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GeezerVison is showing github.com — Fix for Linux platform PowerShell exit on error during SSH remoting connection by PaulHigin · Pull Request #4993 · PowerShell/PowerShell

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@PaulHigin

@PaulHigin Paul Higinbotham (PaulHigin) commented Oct 3, 2017

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This fixes addresses issue #4940.

The problem is that the connection clean up code in SSHClientSessionTransportManager would try to terminate a process with id == 0, which is the initial value for the _sshProcessId field when no SSH process has been created yet. For both Linux and Windows platforms process id of zero is a special process and should not be terminated. Fortunately those processes are not terminated by the existing code but on Linux platforms the PowerShell parent process exits immediately.

The fix is to add checks that the SSH process has been created and is valid before terminating it during connection cleanup.

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@PaulHigin
Fix for Linux platform PowerShell exit on error during SSH remoting c…
2695e00 
…onnection
@PaulHigin Paul Higinbotham (PaulHigin) added WG-Remoting PSRP issues with any transport layer Issue-Bug Issue has been identified as a bug in the product OS-Linux OS-macOS labels Oct 3, 2017
@PaulHigin Paul Higinbotham (PaulHigin) added this to the 6.0.0-HighPriority milestone Oct 3, 2017
@PaulHigin Paul Higinbotham (PaulHigin) assigned Mike Richmond (mirichmo) Oct 3, 2017
@PaulHigin
Paul Higinbotham (PaulHigin) requested a review from Steve Lee (SteveL-MSFT) October 3, 2017 18:21
@PaulHigin
Paul Higinbotham (PaulHigin) requested review from Dan Travison (dantraMSFT) and Mike Richmond (mirichmo) as code owners October 3, 2017 18:21
dantraMSFT
Dan Travison (dantraMSFT) approved these changes Oct 3, 2017
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@dantraMSFT Dan Travison (dantraMSFT) left a comment •
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LGTM

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SteveL-MSFT
Steve Lee (SteveL-MSFT) requested changes Oct 3, 2017
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Comment thread src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs
if (stdErrReader != null) { stdErrReader.Dispose(); }

try
var sshProcessId = _sshProcessId;

@SteveL-MSFT Steve Lee (SteveL-MSFT) Oct 3, 2017

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Can't you use _sshProcessId directly instead of creating a new variable?

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@PaulHigin Paul Higinbotham (PaulHigin) Oct 3, 2017

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CloseConnection can be called from multiple places (state machine, error handling) and this is just to prevent going through this code path multiple times. I am not concerned about race conditions since Process type is thread safe ... I just want to prevent running the code path after the process has been terminated.

I'll add a comment to clarify.

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Comment thread src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs

try
var sshProcessId = _sshProcessId;
_sshProcessId = 0;

@SteveL-MSFT Steve Lee (SteveL-MSFT) Oct 3, 2017

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Perhaps initialize it to 0 in the constructor instead of resetting it here?

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@PaulHigin Paul Higinbotham (PaulHigin) Oct 3, 2017

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CLR guarantees all fields are initialized to zero. I am setting it back to zero here to prevent the code path running twice (see comment above).

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@PaulHigin
Added comment for clarification per code review request
6ff7c85
SteveL-MSFT
Steve Lee (SteveL-MSFT) approved these changes Oct 3, 2017
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mirichmo
Mike Richmond (mirichmo) approved these changes Oct 4, 2017
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@mirichmo
Mike Richmond (mirichmo) merged commit 5b54e4d into PowerShell:master Oct 4, 2017
@PaulHigin
Paul Higinbotham (PaulHigin) deleted the Fix-SSHRemoting-PowerShell-Exit branch October 4, 2017 15:15
@PaulHigin Paul Higinbotham (PaulHigin) mentioned this pull request Oct 4, 2017
PowerShell exits opening runspace created with SSHConnectionInfo #4940
Closed
Thatgfsj (Thatgfsj) pushed a commit to Thatgfsj-contribs/PowerShell that referenced this pull request Aug 6, 2026
@PaulHigin @mirichmo
Fix for Linux platform PowerShell exit on error during SSH remoting c…
07e45ca 
…onnection (PowerShell#4993)

* Fix for Linux platform PowerShell exit on error during SSH remoting connection

* Added comment for clarification per code review request
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Reviewers

@SteveL-MSFT Steve Lee (SteveL-MSFT) SteveL-MSFT approved these changes
+2 more reviewers
@dantraMSFT Dan Travison (dantraMSFT) dantraMSFT approved these changes
@mirichmo Mike Richmond (mirichmo) mirichmo approved these changes
Reviewers whose approvals may not affect merge requirements

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@mirichmo Mike Richmond (mirichmo)

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Issue-Bug Issue has been identified as a bug in the product OS-Linux OS-macOS WG-Remoting PSRP issues with any transport layer

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6.0.0-GA

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4 participants

@PaulHigin @SteveL-MSFT @dantraMSFT @mirichmo
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