Fix dungeon reset exploit when switching leader.

1. A enters dungeon.

2. B enters dungeon.

3. A invites B to group.

4. A promotes B to leader.

5. A relogs.

6. A finds himself in B's instance but at his old position on the map.

sql/migrations/20241002031703_characters.sql

@@ -0,0 +1,22 @@
+DROP PROCEDURE IF EXISTS add_migration;
+DELIMITER ??
+CREATE PROCEDURE `add_migration`()
+BEGIN
+DECLARE v INT DEFAULT 1;
+SET v = (SELECT COUNT(*) FROM `migrations` WHERE `id`='20241002031703');
+IF v = 0 THEN
+INSERT INTO `migrations` VALUES ('20241002031703');
+-- Add your query below.
+
+
+-- Add instance id player logged out inside of to characters table to prevent exploits.
+ALTER TABLE `characters`
+	ADD COLUMN `instance_id` INT(11) UNSIGNED NOT NULL DEFAULT '0' AFTER `map`;
+
+
+-- End of migration.
+END IF;
+END??
+DELIMITER ;
+CALL add_migration();
+DROP PROCEDURE IF EXISTS add_migration;

src/game/Group/Group.cpp

@@ -1688,11 +1688,12 @@ void Group::_setLeader(ObjectGuid guid)
     if (slot == m_memberSlots.end())
         return;
 
+    MANGOS_ASSERT(guid != m_leaderGuid);
+
     if (!isBGGroup())
     {
-        uint32 slot_lowguid = slot->guid.GetCounter();
-
-        uint32 leader_lowguid = m_leaderGuid.GetCounter();
+        uint32 newLeaderLowGuid = slot->guid.GetCounter();
+        uint32 oldLeaderLowGuid = m_leaderGuid.GetCounter();
 
         // TODO: set a time limit to have this function run rarely cause it can be slow
         CharacterDatabase.BeginTransaction(m_Id);
@@ -1705,7 +1706,7 @@ void Group::_setLeader(ObjectGuid guid)
         CharacterDatabase.PExecute(
             "DELETE FROM `group_instance` WHERE `leader_guid`='%u' AND (`permanent` = 1 OR "
             "`instance` IN (SELECT `instance` FROM `character_instance` WHERE `guid` = '%u')"
-            ")", leader_lowguid, slot_lowguid);
+            ")", oldLeaderLowGuid, newLeaderLowGuid);
 
         Player* player = sObjectMgr.GetPlayer(slot->guid);
 
@@ -1718,22 +1719,34 @@ void Group::_setLeader(ObjectGuid guid)
                     itr->second.state->RemoveGroup(this);
                     m_boundInstances.erase(itr++);
                 }
+                else if (InstancePlayerBind* pPersonalBind = player->GetBoundInstance(itr->first))
+                {
+                    // if the new leader already has a personal save for this instance, then remove the current group save
+                    if (Player* pOldLeader = sObjectMgr.GetPlayer(m_leaderGuid))
+                        if (!pOldLeader->GetBoundInstance(itr->first))
+                            pOldLeader->BindToInstance(itr->second.state, itr->second.perm, false);
+
+                    CharacterDatabase.PExecute("DELETE FROM `group_instance` WHERE `leader_guid` = '%u' AND `instance` = '%u'",
+                        oldLeaderLowGuid, itr->second.state->GetInstanceId());
+                    itr->second.state->RemoveGroup(this);
+                    m_boundInstances.erase(itr++);
+                }
                 else
                     ++itr;
             }
         }
 
         // update the group's solo binds to the new leader
         CharacterDatabase.PExecute("UPDATE `group_instance` SET `leader_guid`='%u' WHERE `leader_guid` = '%u'",
-                                   slot_lowguid, leader_lowguid);
+                                   newLeaderLowGuid, oldLeaderLowGuid);
 
         // copy the permanent binds from the new leader to the group
         // overwriting the solo binds with permanent ones if necessary
         // in the DB those have been deleted already
         Player::ConvertInstancesToGroup(player, this, slot->guid);
 
         // update the group leader
-        CharacterDatabase.PExecute("UPDATE `groups` SET `leader_guid`='%u' WHERE `group_id`='%u'", slot_lowguid, m_Id);
+        CharacterDatabase.PExecute("UPDATE `groups` SET `leader_guid`='%u' WHERE `group_id`='%u'", newLeaderLowGuid, m_Id);
         CharacterDatabase.CommitTransaction();
     }
 

