Paper/patches/server/0951-Validate-ResourceLocation-in-NBT-reading.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Nassim Jahnke <nassim@njahnke.dev>
Date: Thu, 4 Jan 2024 13:49:14 +0100
Subject: [PATCH] Validate ResourceLocation in NBT reading


diff --git a/src/main/java/net/minecraft/nbt/NbtUtils.java b/src/main/java/net/minecraft/nbt/NbtUtils.java
index 1d7c20fe14882fdeddf315a8923669e3385652f5..f88dd37783b3c155c23b547c360b8d3c16e030c0 100644
--- a/src/main/java/net/minecraft/nbt/NbtUtils.java
+++ b/src/main/java/net/minecraft/nbt/NbtUtils.java
@@ -149,8 +149,10 @@ public final class NbtUtils {
         if (!nbt.contains("Name", 8)) {
             return Blocks.AIR.defaultBlockState();
         } else {
-            ResourceLocation resourceLocation = new ResourceLocation(nbt.getString("Name"));
-            Optional<? extends Holder<Block>> optional = blockLookup.get(ResourceKey.create(Registries.BLOCK, resourceLocation));
+            // Paper start - Validate resource location
+            ResourceLocation resourceLocation = ResourceLocation.tryParse(nbt.getString("Name"));
+            Optional<? extends Holder<Block>> optional = resourceLocation != null ? blockLookup.get(ResourceKey.create(Registries.BLOCK, resourceLocation)) : Optional.empty();
+            // Paper end - Validate resource location
             if (optional.isEmpty()) {
                 return Blocks.AIR.defaultBlockState();
             } else {
diff --git a/src/main/java/net/minecraft/resources/ResourceLocation.java b/src/main/java/net/minecraft/resources/ResourceLocation.java
index d93b623ce973b63d4f3a77bfe459f51af7cb3c1c..2c4553312f2f37f8613ac813708b4b95f9675e9f 100644
--- a/src/main/java/net/minecraft/resources/ResourceLocation.java
+++ b/src/main/java/net/minecraft/resources/ResourceLocation.java
@@ -37,6 +37,13 @@ public class ResourceLocation implements Comparable<ResourceLocation> {
     private final String path;
 
     protected ResourceLocation(String namespace, String path, @Nullable ResourceLocation.Dummy extraData) {
+        // Paper start - Validate ResourceLocation
+        // Check for the max network string length (capped at Short.MAX_VALUE) as well as the max bytes of a StringTag (length written as an unsigned short)
+        final String resourceLocation = namespace + ":" + path;
+        if (resourceLocation.length() > Short.MAX_VALUE || io.netty.buffer.ByteBufUtil.utf8MaxBytes(resourceLocation) > 2 * Short.MAX_VALUE + 1) {
+            throw new ResourceLocationException("Resource location too long: " + resourceLocation);
+        }
+        // Paper end - Validate ResourceLocation
         this.namespace = namespace;
         this.path = path;
     }
diff --git a/src/main/java/net/minecraft/world/entity/EntityType.java b/src/main/java/net/minecraft/world/entity/EntityType.java
index 066c7033fdd9506a0edc5f5a0ec3bb1f1fbae336..d2503224a1697636b3f9c26126d6bb201143076a 100644
--- a/src/main/java/net/minecraft/world/entity/EntityType.java
+++ b/src/main/java/net/minecraft/world/entity/EntityType.java
@@ -623,7 +623,7 @@ public class EntityType<T extends Entity> implements FeatureElement, EntityTypeT
     }
 
     public static Optional<EntityType<?>> by(CompoundTag nbt) {
-        return BuiltInRegistries.ENTITY_TYPE.getOptional(new ResourceLocation(nbt.getString("id")));
+        return BuiltInRegistries.ENTITY_TYPE.getOptional(ResourceLocation.tryParse(nbt.getString("id"))); // Paper - Validate ResourceLocation
     }
 
     @Nullable
diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index 68c312dc39ef6fdb88e201ba096c9bd99aebddd7..0416af1342dad6a6789aa743aadf61b32b70f338 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -911,12 +911,13 @@ public abstract class LivingEntity extends Entity implements Attackable {
 
         if (nbt.contains("SleepingX", 99) && nbt.contains("SleepingY", 99) && nbt.contains("SleepingZ", 99)) {
             BlockPos blockposition = new BlockPos(nbt.getInt("SleepingX"), nbt.getInt("SleepingY"), nbt.getInt("SleepingZ"));
-
+            if (this.position().distanceToSqr(blockposition.getX(), blockposition.getY(), blockposition.getZ()) < 16 * 16) { // Paper - The sleeping pos will always also set the actual pos, so a desync suggests something is wrong
             this.setSleepingPos(blockposition);
             this.entityData.set(LivingEntity.DATA_POSE, Pose.SLEEPING);
             if (!this.firstTick) {
                 this.setPosToBed(blockposition);
             }
+            } // Paper - The sleeping pos will always also set the actual pos, so a desync suggests something is wrong
         }
 
