#272 - [X2Go-User] Session resume fails with AFS home directories

X2Go Bug report logs - #272
[X2Go-User] Session resume fails with AFS home directories

Reported by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

Date: Fri, 26 Jul 2013 14:48:01 UTC

Severity: normal

Found in version 4.0.1.3

Received: (at 272) by bugs.x2go.org; 16 Sep 2013 14:26:01 +0000
From sebastian.flothow@gip.com  Mon Sep 16 16:26:00 2013
X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on
	ymir.das-netzwerkteam.de
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	version=3.3.2
X-Greylist: delayed 508 seconds by postgrey-1.34 at ymir; Mon, 16 Sep 2013 16:26:00 CEST
Received: from hermes.gip.com (hermes.gip.com [213.139.134.71])
	by ymir (Postfix) with ESMTP id 915EA5DA79
	for <272@bugs.x2go.org>; Mon, 16 Sep 2013 16:26:00 +0200 (CEST)
Received: from localhost (localhost [127.0.0.1])
	by hermes.gip.com (Postfix) with ESMTP id 1BAAE17E8056;
	Mon, 16 Sep 2013 16:17:32 +0200 (CEST)
Received: from hermes.gip.com (localhost [127.0.0.1])
	by localhost (AvMailGate-3.2.1.26) id 19177-WvIBVe;
	Mon, 16 Sep 2013 14:17:32 -0000
Received: from [10.0.9.42] (devlin042.gip.local [10.0.9.42])
	by hermes.gip.com (Postfix) with ESMTPSA id 154FD17E8056;
	Mon, 16 Sep 2013 16:17:32 +0200 (CEST)
Message-ID: <523712FB.2060200@gip.com>
Date: Mon, 16 Sep 2013 16:17:31 +0200
From: Sebastian Flothow <sebastian.flothow@gip.com>
User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130801 Thunderbird/17.0.8
MIME-Version: 1.0
To: 272@bugs.x2go.org
CC: x2go-user@lists.berlios.de
Subject: Re: [X2Go-User] Session resume fails with AFS home directories
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
X-AntiVirus: checked by Avira MailGate (version: 3.2.1.26; AVE: 8.2.12.120; VDF: 7.11.102.198; host: hermes); id=19177-WvIBVe

I did some further testing, and the resume failures are indeed due to missing AFS tokens. When suspending a session, the SSH connection is closed, sshd will call pam_close_session(), which means that pam_krb5 and pam_afs_session will delete the user's ticket/token (resp.). The session therefore loses access to the home directory and appears to freeze up, preventing it from being resumed. Both pam_krb5 and pam_afs_session accept retain_after_close as a parameter, which disables the delete-on-close behavior. With this parameter set, it becomes possible to resume sessions, unless the AFS token has expired. This solves at least the case where the user reconnects quickly (eg. after a short network outage), but it still means sessions will become unresumable when left unused for a few days. I guess the only way to avoid this is to not store session data in the home directory. Can X2go be configured such that it uses eg. /tmp or /var/lib for this purpose?

X2Go Developers <owner@bugs.x2go.org>. Last modified: Thu Apr 25 08:48:27 2024; Machine Name: ymir.das-netzwerkteam.de

X2Go Bug tracking system

Debbugs is free software and licensed under the terms of the GNU Public License version 2. The current version can be obtained from https://bugs.debian.org/debbugs-source/.

X2Go Bug report logs - #272 [X2Go-User] Session resume fails with AFS home directories

X2Go Bug report logs - #272
[X2Go-User] Session resume fails with AFS home directories