From edcf740d8e3d2b296015f13626dabff83cde74f0 Mon Sep 17 00:00:00 2001
From: Zach Brown <zach@zachbr.io>
Date: Thu, 16 Apr 2020 20:07:29 -0500
Subject: [PATCH] Restrict vanilla teleport command to valid locations

Fixes GH-3165

diff --git a/src/main/java/net/minecraft/server/CommandTeleport.java b/src/main/java/net/minecraft/server/CommandTeleport.java
index 3060b4f68..79016b587 100644
--- a/src/main/java/net/minecraft/server/CommandTeleport.java
+++ b/src/main/java/net/minecraft/server/CommandTeleport.java
@@ -116,6 +116,12 @@ public class CommandTeleport {
     }
 
     private static void a(CommandListenerWrapper commandlistenerwrapper, Entity entity, WorldServer worldserver, double d0, double d1, double d2, Set<PacketPlayOutPosition.EnumPlayerTeleportFlags> set, float f, float f1, @Nullable CommandTeleport.a commandteleport_a) {
+        // Paper start - Don't allow teleport command to invalid locations
+        if (d0 <= -30000000 || d2 <= -30000000 || d0 > 30000000 || d2 > 30000000) { // Copy/pasta from BaseBlockPosition#isValidLocation
+            org.bukkit.Bukkit.getLogger().warning("Refused to teleport " + entity.getName() + " to " + d0 + ", " + d1 + ", " + d2);
+            return;
+        }
+        // Paper end
         if (entity instanceof EntityPlayer) {
             ChunkCoordIntPair chunkcoordintpair = new ChunkCoordIntPair(new BlockPosition(d0, d1, d2));
 
-- 
2.26.0