKoR+es= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=UEqFEIN1; spf=pass (imf27.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790768592; b=WDpdHoZkdeMUWUfz7norz8+9D/8+JGHYY738DvfVmfBO/CGOuPbcZXUMpe5Nk3FDaFyKVg th6BklX3NGlLYqc9edPAt1LtFsvhI5SlQb7zH3mH9/lxD5hwrzhuobiszVKOPm86hoFb6u fkUowyOK7djTF4DVOwQZ41GA5ytcuGw= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 8E18760008; Wed, 30 Sep 2026 11:43:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3F051F000FF; Wed, 30 Sep 2026 11:43:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790768591; bh=9uMVOqMiTX1K2XJQJxXE/LwrK8qNT7KXfojMzsVrx8U=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=UEqFEIN12S69RdNlJmEU6fp0nKhSRNYo2596rxvjxQjmx2chUXZZo9T5Kr7lEEHGq d53074fabPnHx0Ed7wzeOZvSrzDEhKFOeMprzqQxseYpQ8SM7G8hq5VL9Eqc3Q5NEz ZUuZGVoVk1oYCpHTte4evrGtrM6DvnkAiuTfQWIfuyHETHInxUkKBPYAfYsbQHrJg3 WZqR2SBTQTSK+VdsJaAThusyW1cmH2rKwTuvE49eqDpsoviY9EFUc1e1GJnZCOb9l9 cXXviEcuLrkC6xBcgysrrfRB8GhwEtKQFh6CKxR8Ft2+934XQpBCsTmMG9PsH8dQGG iQnFD6ZxPIHgA== Message-ID: <7d120555-0c31-474f-893b-e5ee3466ead4@kernel.org> Date: Wed, 30 Sep 2026 13:43:05 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/mlock: fix zero-length request normalization and integer overflows To: =?UTF-8?B?67CV7YOc7ISgL+y7tO2TqO2EsMK3QUntlZnrtoA=?= , "Lorenzo Stoakes (ARM)" Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , Michal Hocko , Mike Rapoport , Suren Baghdasaryan , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <179066531783.50175.13377521828379196177@dgu.ac.kr> <3a95d0e5-7969-4b0d-988a-ead62b06b6f5@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Stat-Signature: zn9cgunqgatea93zwc8xumm1jixfkfon X-Rspamd-Queue-Id: B575540008 X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1790768592-641558 X-HE-Meta: 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 xzaloVp1 P7eoMLygv6ANUu4jUzWGdSuEo7Fj7uwcl+BGg09V9K6sQmccQ7ytS2zP6rdXi9Q1nbj0Z248E/E/sZiwC+N/6HN6SXCX6TXLfWlMdNW5oi6LOZci8PHVoumOsb1zw4xLl6ad5wyHnwwojkID20+l07zASeVnV+q6nDd6octq8befD92kvBtxXDcLq1bEGFuOdKXKdSPYduMxC2Pwgm26ygUauyYIWcBwho8sl6De4IhHEsf2rswkvcKDjLZuDvKYGv2LOqAuCU2ae+qjuOVIoNuKfwjdZYfL5MeSd Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/29/26 11:39, 박태선/컴퓨터·AI학부 wrote: > Understood, and thank you for the feedback. > > I sincerely apologize for the poor code quality and flawed helper > design. I will be much more careful with commenting and ensure future > contributions strictly adhere to kernel guidelines. > > I will drop this patch. > > For David's question regarding reproducers and user-visible issues, in > case it is helpful if the core team addresses this later, > here is what is observed from a small test program wrote checking > /proc/self/smaps on an unpatched kernel: > > $ ./test_mlock > mlock(p, -1UL) : ret=0, locked=0 (silent success without actually locking) > mlock(p + 5, 0) : ret=0, locked=1 (0-length request falsely locks 4KB page) > munlock(p + 5, 0) : ret=0, locked=0 (0-length request falsely unlocks 4KB page) > > Thank you all for your time and the review. The CI seems to complain about test failures: # --------------------------------------------- # running sudo -u nobody sh -c ./on-fault-limit # --------------------------------------------- # TAP version 13 # 1..1 # ok 1 The map failed respecting mlock limits # # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0 # [PASS] ok 1 sudo -u nobody sh -c ./on-fault-limit # --------------------------- # running ./mlock-random-test # --------------------------- # TAP version 13 # 1..2 # ok 1 test_mlock_within_limit # Bail out! mlock2() succeeds? on 0x7ffff7d2a010(393216) mlock0x7ffff7d44a72(278478) # # Planned tests != run tests (2 != 1) # # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0 # [FAIL] not ok 2 mlock-random-test # exit=1 So is this patch doing more harm than good? -- Cheers, David