network-manager-fortisslvpn breaks mode of /run/systemd/resolv/stub-resolv.conf

[Paul Smith]

(I'm not able to use ubuntu-bug as it fails with a 503 error trying to connect to the crash server)

I'm using Ubuntu 18.04.1 on 64bit Intel with:

network-manager 1.10.6-2ubuntu1
network-manager-fortisslvpn 1.2.8-1build1
network-manager-fortisslvpn-gnome 1.2.8-1build1
network-manager-gnome 1.8.10-2ubuntu1

systemd 237-3ubuntu10.3

When I connect then disconnect from my VPN using the network-manager-fortisslvpn VPN interface, it will break the permissions on /run/systemd/resolv/stub-resolv.conf such that I can't use DNS anymore until I fix the permissions.

On my system I see:

$ ls -al /etc/resolv.conf
lrwxrwxrwx 1 root root 39 Oct 22 2017 /etc/resolv.conf -> ../run/systemd/resolve/stub-resolv.conf

When there's no VPN connection, I see:

$ ls -al /run/systemd/resolve/
total 8
drwxr-xr-x 3 systemd-resolve systemd-resolve 100 Sep 19 23:05 ./
drwxr-xr-x 21 root root 480 Sep 15 14:19 ../
drwx------ 2 systemd-resolve systemd-resolve 60 Sep 19 23:05 netif/
-rw-r--r-- 1 systemd-resolve systemd-resolve 714 Sep 19 23:05 resolv.conf
-rw-r--r-- 1 systemd-resolve systemd-resolve 783 Sep 19 19:31 stub-resolv.conf

Now I start the fortisslvpn VPN:

$ ls -al /run/systemd/resolve/
total 16
drwxr-xr-x 3 systemd-resolve systemd-resolve 140 Sep 19 23:06 ./
drwxr-xr-x 21 root root 480 Sep 15 14:19 ../
drwx------ 2 systemd-resolve systemd-resolve 80 Sep 19 23:06 netif/
-rw-r--r-- 1 systemd-resolve systemd-resolve 714 Sep 19 23:06 resolv.conf
-rw-r--r-- 1 systemd-resolve systemd-resolve 783 Sep 19 23:06 stub-resolv.conf
-rw------- 1 root root 783 Sep 19 19:31 stub-resolv.conf.pppd-backup.ppp0
-rw-r--r-- 1 root root 805 Sep 19 23:06 stub-resolv.conf.tmp

Note how the stub-resolv.conf.pppd-backup-ppp0 has 0600 file permissions.

Now I stop the fortisslvpn VPN:

$ ls -al /run/systemd/resolve/
total 12
drwxr-xr-x 3 systemd-resolve systemd-resolve 120 Sep 19 23:06 ./
drwxr-xr-x 21 root root 480 Sep 15 14:19 ../
drwx------ 2 systemd-resolve systemd-resolve 60 Sep 19 23:06 netif/
-rw-r--r-- 1 systemd-resolve systemd-resolve 714 Sep 19 23:06 resolv.conf
-rw------- 1 root root 783 Sep 19 19:31 stub-resolv.conf
-rw-r--r-- 1 root root 805 Sep 19 23:06 stub-resolv.conf.tmp

Now the stub-resolv.conf file hs 0600 permissions and my DNS is broken.

[Dariusz Olszewski (dol-2a)]

I have a very similar problem when using a PPTP VPN.

I also have Ubuntu 18.04.1 LTS with the following packages installed:

network-manager 1.10.6-2ubuntu1.1
network-manager-config-connectivity-ubuntu 1.10.6-2ubuntu1.1
network-manager-gnome 1.8.10-2ubuntu1
network-manager-pptp 1.2.6-1
network-manager-pptp-gnome 1.2.6-1

systemd 237-3ubuntu10.9

Before connecting to the VPN I see the following permissions in the /run/systemd/resolve directory:

$ ls -l /run/systemd/resolve/
razem 12
drwx------ 2 systemd-resolve systemd-resolve 60 gru 13 23:03 netif
-rw-r--r-- 1 systemd-resolve systemd-resolve 609 gru 13 23:03 resolv.conf
-rw-r--r-- 1 systemd-resolve systemd-resolve 719 gru 13 23:03 stub-resolv.conf
-rw-r--r-- 1 root root 747 gru 13 22:58 stub-resolv.conf.tmp

I do not see any changes in permissions after connecting to the PPTP VPN.

However after disconnecting the VPN the permissions change as in the original bug report:

$ ls -l /run/systemd/resolve/
razem 12
drwx------ 2 systemd-resolve systemd-resolve 60 gru 13 23:23 netif
-rw-r--r-- 1 systemd-resolve systemd-resolve 681 gru 13 23:23 resolv.conf
-rw------- 1 root root 719 gru 13 23:03 stub-resolv.conf
-rw-r--r-- 1 root root 747 gru 13 23:23 stub-resolv.conf.tmp

With such permissions the DNS resolution process is broken.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Dariusz Olszewski (dol-2a)]

This might be a duplicate of: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1778946

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Paul Smith (psmith-gnu)]

I've had this happen to me with Ubuntu 18.10 as well.

[Marius Gedminas (mgedmin)]

I've the same problem with a L2TP VPN. This still happens on Ubuntu 19.10.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.