Four corrections noted by the test plan's executor in commit 461b8d0:
- PID-lookup race: pgrep+head can pick the wrong instance. Replace
with systemctl show -p MainPID --value left4me-server@N.service.
- gdb-from-host ptrace check: nsenter into only the mount namespace
with root caps bypasses the SECCOMP filter, so the test is a false
positive. Replace with systemd-run-with-same-directives probe, or
syscall-filter inspection.
- D5 pgrep pattern: 'srcds_linux.*\@2' doesn't match because @N is
in the unit name, not argv. Use systemctl show -p MainPID.
- scmp_sys_resolver is in the seccomp package on Debian 13, not
libseccomp-dev.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Ran the 11-test plan against left4me-server@1 (canary) and left4me-web
on left4.me / Debian 13 / systemd 257. Cleaned up all unit drop-ins;
kept the Test 9 sysctl (kernel.yama.ptrace_scope=2) per spec.
Outcomes:
- server@1 systemd-analyze: 7.5 EXPOSED → 1.3 OK
- left4me-web systemd-analyze: 8.7 EXPOSED → 4.1 OK
- All 8 attack vectors in Test 8 (D1.a-c, D2.a-c, D3, D5) blocked
- Test 6 (MemoryDenyWriteExecute) fails as predicted — Source engine
i386 .so files have text relocations; exclude from final composition.
- Test 11 (24-48h soak) skipped per operator decision.
Two amendments to the spec's proposed composition required for the
refactor:
- SystemCallArchitectures=native x86 (not bare 'native') — srcds_linux
is i386, the kernel kills every native-only call.
- PrivatePIDs=true added — ProtectProc=invisible alone cannot hide
gunicorn from srcds because both run as uid 980; PrivatePIDs gives
each instance its own PID namespace and closes D2.b.
Spec bugs surfaced and documented in the "Output" section: PID lookup
via pgrep (race vs. instance), Test 4/10 gdb-from-host doesn't
actually exercise the unit's SECCOMP filter, Test 8 D5 pgrep pattern
won't match. Tooling note corrected: scmp_sys_resolver is in
'seccomp' package, not 'libseccomp-dev'.
Next session: write docs/superpowers/plans/2026-MM-DD-hardening-refactor.md
against the proven composition; supersede the uid-split spec.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Reframe the queued uid-split decision into a broader hardening analysis.
Audit found the same-uid attack surface (DB readable from srcds, ptrace
allowed, RCON stored plaintext) is closable by either uid split or
systemd directive composition; the three specs ground that choice in a
threat model, survey the defenses, and lay out a self-contained test
plan to run on left4.me next. uid-split spec deferred pending results.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
