From mboxrd@z Thu Jan  1 00:00:00 1970
From: "pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de>
Subject: bug#35996: User account password got locked when booting old
	generation
Date: Sat, 1 Jun 2019 16:58:34 +0200
Message-ID: <20190601145834.f4wgm4oqmdyej7n5@pelzflorian.localdomain>
References: <20190529204517.mqn5xrw23xib4i3u@pelzflorian.localdomain>
	<877ea6l1on.fsf@gnu.org>
	<20190601055238.jkhefpupavz7aipi@pelzflorian.localdomain>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([209.51.188.92]:52133)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1hX5TL-0001dD-EX
	for bug-guix@gnu.org; Sat, 01 Jun 2019 10:59:04 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1hX5TK-0001KL-Fn
	for bug-guix@gnu.org; Sat, 01 Jun 2019 10:59:03 -0400
Received: from debbugs.gnu.org ([209.51.188.43]:53106)
	by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16)
	(Exim 4.71) (envelope-from <Debian-debbugs@debbugs.gnu.org>)
	id 1hX5TK-0001KA-Bg
	for bug-guix@gnu.org; Sat, 01 Jun 2019 10:59:02 -0400
Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2)
	(envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1hX5TK-0002G2-7q
	for bug-guix@gnu.org; Sat, 01 Jun 2019 10:59:02 -0400
Sender: "Debbugs-submit" <debbugs-submit-bounces@debbugs.gnu.org>
Resent-Message-ID: <handler.35996.B35996.15594011198643@debbugs.gnu.org>
Content-Disposition: inline
In-Reply-To: <20190601055238.jkhefpupavz7aipi@pelzflorian.localdomain>
List-Id: Bug reports for GNU Guix <bug-guix.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/bug-guix>,
	<mailto:bug-guix-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/bug-guix/>
List-Post: <mailto:bug-guix@gnu.org>
List-Help: <mailto:bug-guix-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/bug-guix>,
	<mailto:bug-guix-request@gnu.org?subject=subscribe>
Errors-To: bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org
Sender: "bug-Guix" <bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org>
To: Ludovic =?UTF-8?Q?Court=C3=A8s?= <ludo@gnu.org>
Cc: 35996@debbugs.gnu.org

On Sat, Jun 01, 2019 at 07:52:38AM +0200, pelzflorian (Florian Pelz) wrote:
> I wonder what would change /etc/shadow.
> 

If the error occurred on common non-Guix distros, it hopefully would
have been fixed before, maybe.  Of course Guix recreates /etc/shadow
much more frequently.

Guix appears to add shadow files atomically in gnu/build/accounts.scm.
I do not know if there could have been an error reading the old shadow
file, e.g. because it is locked or something?

The elogind source code in src/basic/user-util.c contains code for
locking /etc/shadow, with a comment that explains why its lckpwdf is
implemented differently from shadow-utils.

AccountsService appears to only be usable for reading /etc/shadow, not
for writing it, contrary to what the Guix manual claims (??).  For
writing passwords, gnome-control-center does not use AccountsService,
it calls /usr/bin/passwd directly in its source code in
panels/user-accounts/run-passwd.c.

Regards,
Florian