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4 Commits
Author SHA1 Message Date
Marius CiepluchandClaude Opus 5 fec67253f3 feat(model-grounded-detection): 4.1 guard dominance, 4.2 the missing sink facts
4.1 is the arbiter for the class no crash oracle reaches. An access-control bug
is the ABSENCE of a guard: no flow to follow, no crash to reproduce. What the
model can establish is a consistency violation -- an obligated operation no
discharging guard governs, in a file where its siblings are governed by one.

"Governed" turned out not to be one relation, and asking pure CFG dominance of
the operation gets two of three shapes wrong. Measured against the real engine:

  identity constraint  the guard is INSIDE the operation's arguments
                       filter_by(owner_id = current_user.id)
  identity branch      abort(403).controlledBy == [note.owner_id != current_user.id]
                       -- the check runs AFTER the fetch, so it never dominates
                       the operation, but it controls whether the value escapes
  dominating guard     a discharger-naming call that dominates the operation

That is why the query uses controlledBy rather than dominatedBy for shape 2.

Two bugs found by running it, both the same class as the sanitizer bug in group
2 -- part of a fact flattened, the part carrying the signal dropped:

  * dominance_specs used only `calls` and `decorators`, omitting
    identity_sources (current_user, request.user) and constraint_params
    (owner_id, user_id) -- which is how an identity constraint is actually
    written. The arbiter reported "no guard" on handlers that plainly had one.
    request_sources and permissive_values stay excluded: they describe the
    vulnerable shape, and including them would let the arbiter read a bug as
    its own fix.
  * matching operations by code containment yielded four or five desugared rows
    per operation (the bare `tmp1.filter_by` receiver among them, carrying none
    of the guards the real call has), so a guarded operation could be flagged.
    Matching is by call name now.

Live, deterministic, zero model calls:
  leaky      -> model_entailed  no discharging guard, while 2 sibling handlers are guarded
  edit_note  -> no finding      (ownership check controls the denial)
  list_notes -> no finding      (identity constraint in the query)

4.2 authors the sink facts the go/no-go measured as its largest miss class (11
of 23): Django ORM raw SQL, and the four families that previously had no fact
routing to them by CWE at all -- path, output_encoding, untrusted_destination,
prototype. Each entry is a documented dangerous API of the named library with
its provenance recorded inline, and rule_ids left empty because a sink fact is
not a detection rule. Flagged for maintainer review as data, given the standing
"no LLM-authored patterns" constraint. The exact-set assertion written in task
1.1 to hold this gap open is updated rather than deleted, so it still fails if a
family ever loses its seed.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-08 14:45:12 +02:00
Marius CiepluchandClaude Opus 5 b8f8f727c6 feat(model-grounded-detection): group 3, the evidence ladder and the judge
3.1 adds StaticFinding.rung beside evidence_level rather than renaming it. The
existing evidence_level carries `static_corroboration`, emitted by the flat IR
overlay -- a path Req 4.4 demotes to the suspicion band. Restating that as
model_corroborated would claim a CPG arbitrated something it never saw, and
rewriting every legacy finding to suspicion would be a product-visible
regression nobody asked for. So `rung` defaults to suspicion and is raised only
by ladder.at_rung(finding, verdict), which is the structural form of Req 5.4:
nothing rises above suspicion without a Verdict behind it. The witness travels
with the rung, because a rung without its evidence is just a louder assertion.
It reaches markdown, JSON and SARIF.

3.2 is the judge, and it is defined as much by what it lacks. Three exhaustive
outcomes: the model entails (report it, never call the model), the model
contradicts (drop the claim, record why), the model cannot decide (report
suspicion). The LLM gets one bounded typed question with tools=[] so it cannot
search for the site, asked only about the residual the graph cannot settle --
whether a sanitizer on a REAL flow suffices. Its answer can only confirm a flow
the CPG already found; it can never conjure one.

Req 8.5 is asserted structurally: a test parses judge.py and fails on any AST
name like k_runs/majority/vote/average/acceptance/floor/budget, any for/while
loop, or an import from the deleted round machinery. That test first matched
the word "votes" in the module's own docstring, which is why it now inspects
code rather than text.

Verified live against a real CPG, not only scripted rows:
  vuln   rung=model_entailed   request.args["name"] -> db.execute(...)
  fixed  rung=suspicion        no source reaches this sink
  model calls made: 0

Both sides arbitrated by the graph with the LLM never consulted -- the thing
the prior architecture could not do at any price.

