From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f197.google.com (mail-lj1-f197.google.com [209.85.208.197]) by kanga.kvack.org (Postfix) with ESMTP id 6B1618E0001 for ; Fri, 11 Jan 2019 14:18:56 -0500 (EST) Received: by mail-lj1-f197.google.com with SMTP id g12-v6so4026707lji.3 for ; Fri, 11 Jan 2019 11:18:56 -0800 (PST) Received: from relay.sw.ru (relay.sw.ru. [185.231.240.75]) by mx.google.com with ESMTPS id m20si57990147lfb.58.2019.01.11.11.18.54 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 11 Jan 2019 11:18:54 -0800 (PST) Subject: Re: [PATCH 1/3] mm/vmalloc: fix size check for remap_vmalloc_range_partial() References: <20190103145954.16942-1-rpenyaev@suse.de> <20190103145954.16942-2-rpenyaev@suse.de> From: Andrey Ryabinin Message-ID: <873d9ee8-9cee-b6f1-ca2c-f4da2d2ddfc0@virtuozzo.com> Date: Fri, 11 Jan 2019 22:19:12 +0300 MIME-Version: 1.0 In-Reply-To: <20190103145954.16942-2-rpenyaev@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Roman Penyaev Cc: Andrew Morton , Michal Hocko , Joe Perches , "Luis R. Rodriguez" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org On 1/3/19 5:59 PM, Roman Penyaev wrote: > area->size can include adjacent guard page but get_vm_area_size() > returns actual size of the area. > > This fixes possible kernel crash when userspace tries to map area > on 1 page bigger: size check passes but the following vmalloc_to_page() > returns NULL on last guard (non-existing) page. > > Signed-off-by: Roman Penyaev > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Andrey Ryabinin > Cc: Joe Perches > Cc: "Luis R. Rodriguez" > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Cc: stable@vger.kernel.org > --- Fixes: e69e9d4aee71 ("vmalloc: introduce remap_vmalloc_range_partial") Acked-by: Andrey Ryabinin