Bug 1412468
| Summary: | vncserver errors when starting under selinux following the draft Fedora 25 system administrators guide | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Neil Squires <neil> |
| Component: | tigervnc | Assignee: | Jan Grulich <jgrulich> |
| Status: | CLOSED EOL | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | low | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 25 | CC: | accounts, alessandro.suardi, bphinz, jgrulich, khua, markus.hillig, twaugh |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-12-12 10:07:19 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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Description
Neil Squires
2017-01-12 05:44:43 UTC
A copy of the selinux permissions from the users home directory # ls -laZ /home/nfsquires/.vnc* total 20 drwxrwxr-x. 2 nfsquires nfsquires unconfined_u:object_r:user_home_t:s0 112 Jan 12 15:40 . drwx------. 3 nfsquires nfsquires unconfined_u:object_r:user_home_dir_t:s0 114 Jan 12 15:40 .. -rw-r--r--. 1 nfsquires nfsquires system_u:object_r:user_home_t:s0 332 Jan 12 13:17 config -rw-------. 1 nfsquires nfsquires unconfined_u:object_r:user_home_t:s0 8 Jan 12 13:16 passwd -rw-r--r--. 1 nfsquires nfsquires system_u:object_r:user_home_t:s0 616 Jan 12 15:40 vpn.squires.id.au:1.log -rw-r--r--. 1 nfsquires nfsquires system_u:object_r:user_home_t:s0 5 Jan 12 15:40 vpn.squires.id.au:1.pid -rwxr-xr-x. 1 nfsquires nfsquires system_u:object_r:user_home_t:s0 92 Jan 12 13:17 xstartup With setenforce 1 and restarting the service Jan 12 17:53:42 vpn.squires.id.au systemd[1]: Stopping Remote desktop service (VNC)... -- Subject: Unit vncserver@:1.service has begun shutting down -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit vncserver@:1.service has begun shutting down. Jan 12 17:53:42 vpn.squires.id.au vncserver[4436]: Killing Xvnc process ID 4378 Jan 12 17:53:42 vpn.squires.id.au audit[1]: AVC avc: denied { read } for pid=1 comm="systemd" name="vpn.squires.id.au:1.pid" dev="dm-0" ino=25247161 scontext=system_u:system_r:init_t:s0 tcontext=system_u: Jan 12 17:53:43 vpn.squires.id.au systemd[1]: Stopped Remote desktop service (VNC). -- Subject: Unit vncserver@:1.service has finished shutting down -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit vncserver@:1.service has finished shutting down. Jan 12 17:53:43 vpn.squires.id.au audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=vncserver@:1 comm="systemd" exe="/usr/lib/systemd/systemd" hostn Jan 12 17:53:43 vpn.squires.id.au systemd[1]: Starting Remote desktop service (VNC)... -- Subject: Unit vncserver@:1.service has begun start-up -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit vncserver@:1.service has begun starting up. Jan 12 17:53:43 vpn.squires.id.au vncserver[4447]: Can't find file /home/nfsquires/.vnc/vpn.squires.id.au:1.pid Jan 12 17:53:43 vpn.squires.id.au vncserver[4447]: You'll have to kill the Xvnc process manually Jan 12 17:53:46 vpn.squires.id.au vncserver[4451]: New 'vpn.squires.id.au:1 (nfsquires)' desktop is vpn.squires.id.au:1 Jan 12 17:53:46 vpn.squires.id.au vncserver[4451]: Starting applications specified in /home/nfsquires/.vnc/xstartup Jan 12 17:53:46 vpn.squires.id.au vncserver[4451]: Log file is /home/nfsquires/.vnc/vpn.squires.id.au:1.log Jan 12 17:53:46 vpn.squires.id.au audit[1]: AVC avc: denied { read } for pid=1 comm="systemd" name="vpn.squires.id.au:1.pid" dev="dm-0" ino=25247160 scontext=system_u:system_r:init_t:s0 tcontext=system_u: Jan 12 17:53:46 vpn.squires.id.au audit[1]: AVC avc: denied { read } for pid=1 