From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966172AbeEJSUB (ORCPT ); Thu, 10 May 2018 14:20:01 -0400 Received: from mx2.suse.de ([195.135.220.15]:40807 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757182AbeEJSUA (ORCPT ); Thu, 10 May 2018 14:20:00 -0400 Subject: Re: [PATCH -next 0/2] ipc/shm: shmat() fixes around nil-page To: Davidlohr Bueso , akpm@linux-foundation.org, aarcange@redhat.com Cc: joe.lawrence@redhat.com, gareth.evans@contextis.co.uk, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@kernel.org, ltp@lists.linux.it References: <20180503203243.15045-1-dave@stgolabs.net> From: Vlastimil Babka Message-ID: <8addf0c1-26cd-add9-fb9c-292cc3567014@suse.cz> Date: Thu, 10 May 2018 20:17:55 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180503203243.15045-1-dave@stgolabs.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/03/2018 10:32 PM, Davidlohr Bueso wrote: > Hi, > > These patches fix two issues reported[1] a while back by Joe and Andrea > around how shmat(2) behaves with nil-page. > > The first reverts a commit that it was incorrectly thought that mapping > nil-page (address=0) was a no no with MAP_FIXED. This is not the case, > with the exception of SHM_REMAP; which is address in the second patch. Can you add appropriate Fixes: tags if possible? I guess patch 1 is clear, dunno about patch 2... > I chose two patches because it is easier to backport and it explicitly > reverts bogus behaviour. Both patches ought to be in -stable and ltp > testcases need updated (the added testcase around the cve can be modified > to just test for SHM_RND|SHM_REMAP). CC'd ltp so they know :) Thanks, Vlastimil > > [1] lkml.kernel.org/r/20180430172152.nfa564pvgpk3ut7p@linux-n805 > > Thanks! > > Davidlohr Bueso (2): > Revert "ipc/shm: Fix shmat mmap nil-page protection" > ipc/shm: fix shmat() nil address after round-down when remapping > > ipc/shm.c | 19 +++++++++++-------- > 1 file changed, 11 insertions(+), 8 deletions(-) >