Fix DAG named "DAGs" colliding with the global DAGs permission resource

airflow-core/src/airflow/security/permissions.py

@@ -106,8 +106,10 @@ class ResourceDetails(TypedDict):
 
 def resource_name(dag_id: str, resource: str) -> str:
     """Return the resource name for a DAG id."""
-    if dag_id in RESOURCE_DETAILS_MAP.keys():
-        return dag_id
+    # NB: do not short-circuit when ``dag_id`` equals a reserved resource name
+    # (e.g. "DAGs"). A real ``dag_id`` can collide with one, and returning it
+    # unchanged would map the per-DAG resource onto the global resource. Only an
+    # already-prefixed value (e.g. "DAG:foo") is returned as-is.
     if dag_id.startswith(tuple(PREFIX_RESOURCES_MAP.keys())):
         return dag_id
     return f"{RESOURCE_DETAILS_MAP[resource]['prefix']}{dag_id}"

airflow-core/tests/unit/security/test_permissions.py

@@ -0,0 +1,35 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from __future__ import annotations
+
+from airflow.security import permissions
+
+
+def test_resource_name_does_not_collide_with_reserved_resource_names():
+    """A dag_id equal to a reserved resource name must be prefixed, not returned as-is.
+
+    Regression for the case where a DAG literally named ``DAGs`` resolved to the
+    global all-DAGs resource instead of its own ``DAG:DAGs`` resource.
+    """
+    # "DAGs" is the global resource name *and* a valid dag_id — it must resolve to
+    # the per-DAG resource, never be returned unchanged.
+    assert permissions.resource_name(permissions.RESOURCE_DAG, permissions.RESOURCE_DAG) == "DAG:DAGs"
+    # Ordinary dag_ids are prefixed as before.
+    assert permissions.resource_name("my_dag", permissions.RESOURCE_DAG) == "DAG:my_dag"
+    # Already-prefixed names stay idempotent (the surviving short-circuit branch).
+    assert permissions.resource_name("DAG:my_dag", permissions.RESOURCE_DAG) == "DAG:my_dag"

providers/fab/src/airflow/providers/fab/www/security/permissions.py

@@ -96,8 +96,10 @@ class ResourceDetails(TypedDict):
 
 def resource_name(dag_id: str, resource: str) -> str:
     """Return the resource name for a DAG id."""
-    if dag_id in RESOURCE_DETAILS_MAP.keys():
-        return dag_id
+    # NB: do not short-circuit when ``dag_id`` equals a reserved resource name
+    # (e.g. "DAGs"). A real ``dag_id`` can collide with one, and returning it
+    # unchanged would map the per-DAG resource onto the global resource. Only an
+    # already-prefixed value (e.g. "DAG:foo") is returned as-is.
     if dag_id.startswith(tuple(PREFIX_RESOURCES_MAP.keys())):
         return dag_id
     return f"{RESOURCE_DETAILS_MAP[resource]['prefix']}{dag_id}"

providers/fab/tests/unit/fab/auth_manager/test_security.py

@@ -1273,3 +1273,22 @@ def test_add_user_uses_configured_hash_method(mock_hash, app, security_manager):
                 mock_hash.assert_called_with("plaintext", method="pbkdf2:sha256")
             finally:
                 delete_user(app, "hash_method_add_test")
+
+
+def test_resource_name_does_not_collide_with_reserved_resource_names():
+    """A dag_id equal to a reserved resource name must be prefixed, not returned as-is.
+
+    Regression for the case where a DAG literally named ``DAGs`` resolved to the
+    global all-DAGs resource instead of its own ``DAG:DAGs`` resource.
+    """
+    # "DAGs" is the global resource name *and* a valid dag_id — it must resolve to
+    # the per-DAG resource, never be returned unchanged.
+    assert permissions.resource_name(permissions.RESOURCE_DAG, permissions.RESOURCE_DAG) == "DAG:DAGs"
+    # Ordinary dag_ids are prefixed as before.
+    assert permissions.resource_name("my_dag", permissions.RESOURCE_DAG) == "DAG:my_dag"
+    # Already-prefixed names stay idempotent (the surviving short-circuit branch).
+    assert permissions.resource_name("DAG:my_dag", permissions.RESOURCE_DAG) == "DAG:my_dag"
+    # Sanity: an access_control sync resolves a DAG named "DAGs" to its per-DAG
+    # resource, so the permission is granted on "DAG:DAGs", never the global "DAGs".
+    # The grant in _sync_dag_view_permissions goes to exactly resource_name(dag_id, ...),
+    # so the assertion above is what guards the privilege-escalation regression.