Automated security review (HIGH) caught a jail-escape my own review
missed: copy_recursive used fs::metadata (follows symlinks). A symlink
inside the jail pointing to e.g. /etc, then a 'copy' of its parent dir,
would dereference it and pull external content INTO the jail where it
could be read — a read-escape exfiltration. jail() validates only the
top-level src/dest; the recursive walk reintroduced the escape.
Fix: copy_recursive uses symlink_metadata and refuses any symlink
('symlinks are not followed across the jail boundary'). list() likewise
switched to symlink_metadata so it reports the link, never the
dereferenced target's size/type (info leak). Two regression tests added:
copy-symlink-exfil (asserts no external content lands inside) and
list-no-deref. 44/44 tests green. Rolled forward to alpha.4 (vulnerable
alpha.3 superseded).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
steam_update func runs SteamCMD per game (rust/conan/soulmask app-ids;
dune rejected), streaming stdout to {instance}.steam_status. Jailed
file manager on {instance}.files.cmd: list/read/write/delete/rename/
mkdir/mkfile/move/copy, all confined to instance root via two-stage
lexical-normalize + canonicalize (defeats ../ traversal AND symlink
escape — incl chained symlinks). Replaces the Go agent's UNJAILED
legacy files API (retired, not ported). 5MiB read cap.
42/42 tests green: 24 filemanager incl 7 jail-escape attempts
(dotdot, deep dotdot, absolute, symlink-inside, direct symlink,
chained symlink), 5 steamcmd app-id (cfg-gated win/linux soulmask).
Jail logic reviewed line-by-line: Path::starts_with is component-wise
(no sibling-prefix bypass), non-existent suffix components can't be
symlinks, leading .. normalizes to / and fails the prefix check.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