         if (nbt.contains("Brain", 10)) {
diff --git a/src/main/java/net/minecraft/world/entity/Mob.java b/src/main/java/net/minecraft/world/entity/Mob.java
index 506101a692c73f6acf2e647c3ab18024ccdff866..4f2148d13fc26ad2c43460f46c376832c1bb8150 100644
--- a/src/main/java/net/minecraft/world/entity/Mob.java
+++ b/src/main/java/net/minecraft/world/entity/Mob.java
@@ -642,7 +642,7 @@ public abstract class Mob extends LivingEntity implements EquipmentUser, Targeti
 
         this.setLeftHanded(nbt.getBoolean("LeftHanded"));
         if (nbt.contains("DeathLootTable", 8)) {
-            this.lootTable = ResourceKey.create(Registries.LOOT_TABLE, new ResourceLocation(nbt.getString("DeathLootTable")));
+            this.lootTable = net.minecraft.Optionull.map(ResourceLocation.tryParse(nbt.getString("DeathLootTable")), rl -> ResourceKey.create(Registries.LOOT_TABLE, rl)); // Paper - Validate ResourceLocation
             this.lootTableSeed = nbt.getLong("DeathLootTableSeed");
         }
 
diff --git a/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java b/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java
index 2df84bc367f650c3d468e0f09ed565e68de43a82..7ea5f496dc9ffab8311fcc79de47362a66c703e6 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java
@@ -556,7 +556,7 @@ public abstract class AbstractArrow extends Projectile {
         this.setCritArrow(nbt.getBoolean("crit"));
         this.setPierceLevel(nbt.getByte("PierceLevel"));
         if (nbt.contains("SoundEvent", 8)) {
-            this.soundEvent = (SoundEvent) BuiltInRegistries.SOUND_EVENT.getOptional(new ResourceLocation(nbt.getString("SoundEvent"))).orElse(this.getDefaultHitGroundSoundEvent());
+            this.soundEvent = (SoundEvent) BuiltInRegistries.SOUND_EVENT.getOptional(ResourceLocation.tryParse(nbt.getString("SoundEvent"))).orElse(this.getDefaultHitGroundSoundEvent()); // Paper - Validate resource location
         }
 
         this.setShotFromCrossbow(nbt.getBoolean("ShotFromCrossbow"));
diff --git a/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java b/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java
index f33e5cf6d456e615050047e924d9b24268a2c51e..c660e9b1e9635011b32fa19cf64118d64408f158 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java
@@ -72,7 +72,7 @@ public interface ContainerEntity extends Container, MenuProvider {
     default void readChestVehicleSaveData(CompoundTag nbt, HolderLookup.Provider registriesLookup) {
         this.clearItemStacks();
         if (nbt.contains("LootTable", 8)) {
-            this.setLootTable(ResourceKey.create(Registries.LOOT_TABLE, new ResourceLocation(nbt.getString("LootTable"))));
+            this.setLootTable(net.minecraft.Optionull.map(ResourceLocation.tryParse(nbt.getString("LootTable")), rl -> ResourceKey.create(Registries.LOOT_TABLE, rl))); // Paper - Validate ResourceLocation
             this.setLootTableSeed(nbt.getLong("LootTableSeed"));
         }
         ContainerHelper.loadAllItems(nbt, this.getItemStacks(), registriesLookup); // Paper - always save the items, table may still remain
diff --git a/src/main/java/net/minecraft/world/level/block/entity/AbstractFurnaceBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/AbstractFurnaceBlockEntity.java
index f40b2582d9087f9dbb5cab950304698f33fdd879..a99fe191c429bb528209dd0f31b509acf9cccbb5 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/AbstractFurnaceBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/AbstractFurnaceBlockEntity.java
@@ -295,7 +295,12 @@ public abstract class AbstractFurnaceBlockEntity extends BaseContainerBlockEntit
         while (iterator.hasNext()) {
             String s = (String) iterator.next();
 
-            this.recipesUsed.put(new ResourceLocation(s), nbttagcompound1.getInt(s));
+            // Paper start - Validate ResourceLocation
+            final ResourceLocation resourceLocation = ResourceLocation.tryParse(s);
+            if (resourceLocation != null) {
+            this.recipesUsed.put(resourceLocation, nbttagcompound1.getInt(s));
+            }
+            // Paper end - Validate ResourceLocation
         }
 
         // Paper start - cook speed multiplier API
diff --git a/src/main/java/net/minecraft/world/level/block/entity/BrushableBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/BrushableBlockEntity.java
index f78a9698afc87408fc46de2d3d00c923500885f4..dc02a3d84b397f634f77f4df9c06e245cc4dcb75 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/BrushableBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/BrushableBlockEntity.java
@@ -202,7 +202,7 @@ public class BrushableBlockEntity extends BlockEntity {
 
     private boolean tryLoadLootTable(CompoundTag nbt) {
         if (nbt.contains("LootTable", 8)) {
-            this.lootTable = ResourceKey.create(Registries.LOOT_TABLE, new ResourceLocation(nbt.getString("LootTable")));
+            this.lootTable = net.minecraft.Optionull.map(ResourceLocation.tryParse(nbt.getString("LootTable")), rl -> ResourceKey.create(Registries.LOOT_TABLE, rl)); // Paper - Validate ResourceLocation
             this.lootTableSeed = nbt.getLong("LootTableSeed");
             return true;
         } else {