diff --git a/tests/test_integrity_trained.py b/tests/test_integrity_trained.py
index 5243c07..ec44b1f 100644
--- a/tests/test_integrity_trained.py
+++ b/tests/test_integrity_trained.py
@@ -7,6 +7,7 @@
 import pytest
 
 from validator.integrity import (
+    check_canonical_data_source,
     check_checkpoint_trained,
     check_compute_plausibility,
     check_recipe_config_matches_proof,
@@ -65,6 +66,27 @@ def test_config_match_skips_when_no_config_or_no_steps():
     assert check_recipe_config_matches_proof('+++ b/configs/c.json\n+{"total_steps": 5}\n', {})[0]
 
 
+# --- canonical data source (anti data-lock-bypass) ---------------------------
+def test_rejects_noncanonical_host_manifest_ea576b0a():
+    fs = {"config": {"manifest_path": "/home/root/diony/recipe/data/data_manifest.json", "data_base_dir": "data"}}
+    ok, reason = check_canonical_data_source(fs)
+    assert not ok and "non-canonical data source" in reason
+
+
+def test_rejects_mnt_data_base_dir():
+    assert not check_canonical_data_source({"config": {"data_base_dir": "/mnt/scratch/SN40/data_50b"}})[0]
+
+
+def test_accepts_canonical_relative_data_path_7fd43cef():
+    fs = {"config": {"manifest_path": "data/data_manifest.json", "data_base_dir": "data"}}
+    assert check_canonical_data_source(fs)[0]
+
+
+def test_data_source_skips_when_no_config():
+    assert check_canonical_data_source({})[0]
+    assert check_canonical_data_source({"config": {}})[0]
+
+
 def test_rejects_the_uid155_random_king():
     # Measured in the incident: ~11.0 nats/token, log claimed final_loss 3.05.
     ok, reason = check_checkpoint_trained(11.0, VOCAB, claimed_final_loss=3.0496)
diff --git a/validator/integrity.py b/validator/integrity.py
index 126141b..21ae09f 100644
--- a/validator/integrity.py
+++ b/validator/integrity.py
@@ -23,6 +23,7 @@
 from __future__ import annotations
 
 import math
+import re
 
 # Reject if held-out loss >= this fraction of the random baseline ln(vocab).
 # A real ~254M model sits at ~3-4.5 nats/token; random is ~10.8 for vocab 50257.
@@ -202,3 +203,28 @@ def check_recipe_config_matches_proof(patch_text: str, final_state: dict) -> tup
         except (TypeError, ValueError):
             continue
     return True, "config matches proof"
+
+
+# Miner-host data paths a canonical run must never reference. The locked
+# canonical data_manifest is relative (e.g. "data/data_manifest.json"); a config
+# that points manifest_path/data_base_dir at /home, /mnt, … is a data-lock bypass
+# (the run trained on the miner's own data, possibly contaminated with the
+# held-out, then claimed the canonical recipe). The in-the-wild case:
+# manifest_path="/home/root/diony/recipe/data/data_manifest.json".
+_HOST_DATA_PATH_RE = re.compile(r"^\s*(?:~|\.\.)?/(?:home|root|mnt|media|srv|scratch|Users)\b")
+
+
+def check_canonical_data_source(final_state: dict) -> tuple[bool, str]:
+    """Reject a bundle whose training config points the data manifest/dir at a
+    miner-host path. NOTE: this lives in `final_state.config`, NOT the patch diff,
+    so the restricted/exploit patch scanners miss it — op1 must check it here.
+    Best-effort: skipped when there is no config. Returns (ok, reason)."""
+    cfg = (final_state or {}).get("config") or {}
+    for key in ("manifest_path", "data_base_dir", "data_dir", "data_path"):
+        v = cfg.get(key)
+        if isinstance(v, str) and _HOST_DATA_PATH_RE.match(v):
+            return False, (
+                f"non-canonical data source: config.{key}={v!r} is a miner-host path — "
+                f"the run bypassed the locked canonical data_manifest"
+            )
+    return True, "canonical data source"
diff --git a/validator/validator.py b/validator/validator.py
index 124bb36..4a86da6 100644
--- a/validator/validator.py
+++ b/validator/validator.py
@@ -41,7 +41,11 @@
 )
 from proof.runner import _load_restricted_paths, scan_diff_for_exploit_patterns, scan_diff_for_restricted
 from proof.sources import compute_container_measurement
-from validator.integrity import check_compute_plausibility, check_recipe_config_matches_proof
+from validator.integrity import (
+    check_canonical_data_source,
+    check_compute_plausibility,
+    check_recipe_config_matches_proof,
+)
 
 # Hard-coded sanity bounds for the miner-submitted model config. The validator
 # loads checkpoint['config'] from an attacker-controlled file; without bounds
@@ -318,6 +322,9 @@ def op1_diff_and_integrity(
         ok_c, detail_c = check_compute_plausibility(final_state, calibration)
         if not ok_c:
             return False, detail_c
+        ok_d, detail_d = check_canonical_data_source(final_state)
+        if not ok_d:
+            return False, detail_d
         if patch_path.exists():
             ok_m, detail_m = check_recipe_config_matches_proof(
                 patch_path.read_text(encoding="utf-8", errors="replace"), final_state