From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756340AbcHCINI (ORCPT ); Wed, 3 Aug 2016 04:13:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35018 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757242AbcHCIMc (ORCPT ); Wed, 3 Aug 2016 04:12:32 -0400 Date: Wed, 3 Aug 2016 16:04:55 +0800 From: Eryu Guan To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Vivek Goyal , Miklos Szeredi Subject: Re: [PATCH 4.4 133/146] ovl: Copy up underlying inodes ->i_mode to overlay inode Message-ID: <20160803080455.GJ27776@eguan.usersys.redhat.com> References: <20160725203521.340401316@linuxfoundation.org> <20160725203526.838883455@linuxfoundation.org> <20160803073644.GH27776@eguan.usersys.redhat.com> <20160803074506.GA23998@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160803074506.GA23998@kroah.com> User-Agent: Mutt/1.6.1 (2016-04-27) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 03 Aug 2016 08:04:59 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 03, 2016 at 09:45:06AM +0200, Greg Kroah-Hartman wrote: > On Wed, Aug 03, 2016 at 03:36:44PM +0800, Eryu Guan wrote: > > On Mon, Jul 25, 2016 at 01:56:28PM -0700, Greg Kroah-Hartman wrote: > > > 4.4-stable review patch. If anyone has any objections, please let me know. > > > > > > ------------------ > > > > > > From: Vivek Goyal > > > > > > commit 07a2daab49c549a37b5b744cbebb6e3f445f12bc upstream. > > > > > > Right now when a new overlay inode is created, we initialize overlay > > > inode's ->i_mode from underlying inode ->i_mode but we retain only > > > file type bits (S_IFMT) and discard permission bits. > > > > > > This patch changes it and retains permission bits too. This should allow > > > overlay to do permission checks on overlay inode itself in task context. > > > > > > [SzM] It also fixes clearing suid/sgid bits on write. > > > > This patch introduced a hang when writing to suid file, fstests > > generic/355 could reproduce the hang easily, it only failed the test > > without this patch and didn't hang the kernel. > > > > Should we skip it for now and wait for a further fix? > > Does Linus's tree have the same problem? Yes, 4.7 kernel hangs as well. > > > (The 4.6-stable tree faces the same question) > > Are we just missing a patch to be applied here? AFAICT, no patch is available to fix it yet. But I've reported the bug to Miklos (in RH bugzilla). > > And this is already in the released stable kernels... This patch is not in 4.7-rc7, it first appears in 4.7 kernel, seems like the soak time is not long enough to let testings finish :) I finished my 4.7 kernel testing and identified the culprit this Monday. Thanks, Eryu