Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753313Ab3JFAWF (ORCPT ); Sat, 5 Oct 2013 20:22:05 -0400 Received: from mail-oa0-f46.google.com ([209.85.219.46]:38561 "EHLO mail-oa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752494Ab3JFAWC convert rfc822-to-8bit (ORCPT ); Sat, 5 Oct 2013 20:22:02 -0400 Date: Sat, 05 Oct 2013 19:22:00 -0500 From: Rob Landley Subject: Re: [RFC][PATCH 0/3] vfs: Detach mounts on unlink. To: Al Viro Cc: Linus Torvalds , "Eric W. Biederman" , Miklos Szeredi , "Serge E. Hallyn" , Linux-Fsdevel , Kernel Mailing List , Andy Lutomirski References: <87li281wx6.fsf_-_@xmission.com> <1381014462.1974.162@driftwood> <20131005232451.GX13318@ZenIV.linux.org.uk> In-Reply-To: <20131005232451.GX13318@ZenIV.linux.org.uk> (from viro@ZenIV.linux.org.uk on Sat Oct 5 18:24:51 2013) X-Mailer: Balsa 2.4.11 Message-Id: <1381018920.1974.167@driftwood> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; DelSp=Yes; Format=Flowed Content-Disposition: inline Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1322 Lines: 35 On 10/05/2013 06:24:51 PM, Al Viro wrote: > On Sat, Oct 05, 2013 at 04:17:55PM -0700, Linus Torvalds wrote: > > On Sat, Oct 5, 2013 at 4:07 PM, Rob Landley wrote: > > > > > > A todo item I've had _forever_ is fixing chroot() to not be > broken so that > > > you can trivially break out of a chroot via: > > > > What drugs are you on? > > > > Your example is moronic, and against all _documented_ uses of > chroot. > > ... and even fixing that example (chroot *can* be escaped, if you can > call chroot(2) - mkdir /foo, chdir /, chroot /foo, chroot .. and you > are out) Um, wasn't that my example? > the whole thing is idiocy - chroot() is not and has never been > root-proof > and anybody expecting it to be has failed to read any number of FAQs > out > there. Which is why I was proposing modifying it so lxc and containers didn't have to use pivot_root() instead, with all the logic to rehome existing processes and the weird "this path is relative the old root, this path is relative to the new root" syntax from initial ramdisks. Rob-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/