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 89A9BC636D3 for ; Mon, 6 Feb 2023 17:05:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E84B66B0072; Mon, 6 Feb 2023 12:05:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E34B46B0073; Mon, 6 Feb 2023 12:05:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CD52C6B0074; Mon, 6 Feb 2023 12:05:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id BF3366B0072 for ; Mon, 6 Feb 2023 12:05:10 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 96D47A053B for ; Mon, 6 Feb 2023 17:05:10 +0000 (UTC) X-FDA: 80437492380.02.6CDE956 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf23.hostedemail.com (Postfix) with ESMTP id E0242140019 for ; Mon, 6 Feb 2023 17:05:06 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=eRJ+z2+x; spf=pass (imf23.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1675703107; 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=RRuABWwbPuY7o8ID2NLGTa56ZHzYzGcHYdmRVwotXpo=; b=L+0IYSIBSFsMzoF79ZtTXpQmfFKLf0b51BsGhXgwCpGj+96CuAhW9Qr6PdmcBwrfeY7fT/ 6b+9+upqgCKp9hd0Br8Yuxv096exep9GeU7xmRwjqzu1NtDO+pCjqo85VFyZedqL34uy8C 8om4jSL1SmSS21+3juToObuGGZ+6t/g= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=eRJ+z2+x; spf=pass (imf23.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1675703107; a=rsa-sha256; cv=none; b=4q03z4rTJfbr4YL3xLuMtQyipdnEOxokbI2znBxcnj52RpqUyt5ZcyW06Cz5+Kmwx8Egs1 qZV1Itm4iKmSOYpz+cvtJvhaAMi62OjyYNuT9Wof2Wi2i2QMu+31FQGxqAHCYJiB8cmVoH WoxEug9LLdA+mVSnutGc1Qcjsq2Y+0M= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675703106; h=from:from: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; bh=RRuABWwbPuY7o8ID2NLGTa56ZHzYzGcHYdmRVwotXpo=; b=eRJ+z2+xzuEWohaLKragMTwUTliaOCze+dyDRYV/qklCIscfTXAbAloejjQcUZCIFWYM4Y G8zmGM4WOaIIMzPQkCQ3sxFqHYWiIK/4bofKrBj+pQd79kxq6twsWD648Qg58+FuhGE/ox a+1la2nIUqVrGETl4lCnkQOQUcpaxNg= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-588-68YxDY-tO1uxWZwO6cKpLA-1; Mon, 06 Feb 2023 12:05:04 -0500 X-MC-Unique: 68YxDY-tO1uxWZwO6cKpLA-1 Received: by mail-wm1-f72.google.com with SMTP id o31-20020a05600c511f00b003dc53da325dso9235862wms.8 for ; Mon, 06 Feb 2023 09:05:04 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=RRuABWwbPuY7o8ID2NLGTa56ZHzYzGcHYdmRVwotXpo=; b=Dd85Dk13/+EXUDXSEx2Fjstjeta3bmAIx/KmaScqAe4SSkvdNd3g4TXNDt4F9a6xHM buSugEgZVa/whbWI6w9Q3hmhVzF4I/ZEZRVL0ic8BzoQNB3NeKsiV+0PoS5Ou/OrF02x vytiH9typaqzH/+Ko6awLkN5Q9teK1Csf+y3P4CgUWhOTEWcAJdIP6kxBP3Usu66ViCY 1+ie1alfTAUnSDaW6OqsPVGfBq96PBHzggvXH9qKcplEn+S4bUjXeLJS94oolyM81PJx /YStoWCMtoO7Jo9xPytjL/s/xaeN3XLRdipEnaP+gd+oUohR6c76i0q/DCr1hEnEC9BF xGYg== X-Gm-Message-State: AO0yUKWDkYOvh7pZDOjPuX8FUvGdV9F8K+24t36nVzb+6DeM/WEdwsHt D5aR0qxwz4Am4HEN1XjsltvI7lV1QDM/am001vKBBOJGvBgLdE3QbJasYX45Uy2W7Z6UjpO8rn4 SZwl1p5u4rEk= X-Received: by 2002:adf:e789:0:b0:2c3:e899:1b85 with SMTP id n9-20020adfe789000000b002c3e8991b85mr5020499wrm.15.1675703103615; Mon, 06 Feb 2023 09:05:03 -0800 (PST) X-Google-Smtp-Source: AK7set/97j9/fTK+ajoxpMOBwgtFwLcRSLa7e7zHErAKww1OfTxXfUilcAtjtds5pUfMGNUX4P/6fQ== X-Received: by 2002:adf:e789:0:b0:2c3:e899:1b85 with SMTP id n9-20020adfe789000000b002c3e8991b85mr5020480wrm.15.1675703103388; Mon, 06 Feb 2023 09:05:03 -0800 (PST) Received: from ?IPV6:2003:cb:c704:6200:8129:46d3:fa82:23f8? (p200300cbc7046200812946d3fa8223f8.dip0.t-ipconnect.de. [2003:cb:c704:6200:8129:46d3:fa82:23f8]) by smtp.gmail.com with ESMTPSA id p12-20020a5d48cc000000b00241fab5a296sm9152844wrs.40.2023.02.06.09.05.