Codex round 3 found two more bypasses of the public-root guard,
both specific to the all-in-one image (Dockerfile.aio):
- /app/frontend/dist (FRONTEND_DIR) ships nodejs-owned and is
served unauthenticated as the built SPA -- missing from the
protected-roots list.
- /app/storage is a symlink to /data/storage (the actual
STORAGE_PATH). A destination given as /app/storage/uploads/logos
passed the guard's lexical path.resolve() comparison while
resolving, on disk, to the exact same directory as the protected
STORAGE_PATH/uploads/logos. isUnderPubliclyServableRoot now
resolves symlinks in whatever prefix of each path already
exists (resolveRealish) before comparing, rather than relying on
path.resolve() alone.
Also restores three fs.mkdir spies in the test file that were
never un-spied, which silently leaked a rejected mock into any
later test doing a real fs.mkdir -- exactly what the new symlink
test needed to set up its fixture.
Found by codex review, round 3.
Paul Nothaft
4bb0210a2b