openssh bugs - Nov 2025 - [Bug 3890] New: SSH with a control path and -tt hangs waiting for user input.

https://bugzilla.mindrot.org/show_bug.cgi?id=3890

            Bug ID: 3890
           Summary: SSH with a control path and -tt hangs waiting for user
                    input.
           Product: Portable OpenSSH
           Version: 10.1p1
          Hardware: Other
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P5
         Component: ssh
          Assignee: unassigned-bugs at mindrot.org
          Reporter: jacobenders1 at gmail.com

Hello, I've been trying to debug why my SSH connections keep hanging. I
recently upgraded my NIXOS system to latest packages, and now my
scripts are broken.

I've nailed it down to it likely being an SSH issue. I don't know if
this change was intentional or not. But it's a breaking change.

Below are 3 commands that I expect to all behave kinda the same. The
third command here is causing scripts to hang because it seems to be
waiting for user input. I need to press two buttons on my keyboard and
then it will resume. Something with the ControlFile is being weird.

FIRST COMMAND (GOOD): (NO CONTROL PATH)

ssh yapms.com -o ControlMaster=auto -o
'ControlPath="/home/jacob/bad"'
-o 'User="yapms"' -o ControlPersist=60s 'bash
dothing.sh'

OUTPUT> HELLO THERE!!!


SECOND COMMAND (GOOD): (NO CONTROL PATH)
ssh -o ControlMaster=auto -o ControlPersist=60s -o
'IdentityFile="/home/jacob/.ssh/ansible_rsa"' -o
'User="yapms"' -tt
74.208.201.82 'bash dothing.sh'

OUTPUT> HELLO THERE!!!
OUTPUT> Connection to 74.208.201.82 closed.


THIRD COMMAND (BAD): (HAS CONTROL PATH)

ssh -o ControlMaster=auto -o ControlPersist=60s -o
'ControlPath="/home/jacob/bad"' -o
'IdentityFile="/home/jacob/.ssh/ansible_rsa"' -o
'User="yapms"' -tt
74.208.201.82 'bash dothing.sh'

*hangs until I press two keys on my keyboard*

OUTPUT> HELLO THERE!!!
OUTPUT> Shared connection to 74.208.201.82 closed.

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--- Comment #1 from Jacob Enders <jacobenders1 at gmail.com> ---
Sorry, here is one more example. It has a control path, but it uses my
ssh config for yapms.com. Without the -tt. This works even with a
control path.

FOURTH COMMAND (GOOD): (HAS CONTROL PATH)

ssh yapms.com -o ControlMaster=auto -o ControlPersist=60s -o
'ControlPath="/home/jacob/bad"' -o
'IdentityFile="/home/jacob/.ssh/ansible_rsa"' -o
'User="yapms"' 'bash
dothing.sh'

OUTPUT> HELLO THERE!!!

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Darren Tucker <dtucker at dtucker.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dtucker at dtucker.net

--- Comment #2 from Darren Tucker <dtucker at dtucker.net> ---
This is the main reason 10.2 was out quickly.  You want this patch:

https://github.com/openssh/openssh-portable/commit/beae06f56e0d0a66ca535896149d5fb0b2e8a1b4

or update to 10.2:

Changes since OpenSSH 10.1
=========================
This is a bugfix release, primarily to fix a problem that rendered
ssh(1) unusable when ControlPersist was enabled.

Bugfixes
--------

 * ssh(1): fix mishandling of terminal connections when
   ControlPersist was active that rendered the session unusable.
   bz3872

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Darren Tucker <dtucker at dtucker.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|NEW                         |RESOLVED

--- Comment #3 from Darren Tucker <dtucker at dtucker.net> ---


*** This bug has been marked as a duplicate of bug 3872 ***

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