src/game/Handlers/CharacterHandler.cpp

@@ -83,7 +83,7 @@ bool LoginQueryHolder::Initialize()
                      "`reset_talents_time`, `transport_guid`, `transport_x`, `transport_y`, `transport_z`, `transport_o`, `extra_flags`, `stable_slots`, `at_login_flags`, `zone`, `online`, `death_expire_time`, `current_taxi_path`, "
                      "`honor_rank_points`, `honor_highest_rank`, `honor_standing`, `honor_last_week_hk`, `honor_last_week_cp`, `honor_stored_hk`, `honor_stored_dk`, "
                      "`watched_faction`, `drunk`, `health`, `power1`, `power2`, `power3`, `power4`, `power5`, `explored_zones`, `equipment_cache`, `ammo_id`, `action_bars`, "
-                     "`world_phase_mask`, `create_time` FROM `characters` WHERE `guid` = '%u'", m_guid.GetCounter());
+                     "`world_phase_mask`, `create_time`, `instance_id` FROM `characters` WHERE `guid` = '%u'", m_guid.GetCounter());
     res &= SetPQuery(PLAYER_LOGIN_QUERY_LOADGROUP,           "SELECT `group_id` FROM `group_member` WHERE `member_guid` ='%u'", m_guid.GetCounter());
     res &= SetPQuery(PLAYER_LOGIN_QUERY_LOADBOUNDINSTANCES,  "SELECT `id`, `permanent`, `map`, `reset_time` FROM `character_instance` LEFT JOIN `instance` ON `instance` = `id` WHERE `guid` = '%u'", m_guid.GetCounter());
     res &= SetPQuery(PLAYER_LOGIN_QUERY_LOADAURAS,           "SELECT `caster_guid`, `item_guid`, `spell`, `stacks`, `charges`, `base_points0`, `base_points1`, `base_points2`, `periodic_time0`, `periodic_time1`, `periodic_time2`, `max_duration`, `duration`, `effect_index_mask` FROM `character_aura` WHERE `guid` = '%u'", m_guid.GetCounter());

src/game/Objects/Player.cpp

@@ -15083,8 +15083,8 @@ bool Player::LoadFromDB(ObjectGuid guid, SqlQueryHolder* holder)
     //"honor_rank_points, honor_highest_rank, honor_standing, honor_last_week_hk, honor_last_week_cp, honor_stored_hk, honor_stored_dk,"
     // 48                49     50      51      52      53      54      55      56              57               58       59
     //"watched_faction,  drunk, health, power1, power2, power3, power4, power5, explored_zones, equipment_cache, ammo_id, action_bars,"
-    // 60                61
-    //"world_phase_mask, create_time FROM characters WHERE guid = '%u'", GUID_LOPART(m_guid));
+    // 60                61           62
+    //"world_phase_mask, create_time, instance_id FROM characters WHERE guid = '%u'", GUID_LOPART(m_guid));
 
     std::unique_ptr<QueryResult> result = holder->TakeResult(PLAYER_LOGIN_QUERY_LOADFROM);
 
@@ -15341,7 +15341,8 @@ bool Player::LoadFromDB(ObjectGuid guid, SqlQueryHolder* holder)
     if (mapEntry && mapEntry->IsDungeon())
     {
         // if the player is in an instance and it has been reset in the meantime teleport him to the entrance
-        if (!state)
+        uint32 instanceId = fields[62].GetUInt32();
+        if (!state || state->GetInstanceId() != instanceId)
         {
             AreaTriggerTeleport const* at = sObjectMgr.GetGoBackTrigger(GetMapId());
             if (at)
@@ -16848,7 +16849,7 @@ void Player::SaveToDB(bool online, bool force)
     static SqlStatementID insChar;
 
     SqlStatement uberInsert = CharacterDatabase.CreateStatement(insChar, "REPLACE INTO `characters` (`guid`, `account`, `name`, `race`, `class`, `gender`, `level`, `xp`, `money`, `skin`, `face`, `hair_style`, `hair_color`, `facial_hair`, `bank_bag_slots`, `player_flags`,"
-                              "`map`, `position_x`, `position_y`, `position_z`, `orientation`, "
+                              "`map`, `instance_id`, `position_x`, `position_y`, `position_z`, `orientation`, "
                               "`transport_guid`, `transport_x`, `transport_y`, `transport_z`, `transport_o`, "
                               "`known_taxi_mask`, `current_taxi_path`, `online`, `played_time_total`, `played_time_level`, "
                               "`rest_bonus`, `logout_time`, `is_logout_resting`, `reset_talents_multiplier`, `reset_talents_time`, "
@@ -16857,7 +16858,7 @@ void Player::SaveToDB(bool online, bool force)
                               "`watched_faction`, `drunk`, `health`, `power1`, `power2`, `power3`, `power4`, `power5`, "
                               "`explored_zones`, `equipment_cache`, `ammo_id`, `action_bars`, `world_phase_mask`, `create_time`) "
                               "VALUES ( ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, "
-                              "?, ?, ?, ?, ?, "
+                              "?, ?, ?, ?, ?, ?, "
                                "?, ?, ?, ?, ?, "
                               "?, ?, ?, ?, ?, "
                               "?, ?, ?, ?, ?, "
@@ -16891,6 +16892,7 @@ void Player::SaveToDB(bool online, bool force)
     if (!IsBeingTeleported())
     {
         uberInsert.addUInt32(GetMapId());
+        uberInsert.addUInt32(GetInstanceId());
         uberInsert.addFloat(finiteAlways(GetPositionX()));
         uberInsert.addFloat(finiteAlways(GetPositionY()));
         uberInsert.addFloat(finiteAlways(GetPositionZ()));
@@ -16899,6 +16901,7 @@ void Player::SaveToDB(bool online, bool force)
     else
     {
         uberInsert.addUInt32(GetTeleportDest().mapId);
+        uberInsert.addUInt32(0);
         uberInsert.addFloat(finiteAlways(GetTeleportDest().x));
         uberInsert.addFloat(finiteAlways(GetTeleportDest().y));
         uberInsert.addFloat(finiteAlways(GetTeleportDest().z));