2026.3.0.5 – closing an embedded RDP tab leaves the TCP connection open; the server session stays Active and its processes stall
2026.3.0.5 – closing an embedded RDP tab leaves the TCP connection open; the server session stays Active and its processes stall
SUMMARY
When an embedded RDP session tab is closed in Remote Desktop Manager for Linux, RDM does not
close the TCP connection to the server. The socket stays ESTABLISHED and RDM stops reading it.
The server therefore never sees a disconnect: the session remains "Active". A few minutes later
every process in that session stops running until the session is really disconnected.
For us this pauses a 24/7 application that runs in the interactive session on the server.
ENVIRONMENT
- Remote Desktop Manager for Linux 2026.3.0.5 (deb, amd64)
- Ubuntu 24.04.5 LTS, GNOME on Wayland, kernel 7.0.0-28-generic
- Session type: RDP, display mode: Embedded (tabbed)
- Server: Windows Server 2016 Standard (10.0.14393), direct connection to port 3389, no gateway
- Version 2025.3.0.8 was installed until 25 Sep 2026; we suspect the same behaviour there
(similar incidents, not measured)
STEPS TO REPRODUCE
1. Open an RDP session to a Windows server in an embedded tab and log on.
2. Close the tab (do not log off, do not use Start > Disconnect).
3. On the client: ss -tnpi '( dport = :3389 )'
4. On the server, from another session: quser
ACTUAL RESULT
Client:
- The socket is still owned by RemoteDesktopManager and stays in ESTAB.
- Recv-Q only grows, so RDM no longer reads it. One connection sampled after the tab was closed:
Recv-Q 0 -> 2322 -> 2475 -> 2577 -> 2730 -> ... -> 5025 -> 7983 -> 8136, state ESTAB all the time.
- When the server side is disconnected later, the socket goes to CLOSE-WAIT and stays there:
RDM never closes its end.
Server:
- quser keeps showing the session as Active, not Disc. No disconnect is logged.
- 2 to 4.5 minutes after the tab was closed (2:00, about 2:30, 3:25 and 4:27 in four runs; in a
fifth run nothing happened within 5:47) all processes of that session stop: their CPU time no
longer increases, GUI and console processes alike. About every 2 minutes they run for a moment
and stop again. Processes in session 0 are not affected.
- It also happens in a freshly created session.
- The stall ends within a second when the session is really disconnected: "tsdiscon <id>" from
another session, or the "time limit for active but idle sessions" policy, or a reconnect.
The same processes simply continue.
EXPECTED RESULT
Closing the tab disconnects the RDP session and closes the TCP connection, as closing the window
of mstsc or xfreerdp does. The server then shows the session as Disc.
IMPACT
After an administrator closes an RDM tab, the application running in that server session is
frozen for minutes, until somebody reconnects. On servers where that application must run around
the clock this is an outage.
WORKAROUNDS WE USE
- Start > Disconnect inside the session before closing the tab.
- Server side: the idle-session limit policy, which disconnects the stuck session after the limit.
QUESTIONS
1. Is this a known issue in RDM for Linux?
2. Is closing an embedded RDP tab meant to disconnect the session and close the socket?
3. Is there a setting that influences this?
4. Which logs would help? We can provide full "ss -tnpi" snapshots over time, the server-side
session events, and RDM logs if you tell us how to enable the relevant ones.
All Comments (4)
UP: 2026.3.1.1 64bit has same described issue
Hello,
Thank you for the very detailed report. Your measurements and reproduction steps made this much easier to investigate.
I was able to partially reproduce the issue in our lab, but not exactly as you described. I connected to a test VM from Remote Desktop Manager for Linux and closed the embedded tab without logging off or disconnecting. After that, I couldn’t connect to that VM from another computer. This suggests the VM still considered the Linux machine connected after the tab was closed, which matches what you saw: the session was never disconnected.
To answer your questions:
- Is this a known issue? We had no existing report of this behavior. I’ve passed your findings and my test results to our QA team so they can investigate further and log it with the development team.
- Is closing an embedded tab meant to disconnect the session? Yes. Closing the tab should disconnect the RDP session and close the connection, just like closing the mstsc or xfreerdp window.
- Is there a setting that influences this? We’re not aware of any setting in RDM that changes this behavior.
- Which logs would help? I’ll let you know if the team needs anything else.
Until this is fixed, the workarounds you’re already using are the right ones:
- Use Start > Disconnect inside the session before closing the tab.
- On the server, keep the “Set time limit for active but idle Remote Desktop Services sessions” policy, so a stuck session gets disconnected automatically.
I’ll keep you updated as soon as I hear back from the team.
Best regards,
Carl Marien
Thank you for the reply. Waiting how it's going on
Hello,
Thank you for the very detailed report. Your measurements and reproduction steps made this much easier to investigate.
I reproduced the issue in our lab. I connected to a test server from Remote Desktop Manager for Linux in an embedded tab and closed the tab without logging off or disconnecting. The server kept showing the session as Active instead of Disconnected, and the processes in that session stopped running until the session was reconnected.
To answer your questions:
- Is this a known issue? We had no existing report of this behavior. I’ve passed your findings and my reproduction to our QA team, and they’ll log it with the development team.
- Is closing an embedded tab meant to disconnect the session? Yes. Closing the tab should disconnect the RDP session and close the connection, just like closing the mstsc or xfreerdp window.
- Is there a setting that influences this? Im not aware of any setting in RDM that changes this behavior.
- Which logs would help? I’ll let you know if the team needs anything else.
Until this is fixed, the workarounds you’re already using are the right ones:
- Use Start > Disconnect inside the session before closing the tab.
- On the server, keep the “Set time limit for active but idle Remote Desktop Services sessions” policy, so a stuck session gets disconnected automatically.
I’ll keep you updated on the progress of this issue.
Best regards,
Carl Marien