Child processes is NOT killed on disconnect

[goranschwarz]

"OpenSSH for Windows" version
7.7.2.3

Server OperatingSystem
Windows 10 Pro (just for testing)

Client OperatingSystem
Any ssh client, Linux or Windows

What is failing
When disconnecting (killing the client) from the SSH Server, the process continues to execute on the server side

Expected output
(on Linux) Processes stared by the server process (sshd) will be terminated on the server side when a connection is lost

Actual output
The started process (in this case typeperf ...) is continuing to run (causing many server processes, since the client connection (which actually is a monitor server), just reconnects and issues the same command again)

repro example

• open a "dos prompt" on the local machine (cmd)
• ssh username@127.0.0.1 typeperf -si 3 "\Processor(*)\*"
• then kill the "dos prompt" by clicking the "x" to kill/close the window
• Task manager still shows that the typeperf -si 3 ... is running

[goranschwarz]

Just tested with latest SSHD version: 8.1.0.0
(no change) same behavior as above...

[bagajjal]

@goranschwarz - I'm able to repro the issue.
For now use "ssh -t user@ip " which kills the child processes.
We added JOB_OBJECT_LIMIT_BREAKAWAY_OK flag so that child processes with CREATE_BREAKAWAY_FROM_JOB flag can run for long time even if the ssh connection dies. This is a specific ask as we want the long running processes continue to run irrespective of ssh connection.

Even though the code path between pty, no-pty is same. The behavior is different. I will debug this further.

[goranschwarz]

@bagajjal Is this fixed in V8.6.0.0 ???

[bagajjal]

@goranschwarz - No, it's not fixed in v8.6.

[goranschwarz]

@bagajjal Ok, do you have a "estimated" release... 1 month, 6 month, 1 year... or longer ???

[bagajjal]

@goranschwarz , It will be fixed in the next release, probably before 2021 year end.

[goranschwarz]

@bagajjal Thanx :)

[DentalDecisionS]

any update on this issue? This is a bug the windows server gets bogged down by hundreds of child processes running without being terminated even after the session is closed.