Tigervnc killed just after connect

[zaferarican]

Describe the bug
When I try to a tigervnc session, it displays the password dialog, I type and just after typing I get connection refused. When I check session I see that the pid is stale.

To Reproduce
Steps to reproduce the behavior:

1. Connect to machine with a client
2. Type password (it is true password)
   3.It displays connection refused.

Expected behavior
It should connect but it does not

Client (please complete the following information):

• OS: iOS
• VNC client: Jump Desktop App

Server (please complete the following information):

• OS: Debian Unstable - aarch64
• VNC server: Tiger VNC
• VNC server version: 1.9.0
• Server downloaded from: Debian
• Server was started using: 'vncserver :2 -localhost no'

Additional context
Log output:

Xvnc TigerVNC 1.9.0 - built Dec 1 2018 21:51:29
Copyright (C) 1999-2018 TigerVNC Team and many others (see README.rst)
See http://www.tigervnc.org for information on TigerVNC.
Underlying X server release 12003000, The X.Org Foundation

Sun Mar 3 16:48:07 2019
vncext: VNC extension running!
vncext: Listening for VNC connections on all interface(s), port 5902
vncext: created VNC server for screen 0
** Message: 16:48:07.653: main.vala:101: Session is LXDE
** Message: 16:48:07.653: main.vala:102: DE is LXDE
** Message: 16:48:07.680: main.vala:133: log directory: /home/zafer/.cache/lxsession/LXDE
** Message: 16:48:07.681: main.vala:134: log path: /home/zafer/.cache/lxsession/LXDE/run.log

Sun Mar 3 16:48:17 2019
Connections: accepted: 172.xx.xx.xx::51699

Sun Mar 3 16:48:18 2019
SConnection: Client needs protocol version 3.8
SConnection: Client requests security type VncAuth(2)
terminate called after throwing an instance of 'rdr::Exception'
terminate called recursively
(EE)
(EE) Backtrace:
(EE) 0: /usr/bin/Xtigervnc (+0x1a8) [0x5565bad9d0]
(EE) unw_get_proc_info failed: no unwind info found [-10]
(EE)
(EE)
Fatal server error:
(EE) Caught signal 6 (Aborted). Server aborting
(EE)

xstartup file

#!/bin/sh
unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
unset DBUS_SESSION_MANAGER_ADDRESS
exec /usr/bin/startlxde&

[samhed]

Does it only happen with this "Jump Desktop App" client? Did you test any other VNC client?

[zaferarican]

I tried

• vncviewer for windows available in tigervnc.org. I got the same error.

I tried

• a vncviewer on linux. I got the same error

I tried

• "connect to server" in macOS from Finder->Go. I got the following error

Xvnc TigerVNC 1.9.0 - built Dec 1 2018 21:51:29
Copyright (C) 1999-2018 TigerVNC Team and many others (see README.rst)
See http://www.tigervnc.org for information on TigerVNC.
Underlying X server release 12003000, The X.Org Foundation

Wed Mar 6 13:50:01 2019
vncext: VNC extension running!
vncext: Listening for VNC connections on all interface(s), port 5901
vncext: created VNC server for screen 0
** Message: 13:50:01.866: main.vala:101: Session is LXDE
** Message: 13:50:01.867: main.vala:102: DE is LXDE
** Message: 13:50:01.898: main.vala:133: log directory: /home/zafer/.cache/lxsession/LXDE
** Message: 13:50:01.898: main.vala:134: log path: /home/zafer/.cache/lxsession/LXDE/run.log

Wed Mar 6 13:50:14 2019
Connections: accepted: 192.168.1.10::54683
SConnection: Client needs protocol version 3.3
terminate called after throwing an instance of 'rdr::EndOfStream'
terminate called recursively
(EE)
(EE) Backtrace:
(EE) 0: /usr/bin/Xtigervnc (OsLookupColor+0x1a8) [0x55745869d0]
(EE) unw_get_proc_info failed: no unwind info found [-10]
(EE)
(EE)
Fatal server error:
(EE) Caught signal 6 (Aborted). Server aborting
(EE)

[CendioOssman]

I'm afraid I can't really see in the code how this is possible. Do you think you could try building TigerVNC yourself using the code here on github? Perhaps Debian has patched something that is causing this.

[englishextra]

@zaferarican

I gave up with tigervnc server on fedora 28 and 29. TigerVNC is broken. This must be aknowledged.

[zaferarican]

I am trying to build tigervnc from source. It builds fine but it says

vncserver: couldn't find "/usr/local/bin/Xvnc"
Am I missing something?

[CendioOssman]

Maybe. :)

Using cmake and make builds the main parts of TigerVNC, but not Xvnc. That part is unfortunately a bit trickier. Please see the Building the TigerVNC Server on Modern Unix/Linux Systems section of BUILDING.txt. The call to configure may need to be tweaked depending on the version of Xorg used though, so we don't have any universal tips there.

[CendioOssman]

You could also try attaching gdb to the Xvnc process and see if it can give you more details about where it crashes.

[bernhardu]

Hello, I tried to collect some more information about this and attached it to the debian bug.
It looks like it is related to having no readonly password configured and contructor PlainPasswd
throwing an exception.

[CendioOssman]

Thank you for that extra debugging.

Unfortunately our code is without a doubt correct in that case. So it must be a bug in the system, which you've also concluded. As such, I'm afraid I'll be closing this bug without any action from us.

The crash on termination is actually known and was reported in #812. Fortunately it is fixed on master so it will be resolved in the next release.

[kadrim]

a workaround can be by starting the server like this:

For 64-Bit Arm

LD_PRELOAD=/lib/aarch64-linux-gnu/libgcc_s.so.1 vncserver :2 -localhost no

For 32-Bit Arm

LD_PRELOAD=/lib/arm-linux-gnueabihf/libgcc_s.so.1 vncserver :2 -localhost no

as described here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=932499