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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 34AB8C4361B for ; Tue, 15 Dec 2020 19:07:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AC4C922ADC for ; Tue, 15 Dec 2020 19:07:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AC4C922ADC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 300536B0036; Tue, 15 Dec 2020 14:07:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2B0386B005D; Tue, 15 Dec 2020 14:07:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1C6A76B0068; Tue, 15 Dec 2020 14:07:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0247.hostedemail.com [216.40.44.247]) by kanga.kvack.org (Postfix) with ESMTP id 078346B0036 for ; Tue, 15 Dec 2020 14:07:49 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id BE2441EF2 for ; Tue, 15 Dec 2020 19:07:48 +0000 (UTC) X-FDA: 77596451016.30.quilt54_4f1036527425 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id 99A01180B3C85 for ; Tue, 15 Dec 2020 19:07:48 +0000 (UTC) X-HE-Tag: quilt54_4f1036527425 X-Filterd-Recvd-Size: 3034 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Tue, 15 Dec 2020 19:07:47 +0000 (UTC) IronPort-SDR: oczgUoEqcemxgCMqpUHFopKagBDRwd9T8FPLX/2cq1f2adltmquOh4jAPRUvjpD9oOLHPMPtKs NeDpHq4MiAaA== X-IronPort-AV: E=McAfee;i="6000,8403,9836"; a="259661725" X-IronPort-AV: E=Sophos;i="5.78,422,1599548400"; d="scan'208";a="259661725" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2020 11:07:46 -0800 IronPort-SDR: 2R7qno6uaUVqcZsV2isIIHY5z2yXvnV5wP5VbcKQPY9aSpW8qFHW8ISmNJ7e6oV49hEGLzXzNs tlv3nIRLiYJg== X-IronPort-AV: E=Sophos;i="5.78,422,1599548400"; d="scan'208";a="556432183" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2020 11:07:40 -0800 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1kpFge-00Ea78-IL; Tue, 15 Dec 2020 21:08:40 +0200 Date: Tue, 15 Dec 2020 21:08:40 +0200 From: Andy Shevchenko To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: Andrew Morton , airlied@linux.ie, alexander.shishkin@linux.intel.com, bgolaszewski@baylibre.com, bp@alien8.de, bp@suse.de, cl@linux.com, daniel.vetter@ffwll.ch, daniel@ffwll.ch, gustavo@padovan.org, iamjoonsoo.kim@lge.com, james.morse@arm.com, jasowang@redhat.com, linus.walleij@linaro.org, linux-mm@kvack.org, maarten.lankhorst@linux.intel.com, mchehab@kernel.org, mm-commits@vger.kernel.org, mripard@kernel.org, mst@redhat.com, penberg@kernel.org, perex@perex.cz, rientjes@google.com, rric@kernel.org, sumit.semwal@linaro.org, tiwai@suse.com, tiwai@suse.de, tony.luck@intel.com, torvalds@linux-foundation.org, tzimmermann@suse.de, vbabka@suse.cz Subject: Re: [patch 012/200] mm: slab: clarify krealloc()'s behavior with __GFP_ZERO Message-ID: <20201215190840.GU4077@smile.fi.intel.com> References: <20201215030350.xC0HoDUgG%akpm@linux-foundation.org> <2172e342-e73f-a759-fce5-8b94daafd506@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <2172e342-e73f-a759-fce5-8b94daafd506@amd.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Content-Transfer-Encoding: quoted-printable 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 Tue, Dec 15, 2020 at 03:30:44PM +0100, Christian K=F6nig wrote: > Am 15.12.20 um 04:03 schrieb Andrew Morton: ... > Question: Can the fact that __GFP_ZERO is effectively ignored cause an > information leak if new size is larger than old size and the array is > somehow copied to user space? >=20 > I think the answer is no, but just wanted to double check. Maybe we sho= uld > note that here. kmalloc()/kmalloc_array()/etc has the same. Should it be mentioned there = as well? --=20 With Best Regards, Andy Shevchenko