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 06 Feb 2023 09:05:02 -0800 (PST) Message-ID: <10a3929a-7109-169f-6e42-e51c83305567@redhat.com> Date: Mon, 6 Feb 2023 18:05:01 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH v3 1/4] mm/mlock: return EINVAL if len overflows for mlock/munlock To: mawupeng , akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kuleshovmail@gmail.com, aneesh.kumar@linux.ibm.com References: <20230128063229.989058-1-mawupeng1@huawei.com> <20230128063229.989058-2-mawupeng1@huawei.com> <753c53d3-84a6-da73-4121-0db4a71e4fde@redhat.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: E0242140019 X-Stat-Signature: 556nkfr8ceu95x1cpxiap4hkdiqob8rq X-Rspam-User: X-HE-Tag: 1675703106-37069 X-HE-Meta: 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 IAfFXa7w XF/GUPdvuEI7Oed3DgHfrKZ8fl3Sm0nLyw4mZdoaGaKsmzCXJqOA7h70yjUrvGOo5fVNyZzywG+rfEETOs+ll6QKBRQIWce4XXx7Yx4oiBKGk1li/1Lee+zIbEPVmnjjkv4t3nwRGdc+VzUP3aoE8ndiP6Cn+yygjtKVmd4/iOM3w7nMHd2XztxznznrFoe+rw6Pj/3bBfKlBnX0e0B7B2dmVZeT4hXEYJyycyfGgKzNyK+X8NxTXz7GKY3iS6t1SQArJtNS35jjGW3jZ29oVq49EUQCAxvUMMSpGUrp4gB6XH3KPnFXP+3CYakjMUz2kFfVypOGgYiEyB8uw3tScG4QdwgxEvXQFEFRn7JHZgl746xdxKndfeydiwua5S04ADhAKCuwcrVFHMTetZDBVbtyDUiyc/mJ8wG271ogRtc9HowM= 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 06.02.23 01:48, mawupeng wrote: > > > On 2023/2/4 1:14, David Hildenbrand wrote: >> On 28.01.23 07:32, Wupeng Ma wrote: >>> From: Ma Wupeng >>> >>> While testing mlock, we have a problem if the len of mlock is ULONG_MAX. >>> The return value of mlock is zero. But nothing will be locked since the >>> len in do_mlock overflows to zero due to the following code in mlock: >>> >>>    len = PAGE_ALIGN(len + (offset_in_page(start))); >>> >>> The same problem happens in munlock. >>> >>> Add new check and return -EINVAL to fix this overflowing scenarios since >>> they are absolutely wrong. >>> >>> Return 0 early to avoid burn a bunch of cpu cycles if len == 0. >>> >>> Signed-off-by: Ma Wupeng >>> --- >>>   mm/mlock.c | 14 ++++++++++++-- >>>   1 file changed, 12 insertions(+), 2 deletions(-) >>> >>> diff --git a/mm/mlock.c b/mm/mlock.c >>> index 7032f6dd0ce1..eb09968ba27f 100644 >>> --- a/mm/mlock.c >>> +++ b/mm/mlock.c >>> @@ -478,8 +478,6 @@ static int apply_vma_lock_flags(unsigned long start, size_t len, >>>       end = start + len; >>>       if (end < start) >>>           return -EINVAL; >>> -    if (end == start) >>> -        return 0; >>>       vma = mas_walk(&mas); >>>       if (!vma) >>>           return -ENOMEM; >>> @@ -575,7 +573,13 @@ static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t fla >>>       if (!can_do_mlock()) >>>           return -EPERM; >>>   +    if (!len) >>> +        return 0; >>> + >>>       len = PAGE_ALIGN(len + (offset_in_page(start))); >>> +    if (!len) >>> +        return -EINVAL; >>> + >>>       start &= PAGE_MASK; >> >> The "ordinary" overflows are detected in apply_vma_lock_flags(), correct? > > Overflow is not checked anywhere however the ordinary return early if len == 0 is detected in apply_vma_lock_flags(). > I meant the end = start + len; if (end < start) return -EINVAL; Essentially, what I wanted to double-check is that with your changes, we catch all kinds of overflows as documented in the man page, correct? -- Thanks, David / dhildenb