PR #17776: fix(ssh): pass --no-overwrite-dir to tar extract to prevent clobbering directory modes

• Repository: NousResearch/hermes-agent
• Author: luyao618
• State: closed | merged: False
• Link: https://github.com/NousResearch/hermes-agent/pull/17776

Description (problem / solution / changelog)

Summary

Fixes #17767

The SSH bulk upload (_ssh_bulk_upload in tools/environments/ssh.py) pipes a tar archive into tar xf - -C / on the remote host. GNU tar's default behaviour overwrites existing directory metadata with what is in the archive. When the local umask produces group-writable dirs (0775, common on Ubuntu with umask 002), intermediate directories like the user's home (/home/<user>) get their mode overwritten to 0775. This causes OpenSSH StrictModes to reject ~/.ssh/authorized_keys, silently locking the user out of SSH with Permission denied (publickey).

Changes

• tools/environments/ssh.py:185: Added --no-overwrite-dir flag to the remote tar xf invocation. This preserves the metadata of directories that already exist on the remote while still extracting all file content correctly. New directories created by tar still get reasonable modes via the remote umask.
• tests/tools/test_ssh_bulk_upload.py: Updated assertion to match the new tar command.

Testing

• All existing SSH environment tests pass (34 passed, 11 skipped).
• The fix is a single flag addition to a shell command — minimal risk of regression.

Linked Issue

Closes #17767

Changed files

• tests/tools/test_ssh_bulk_upload.py (modified, +1/-1)
• tools/environments/ssh.py (modified, +1/-1)

PR #17867: fix(ssh): prevent tar from overwriting remote home dir permissions (#17767)

• Repository: NousResearch/hermes-agent
• Author: vominh1919
• State: closed | merged: True
• Link: https://github.com/NousResearch/hermes-agent/pull/17867

Description (problem / solution / changelog)

Summary

The SSH terminal backend's _ssh_bulk_upload() uses tar xf - -C / to extract files to the remote root. GNU tar's default behavior overwrites the metadata (including mode) of existing directories. When the local umask is 002 (Ubuntu default), staging directories are created with 0775 mode, and tar overwrites /home/<user> to 0775.

This breaks OpenSSH's StrictModes yes (default), which requires the home directory to NOT be group-writable. Subsequent SSH connections fail with Permission denied (publickey).

Fix

Add --no-overwrite-dir to the remote tar command:

# Before
tar xf - -C /

# After
tar xf - --no-overwrite-dir -C /

--no-overwrite-dir tells tar to skip updating the attributes of already-existing directories, preserving the remote system's correct 0755 mode.

Impact

• Fixes SSH authentication breakage after first file sync
• No functional change to file extraction — files are still written correctly
• Only directory metadata preservation changes

Fixes #17767

Changed files

• tools/environments/ssh.py (modified, +5/-1)

PR #17898: fix(ssh): prevent tar from overwriting remote home dir permissions (#17767)

• Repository: NousResearch/hermes-agent
• Author: teknium1
• State: closed | merged: True
• Link: https://github.com/NousResearch/hermes-agent/pull/17898

Description (problem / solution / changelog)

Salvages #17867 by @vominh1919 onto current main. Closes #17767.

Problem

The SSH terminal backend's _ssh_bulk_upload() runs tar xf - -C / on the remote, extracting a staging directory tree to the remote root. GNU tar's default is to overwrite metadata (including mode) of existing directories. When the local umask is 002 (Ubuntu default), staging dirs are 0775, and tar chmods /home/<user> to 0775 on the remote.

That violates sshd StrictModes yes (which requires non-group-writable home dirs), so subsequent SSH connections fail with Permission denied (publickey). Recovery requires out-of-band console access to chmod the home dir back. Reporter (@luismartinezs) hit this on a Hetzner VPS and couldn't reconnect.

Confirmed on current main — tools/environments/ssh.py:185 still has the bare tar xf - -C /.

Fix (author: @vominh1919, 1 file, +5/-1)

Add --no-overwrite-dir to the remote tar command. Tar skips updating attributes of already-existing directories, so new entries (~/.hermes/, ~/.hermes/skills/) are still created with reasonable modes via remote umask, but /home/<user> keeps its original 0755.

Follow-up test update

tests/tools/test_ssh_bulk_upload.py::test_tar_pipe_commands asserted the literal substring "tar xf - -C /" in the ssh command — which is no longer present with --no-overwrite-dir between tar xf - and -C /. Split into three separate assertions; added an explicit check for the new flag as a regression guard.

Validation

scripts/run_tests.sh tests/tools/test_ssh_bulk_upload.py tests/tools/test_ssh_environment.py
34 passed, 11 skipped

Authorship preserved for @vominh1919 via plain cherry-pick.

Changed files

• tests/tools/test_ssh_bulk_upload.py (modified, +4/-2)
• tools/environments/ssh.py (modified, +5/-1)