PaperMC/patches/server/0973-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 f3b11b08358fdd93464cd19b05047e10727a5799..c192ddee39afe1de0b5454bc94593b10fefbb24d 100644
--- a/src/main/java/net/minecraft/nbt/NbtUtils.java
+++ b/src/main/java/net/minecraft/nbt/NbtUtils.java
@@ -222,8 +222,10 @@ 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 3908f88959e43d2f485d5f239257e6564dbda6cd..b549f65d0e276a5ed5b8b2f6956268d05910724f 100644
--- a/src/main/java/net/minecraft/resources/ResourceLocation.java
+++ b/src/main/java/net/minecraft/resources/ResourceLocation.java
@@ -33,6 +33,13 @@ 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 8ba573bb4099ee5b27b61f333e72d794c48d5f29..69bdf3f2ee731e59e8d454816a9ca72cb49c0fe0 100644
--- a/src/main/java/net/minecraft/world/entity/EntityType.java
+++ b/src/main/java/net/minecraft/world/entity/EntityType.java
@@ -614,7 +614,7 @@ 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 bb52d084637c97d9cc1ebaeec28358a0ddb3952b..40e21effc948b02874a6ed1d1c340c4dc87579d6 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -879,12 +879,13 @@ 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 544e22f569d7ddeb1ba46a9ef7f4d4d6ca37c431..d2f5d959d3b67f7c20d0c0de462a18d667f3a84b 100644
--- a/src/main/java/net/minecraft/world/entity/Mob.java
+++ b/src/main/java/net/minecraft/world/entity/Mob.java
@@ -608,7 +608,7 @@ public abstract class Mob extends LivingEntity implements Targeting {
 
         this.setLeftHanded(nbt.getBoolean("LeftHanded"));
         if (nbt.contains("DeathLootTable", 8)) {
-            this.lootTable = new ResourceLocation(nbt.getString("DeathLootTable"));
+            this.lootTable = ResourceLocation.tryParse(nbt.getString("DeathLootTable")); // 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 c30f19162e33dbe8f018b7dc66210681b6027389..e8faca6e443239968f0111519f9e5cd018ed3297 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java
@@ -561,7 +561,7 @@ 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 f4ad1eea5bced6997edbc3a5ed1360b12b70f68f..648eefb973a4e5e543818c417a6ee39f283ea361 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java
@@ -66,7 +66,7 @@ public interface ContainerEntity extends Container, MenuProvider {
     default void readChestVehicleSaveData(CompoundTag nbt) {
         this.clearItemStacks();
         if (nbt.contains("LootTable", 8)) {
-            this.setLootTable(new ResourceLocation(nbt.getString("LootTable")));
+            this.setLootTable(ResourceLocation.tryParse(nbt.getString("LootTable"))); // Paper - Validate ResourceLocation
             this.setLootTableSeed(nbt.getLong("LootTableSeed"));
         }
         ContainerHelper.loadAllItems(nbt, this.getItemStacks()); // Paper - always load 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 d04fc84eef11adb5ea64077f48794b6ed7fb3ada..89d06253b00604114e543ebbe12a9993ae95dc41 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
@@ -290,7 +290,12 @@ 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 b5b1831631e233a96b6fd55972a8862b0f420da8..3f62e823bf9b5aa696e3c240613a0fb50340875e 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
@@ -199,7 +199,7 @@ public class BrushableBlockEntity extends BlockEntity {
 
     private boolean tryLoadLootTable(CompoundTag nbt) {
         if (nbt.contains("LootTable", 8)) {
-            this.lootTable = new ResourceLocation(nbt.getString("LootTable"));
+            this.lootTable = ResourceLocation.tryParse(nbt.getString("LootTable")); // Paper - Validate ResourceLocation
             this.lootTableSeed = nbt.getLong("LootTableSeed");
             return true;
         } else {