Merge pull request from GHSA-mp9m-g7qj-6vqr

* Query members for unchunked guilds in massban

* that thing that is a thing ;)

redbot/cogs/mod/kickban.py

@@ -2,7 +2,7 @@ import asyncio
 import contextlib
 import logging
 from datetime import datetime, timedelta, timezone
-from typing import Optional, Tuple, Union
+from typing import Dict, List, Optional, Tuple, Union
 
 import discord
 from redbot.core import commands, i18n, checks, modlog
@@ -440,28 +440,41 @@ class KickBanMixin(MixinMeta):
             await show_results()
             return
 
+        # We need to check here, if any of the users isn't a member and if they are,
+        # we need to use our `ban_user()` method to do hierarchy checks.
+        members: Dict[int, discord.Member] = {}
+        to_query: List[int] = []
+
         for user_id in user_ids:
-            user = guild.get_member(user_id)
-            if user is not None:
-                if user_id in tempbans:
-                    # We need to check if a user is tempbanned here because otherwise they won't be processed later on.
-                    continue
+            member = guild.get_member(user_id)
+            if member is not None:
+                members[user_id] = member
+            elif not guild.chunked:
+                to_query.append(user_id)
+
+        # If guild isn't chunked, we might possibly be missing the member from cache,
+        # so we need to make sure that isn't the case by querying the user IDs for such guilds.
+        while to_query:
+            queried_members = await guild.query_members(user_ids=to_query[:100], limit=100)
+            members.update((member.id, member) for member in queried_members)
+            to_query = to_query[100:]
+
+        # Call `ban_user()` method for all users that turned out to be guild members.
+        for member in members:
+            try:
+                success, reason = await self.ban_user(
+                    user=member, ctx=ctx, days=days, reason=reason, create_modlog_case=True
+                )
+                if success:
+                    banned.append(user_id)
                 else:
-                    # Instead of replicating all that handling... gets attr from decorator
-                    try:
-                        success, reason = await self.ban_user(
-                            user=user, ctx=ctx, days=days, reason=reason, create_modlog_case=True
-                        )
-                        if success:
-                            banned.append(user_id)
-                        else:
-                            errors[user_id] = _("Failed to ban user {user_id}: {reason}").format(
-                                user_id=user_id, reason=reason
-                            )
-                    except Exception as e:
-                        errors[user_id] = _("Failed to ban user {user_id}: {reason}").format(
-                            user_id=user_id, reason=e
-                        )
+                    errors[user_id] = _("Failed to ban user {user_id}: {reason}").format(
+                        user_id=user_id, reason=reason
+                    )
+            except Exception as e:
+                errors[user_id] = _("Failed to ban user {user_id}: {reason}").format(
+                    user_id=user_id, reason=e
+                )
 
         user_ids = remove_processed(user_ids)