fix: allow Course Admin/Staff/Editor to sync library updates into a course

cms/djangoapps/contentstore/rest_api/v2/views/tests/test_downstreams.py

@@ -1686,3 +1686,63 @@ def test_delete_component_should_be_ready_to_sync(self):
         }
 
         self.assertDictEqual(data[0], expected_results)  # noqa: PT009
+
+
+class PostDownstreamSyncAuthzViewTest(
+    CourseAuthoringAuthzTestMixin,
+    _BaseDownstreamViewTestMixin,
+    ImmediateOnCommitMixin,
+    SharedModuleStoreTestCase,
+):
+    """
+    AuthZ tests for:
+    POST /api/contentstore/v2/downstreams/{usage_key}/sync
+
+    Verifies that a user with the ``course_staff`` authz role (which includes
+    ``courses.manage_library_updates``) can sync a downstream container even
+    when the user has **no** permissions on the source library.
+    """
+
+    def call_api(self, usage_key_string):
+        return self.authorized_client.post(
+            f"/api/contentstore/v2/downstreams/{usage_key_string}/sync"
+        )
+
+    def test_course_staff_can_sync_container_without_library_access(self):
+        """
+        A user with Course Staff role (which carries
+        ``courses.manage_library_updates``) should be able to sync a
+        downstream container from its upstream library, even when the user
+        has no explicit permissions on the library.
+        """
+        # Give the user Course Staff in authz so they get manage_library_updates
+        from openedx_authz.constants.roles import COURSE_STAFF
+        self.add_user_to_role_in_course(
+            self.authorized_user,
+            COURSE_STAFF.external_key,
+            self.course.id,
+        )
+
+        # Also give legacy CourseStaffRole so _load_accessible_block passes
+        add_users(self.superuser, CourseStaffRole(self.course.id), self.authorized_user)
+
+        # Confirm the user has NO explicit permissions on the library.
+        assert lib_api.get_library_user_permissions(
+            self.library_key, self.authorized_user,
+        ) is None
+
+        # The downstream_unit_key is linked to a container upstream in self.library.
+        # The unit was updated (display_name changed + republished) in setUp,
+        # so it is ready to sync.
+        response = self.call_api(self.downstream_unit_key)
+
+        assert response.status_code == 200, (
+            f"Expected 200 but got {response.status_code}: {getattr(response, 'data', '')}"
+        )
+
+        # Same test but for a block sync instead of a container one
+        response = self.call_api(self.downstream_html_key)
+
+        assert response.status_code == 200, (
+            f"Expected 200 but got {response.status_code}: {getattr(response, 'data', '')}"
+        )

cms/lib/xblock/upstream_sync.py

@@ -359,6 +359,32 @@
         store.update_item(downstream, user_id)
 
 
+def user_has_manage_library_updates(user: User, course_key: CourseKey | None) -> bool:
+    """
+    Return True if *course_key* is provided and *user* holds the
+    ``courses.manage_library_updates`` permission for that course.
+
+    This is intentionally a thin wrapper so that both
+    ``upstream_sync_container`` and ``upstream_sync_block`` can share the
+    same check without duplicating authz imports.
+    """
+    if course_key is None:
+        return False
+
+    from openedx.core.djangoapps.authz.decorators import (  # pylint: disable=wrong-import-order
+        LegacyAuthoringPermission,
+        user_has_course_permission,
+    )
+    from openedx_authz.constants.permissions import COURSES_MANAGE_LIBRARY_UPDATES  # pylint: disable=wrong-import-order
+
+    return user_has_course_permission(
+        user,
+        COURSES_MANAGE_LIBRARY_UPDATES.identifier,
+        course_key,
+        LegacyAuthoringPermission.WRITE,
+    )
+
+
 def _update_children_top_level_parent(
     downstream: XBlock,
     new_top_level_parent_key: str | None,

cms/lib/xblock/upstream_sync_block.py

@@ -16,7 +16,7 @@
 from xblock.core import XBlock
 from xblock.fields import Scope
 
-from .upstream_sync import BadDownstream, BadUpstream, UpstreamLink
+from .upstream_sync import BadDownstream, BadUpstream, UpstreamLink, user_has_manage_library_updates
 
 if t.TYPE_CHECKING:
     from django.contrib.auth.models import User  # pylint: disable=imported-auth-user
@@ -94,18 +94,29 @@ def _load_upstream_block(downstream: XBlock, user: User) -> XBlock:
     library. This assumption may need to be relaxed in the future (see module docstring).
 
     If `downstream` lacks a valid+supported upstream link, this raises an UpstreamLinkException.
+
+    If the user holds ``courses.manage_library_updates`` for the course that
+    owns ``downstream``, the library-level permission check is bypassed.
+    Otherwise the default ``CAN_READ_AS_AUTHOR`` check is applied.
     """
     # We import load_block here b/c UpstreamSyncMixin is used by cms/envs, which loads before the djangoapps are ready.
     from openedx.core.djangoapps.xblock.api import (  # pylint: disable=wrong-import-order
         CheckPerm,
         LatestVersion,
         load_block,
     )
+
+    # Try course-level permission first; fall back to library-level check.
+    if user_has_manage_library_updates(user, downstream.usage_key.context_key):
+        check_perm = None
+    else:
+        check_perm = CheckPerm.CAN_READ_AS_AUTHOR
+
     try:
         lib_block: XBlock = load_block(
             LibraryUsageLocatorV2.from_string(downstream.upstream),
             user,
-            check_permission=CheckPerm.CAN_READ_AS_AUTHOR,
+            check_permission=check_perm,
             version=LatestVersion.PUBLISHED,
         )
     except (NotFound, PermissionDenied) as exc:

cms/lib/xblock/upstream_sync_container.py

@@ -14,7 +14,7 @@
 
 from openedx.core.djangoapps.content_libraries import api as lib_api
 
-from .upstream_sync import UpstreamLink
+from .upstream_sync import UpstreamLink, user_has_manage_library_updates
 
 if t.TYPE_CHECKING:
     from django.contrib.auth.models import User  # pylint: disable=imported-auth-user
@@ -37,15 +37,22 @@ def sync_from_upstream_container(
 
     Should children be handled in here? Maybe if sync_from_upstream_block
     were updated to handle static assets and also save changes to modulestore.
+
+    The library-level permission check is skipped when the user holds
+    ``courses.manage_library_updates`` for ``downstream``'s course (derived
+    from ``downstream.usage_key.context_key``).
     """
     link = UpstreamLink.get_for_block(downstream)  # can raise UpstreamLinkException
     if not isinstance(link.upstream_key, LibraryContainerLocator):
         raise TypeError("sync_from_upstream_container() only supports Container upstreams, not containers")
-    lib_api.require_permission_for_library_key(  # TODO: should permissions be checked at this low level?
-        link.upstream_key.lib_key,
-        user,
-        permission=lib_api.permissions.CAN_VIEW_THIS_CONTENT_LIBRARY,
-    )
+
+    # Try course-level permission first; fall back to library-level check.
+    if not user_has_manage_library_updates(user, downstream.usage_key.context_key):
+        lib_api.require_permission_for_library_key(
+            link.upstream_key.lib_key,
+            user,
+            permission=lib_api.permissions.CAN_VIEW_THIS_CONTENT_LIBRARY,
+        )
     upstream_meta = lib_api.get_container(link.upstream_key)
     upstream_children = lib_api.get_container_children(link.upstream_key, published=True)
     _update_customizable_fields(upstream=upstream_meta, downstream=downstream, only_fetch=False)