From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman) Subject: Re: [CFT][PATCH 00/10] Making new mounts of proc and sysfs as safe as bind mounts (take 2) Date: Thu, 28 May 2015 14:57:51 -0500 Message-ID: <87382gh3uo.fsf@x220.int.ebiederm.org> References: <87pp63jcca.fsf@x220.int.ebiederm.org> <87siaxuvik.fsf@x220.int.ebiederm.org> <87wq004im1.fsf@x220.int.ebiederm.org> <20150528140839.GD28842@ubuntumail> <55676E32.3050006@nod.at> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55676E32.3050006-/L3Ra7n9ekc@public.gmane.org> (Richard Weinberger's message of "Thu, 28 May 2015 21:36:18 +0200") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Richard Weinberger Cc: Kenton Varda , Greg Kroah-Hartman , Linux Containers , Serge Hallyn , Andy Lutomirski , Seth Forshee , Michael Kerrisk-manpages , Linux API , Linux FS Devel , Tejun Heo List-Id: containers.vger.kernel.org Richard Weinberger writes: > Am 28.05.2015 um 16:08 schrieb Serge Hallyn: >> Quoting Andy Lutomirski (luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org): >>> On Fri, May 22, 2015 at 10:39 AM, Eric W. Biederman >>> wrote: >>>> I had hoped to get some Tested-By's on that patch series. >>> >>> Sorry, I've been totally swamped. >>> >>> I suspect that Sandstorm is okay, but I haven't had a chance to test >>> it for real. Sandstorm makes only limited use of proc and sysfs in >>> containers, but I'll see if I can test it for real this weekend. >> >> Testing this with unprivileged containers, I get >> >> lxc-start: conf.c: lxc_mount_auto_mounts: 808 Operation not permitted - error mounting sysfs on /usr/lib/x86_64-linux-gnu/lxc/sys/devices/virtual/net flags 0 >> > > FWIW, it breaks also libvirt-lxc: > Error: internal error: guest failed to start: Failed to re-mount /proc/sys on /proc/sys flags=1021: Operation not permitted Interesting. I had not anticipated a failure there? And it is failing in remount? Oh that is interesting. That implies that there is some flag of the original mount of /proc that the remount of /proc/sys is clearing, and that previously The flags specified are current rdonly,remount,bind so I expect there are some other flags on proc that libvirt-lxc is clearing by accident and we did not fail before because the kernel was not enforcing things. What are the mount flags in a working libvirt-lxc? Eric