fix: enforce feature permissions on the legacy chat-features block (image_generation, web_search) (#26703)

The legacy features block in process_chat_payload honoured client-supplied features.image_generation and features.web_search flags and dispatched to the image generation/edit provider and the web-search provider without re-checking the per-user permission that the direct /images routes and the native function-calling path enforce. A user denied features.image_generation or features.web_search could still trigger billable server-side image generation or web search via POST /api/chat/completions with params.function_calling set to legacy. Gate both branches on admin-or-has_permission before invoking chat_image_generation_handler / chat_web_search_handler, matching the existing code_interpreter gate, so a forged flag from an unpermitted user is ignored. Normal completions and permitted users are unaffected.

backend/open_webui/utils/middleware.py

@@ -2523,14 +2523,26 @@ async def process_chat_payload(request, form_data, user, metadata, model):
             form_data = await add_memory_context(request, form_data, user, model)
 
         if 'web_search' in features and features['web_search']:
-            # Skip forced RAG web search when native FC is enabled - model can use web_search tool
+            # features is client-supplied; re-check the permission the native FC path enforces.
-            if metadata.get('params', {}).get('function_calling') == 'legacy':
+            if getattr(user, 'role', None) == 'admin' or await has_permission(
-                form_data = await chat_web_search_handler(request, form_data, extra_params, user)
+                getattr(user, 'id', ''),
+                'features.web_search',
+                await Config.get('user.permissions'),
+            ):
+                # Skip forced RAG web search when native FC is enabled - model can use web_search tool
+                if metadata.get('params', {}).get('function_calling') == 'legacy':
+                    form_data = await chat_web_search_handler(request, form_data, extra_params, user)
 
         if 'image_generation' in features and features['image_generation']:
-            # Skip forced image generation when native FC is enabled - model can use generate_image tool
+            # features is client-supplied; re-check the permission the direct /images routes enforce.
-            if metadata.get('params', {}).get('function_calling') == 'legacy':
+            if getattr(user, 'role', None) == 'admin' or await has_permission(
-                form_data = await chat_image_generation_handler(request, form_data, extra_params, user)
+                getattr(user, 'id', ''),
+                'features.image_generation',
+                await Config.get('user.permissions'),
+            ):
+                # Skip forced image generation when native FC is enabled - model can use generate_image tool
+                if metadata.get('params', {}).get('function_calling') == 'legacy':
+                    form_data = await chat_image_generation_handler(request, form_data, extra_params, user)
 
         if 'code_interpreter' in features and features['code_interpreter']:
             engine = await Config.get('code_interpreter.engine', 'pyodide')