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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 9E0DBC43444 for ; Fri, 11 Jan 2019 19:19:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 806812184A for ; Fri, 11 Jan 2019 19:19:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732488AbfAKTTA (ORCPT ); Fri, 11 Jan 2019 14:19:00 -0500 Received: from relay.sw.ru ([185.231.240.75]:42894 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728201AbfAKTTA (ORCPT ); Fri, 11 Jan 2019 14:19:00 -0500 Received: from [172.16.25.12] by relay.sw.ru with esmtp (Exim 4.91) (envelope-from ) id 1gi2KQ-0006o6-FX; Fri, 11 Jan 2019 22:18:50 +0300 Subject: Re: [PATCH 1/3] mm/vmalloc: fix size check for remap_vmalloc_range_partial() 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 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 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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