fix(run): refuse symlinked .git / .git/config for the config overlay - #111
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sbp-bvanb merged 2 commits intoSep 29, 2026
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The container-only .git/config overlay was built with [ -f ] and cp, which both follow symlinks. Workspaces are writable from the container, so the overlay step must not follow links out of the workspace. Overlay only when .git is a real directory and .git/config a regular file, neither a symlink. Adds tests/test_git_config_overlay.py, which runs the real run.sh against a stub runtime, and the archived OpenSpec change with the synced multi-workspace-mounts spec. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
stefanwb
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Thanks Joeri, this closes a real hole in something the threat model lists as protected, with a small fix. The new test runs in CI's unittest step. Approving.
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What
The container-only
.git/configoverlay inrun.shis now built only when.gitis a real directory and.git/configa regular file — neither may be a symlink.run.shruns host-side, and[ -f ]/cpfollow symlinks. The workspace is writable from the container, so a.gitor.git/configsymlink planted during one session made the next launch copy the link's host-side target into the stage dir and mount it into the container — a read of a host file outside the passed workspaces, which the threat model lists as protected.run.sh: symlink checks on both.gitand.git/config.tests/test_git_config_overlay.py: stdlib test that runs the realrun.shagainst a fakedockerrecording its argv; covers a real repo, a symlinked.git, and a symlinked.git/config.refuse-symlinked-git-config(archived;multi-workspace-mountsgains a scenario).Testing
python3 -m unittest discover -s tests -p 'test_*.py': 117 pass. The new test fails 2 of 3 cases againstmain'srun.sh.shellcheck -S warning run.sh: clean.openspec validate refuse-symlinked-git-config --strict: passes.run.shchange only.Touches the same loop and generated spec as the
.git/hooksread-only PR; whichever lands second needs a trivial rebase (keep both spec sections).🤖 Generated with Claude Code