PaperMC/patches/server/0398-Do-not-accept-invalid-client-settings.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Sat, 7 May 2022 14:58:53 -0700
Subject: [PATCH] Do not accept invalid client settings


diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 18c7189725cc7c2d4438ea711fd72b752d0db0e0..22d6c914ffbe591d3de19b89a0e87d1042bf1772 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -3157,6 +3157,13 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
     @Override
     public void handleClientInformation(ServerboundClientInformationPacket packet) {
         PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
+        // Paper start - do not accept invalid information
+        if (packet.information().viewDistance() < 0) {
+            LOGGER.warn("Disconnecting " + this.player.getScoreboardName() + " for invalid view distance: " + packet.information().viewDistance());
+            this.disconnect("Invalid client settings", org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_ACTION);
+            return;
+        }
+        // Paper end - do not accept invalid information
         this.player.updateOptions(packet.information());
         this.connection.channel.attr(io.papermc.paper.adventure.PaperAdventure.LOCALE_ATTRIBUTE).set(net.kyori.adventure.translation.Translator.parseLocale(packet.information().language())); // Paper
     }