678 passing, mypy/ruff clean, gates byte-identical, zero orphaned modules.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-08 13:49:55 +02:00
Marius CiepluchandClaude Opus 5 2b973dc0db feat(model-grounded-detection): tasks 2.1-2.2, the Joern seam and the taint verdict
The whole engine integration is one subprocess boundary: joern-parse builds a
cpg.bin, joern --script runs a shipped CPGQL query that prints its JSON between
fence markers, because Joern's stdout carries a banner and a REPL prompt around
whatever a script emits. Nothing is imported in-process, so the core install
keeps dependencies = [] -- a test walks the seam's AST to assert it imports
only the standard library and names no JVM binding.

Fail closed everywhere. A build or query that errors, times out, or prints
something unparseable yields no verdict and the caller reports suspicion. The
taint verdict distinguishes this from absence deliberately: a query returning
None means "the engine could not decide", which is not "there is no flow", and
conflating them is how a missing engine silently becomes a clean bill of health.

The verdict is where the ladder earns its keep. An unsanitized source->sink
path is model_entailed -- the graph establishes it and the LLM's claim is no
longer load-bearing. A path a sanitizer may break is model_corroborated: the
flow is real, but whether the sanitizer suffices is the semantic residual the
LLM answers, checked against this verdict rather than averaged over runs. The
chosen flow is picked by a total order (shortest, then lexicographic), so two
runs over one CPG cannot disagree -- Req 6.4 asserted directly.

The query itself is the part our flat IR could not do: reachableByFlows walks
the PDG, so `q = "..." + request.args["x"]; execute(q)` is found, which is
exactly the one-hop limit that held measured entailment at 2.2%.

Capability detection reuses semantic/engines.joern_available rather than
growing a second notion of "installed". The audit manifest is regenerated; the
new modules are named by Req 4/5/6 rather than counted as orphans.

Task 2.3, the go/no-go measurement, needs Joern installed and has not run.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-08 12:23:40 +02:00
Marius CiepluchandClaude Opus 5 9ed0e45c5f feat(model-grounded-detection): group 1, subtract the noise architecture
99 source modules -> 81. 832 tests -> 646. The whole learning/ package (16
modules, ~4,100 lines) and six semantic/ modules removed, with the three gates
byte-identical to 2026-09-06-gate-baseline.txt at every step.

The sequence is what made it safe: vocabularies ported first (1.1), importers
detached second (1.2-1.3), deletion third (1.4). Every import break during the
deletion was therefore a detachment miss in the importer and was fixed there --
no module was restored to satisfy one. Both misses were the same shape and were
fixed as a class: operations.py and shapes.py each imported trailing_name from
the deleted variants.py, so it moved to semantic/ir.py, its natural home, and
both importers changed in one edit.

Ported before deleting: the closed guard vocabulary (verbatim, nothing else
holds it) into model/specs.py, which derives TaintSpec and DominanceSpec from
the retained ruleset facts rather than copying them. Re-homed: families ->
model/taxonomy, candidates -> model/candidates, endpoint -> model/endpoint,
plus Region, labeled_family and labeled_spans. labeled_family no longer falls
back to the LLM classifier -- an unlabeled pair is honestly unknown.

Four deviations, each recorded in the spec notes with its reason. improve/
evolve.py and validator.py were stripped, not deleted: each mixes the mechanism
lever (gone) with the deterministic rule-status loop `ousast improve` still
runs, which has no LLM in it; a test now asserts the lever's absence by symbol
so it cannot creep back. The learning CLI group became `model candidates`,
because deleting it outright would have orphaned the retained enumerator by
removing its only entry point. thinking moved from [learning] to [models].

A gap named rather than papered over: no retained sink fact routes by CWE to
path, output_encoding, untrusted_destination or prototype -- the same hole the
entailment ceiling diagnosed. The test asserts the seeded set and the gap set
exactly, so task 4.2 must update it when it authors those sinks.

The audit found exactly one genuine orphan: vectorstore.py, a bakeoff harness
with no production caller and no CLI, alive only through its own test. The five
named subsystems each carry an explicit decision. Manifest committed, with a
test asserting the tree still matches it.

Group 2 (the Joern go/no-go) has not started.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-08 12:15:54 +02:00