SSH session does not correctly release file handles after closing

Prerequisites

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Steps to reproduce

After establishing a connection, my SSH client reuses this connection and creates a session every second over this connection, sending an exec command on ssh channel to execute some simple script commands, and then closes this session. After my client program ran continuously for about 20 days, my Windows machine hung due to exhausted memory. Analysis revealed that the sshd process had a large number of handles that were not correctly released, as well as a significant number of residual cmd.exe processes.

I tried upgrading to version v9.2.2.0p1-Beta, but the issue still persists. However, after switching to the Bitvise SSH Server software, this problem no longer occurred. As a comparison, the same logic works as expected when running on Linux and macOS servers. I believe this should be a relatively easy case to reproduce, so I won't go into further details.

Expected behavior

no leaks

Actual behavior

file handlers leak

Error details

No response

Environment data

Name                           Value
----                           -----
PSVersion                      5.1.22621.1778
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.22621.1778
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

Version

8.6p1

Visuals

too many file handlers hold by sshd.exe

about 2000000 cmd.exe processes, all 32K page table used