comm="systemd" name="vpn.squires.id.au:1.pid" dev="dm-0" ino=25247160 scontext=system_u:system_r:init_t:s0 tcontext=system_u: Jan 12 17:53:46 vpn.squires.id.au audit[1]: AVC avc: denied { read } for pid=1 comm="systemd" name="vpn.squires.id.au:1.pid" dev="dm-0" ino=25247160 scontext=system_u:system_r:init_t:s0 tcontext=system_u: Jan 12 17:53:46 vpn.squires.id.au systemd[1]: vncserver@:1.service: PID file /home/nfsquires/.vnc/vpn.squires.id.au:1.pid not readable (yet?) after start: Permission denied Jan 12 17:53:47 vpn.squires.id.au dbus-daemon[4475]: [session uid=1000 pid=4473] Activating service name='org.freedesktop.systemd1' requested by ':1.0' (uid=1000 pid=4477 comm="systemctl --user import-enviro Jan 12 17:53:47 vpn.squires.id.au dbus-daemon[4475]: [session uid=1000 pid=4473] Activated service 'org.freedesktop.systemd1' failed: Process org.freedesktop.systemd1 exited with status 1 Jan 12 17:55:14 vpn.squires.id.au systemd[1]: vncserver@:1.service: Start operation timed out. Terminating. Jan 12 17:55:17 vpn.squires.id.au audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=vncserver@:1 comm="systemd" exe="/usr/lib/systemd/systemd" host Jan 12 17:55:17 vpn.squires.id.au audit[1]: AVC avc: denied { unlink } for pid=1 comm="systemd" name="vpn.squires.id.au:1.pid" dev="dm-0" ino=25247160 scontext=system_u:system_r:init_t:s0 tcontext=system_ Jan 12 17:55:17 vpn.squires.id.au systemd[1]: Failed to start Remote desktop service (VNC). -- Subject: Unit vncserver@:1.service has failed -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit vncserver@:1.service has failed. -- -- The result is failed. Jan 12 17:55:17 vpn.squires.id.au systemd[1]: vncserver@:1.service: Unit entered failed state. Jan 12 17:55:17 vpn.squires.id.au systemd[1]: vncserver@:1.service: Failed with result 'timeout'. After installing the selinux tools, I ran # ausearch -c 'systemd' --raw | audit2allow -M my-systemd The result .te was module my-systemd 1.0; require { type init_t; type unconfined_service_t; type user_home_t; type admin_home_t; class unix_stream_socket create; class file { open read unlink }; } #============= init_t ============== allow init_t admin_home_t:file { read unlink }; allow init_t unconfined_service_t:unix_stream_socket create; allow init_t user_home_t:file { open read unlink }; I installed the resultant my-systemd.pp # semodule -i my-systemd.pp dropped back to the user and started the vncserver $ sudo systemctl restart vncserver@:1.service The service started. I was able to get vncserver properly start vi systemd after applying Neil's semodule. However, I also had to add "Environment=XDG_SESSION_TYPE=x11" to the [Service]. If I didn't add the environment variable, all I got was a black screen. Fedora 26 here (coming from successful upgrades since F22 IIRC), vncserver worked fine until I moved from nouveau to NVidia drivers to avoid overheating of my Aspire Revo R3600 GPU. XFCE4 desktop.
Black screen for vncserver upon reboot, as in Kent's comment.
Originally files in ~/.vnc for my user mislabeled as root_home_t - restorecon -R of ~/.vnc brings them back to user_home_t. Still black screen.
Mini-semodule solution, as in Neil's example, to address missing read permissions on vncserver .pid file:
module my-systemd 1.0;
require {
type user_home_t;
type init_t;
class file { read unlink };
}
#============= init_t ==============
allow init_t user_home_t:file { read unlink };
And that fixed it for me - no need to add XDG_SESSION_TYPE=x11 (I would have had to look up where to add that entry, as I don't know where it should go).
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