Merge branch 'cassandra-4.1' into cassandra-5.0

* cassandra-4.1:
  Bound declared value length against readable bytes in CBUtil

CHANGES.txt

@@ -12,6 +12,7 @@
 Merged from 4.1:
  * Add Paxos v2 option and informatin in cassandra.yaml (CASSANDRA-21316)
 Merged from 4.0:
+ * Bound declared value length against readable bytes in CBUtil (CASSANDRA-21521)
  * Verify extension type before initializing reflectively-loaded classes (CASSANDRA-21525)
  * Rename conflicting nodetool import --copy-data short option from -p to -cd (CASSANDRA-20214)
  * Fix PasswordObfuscator failing to obfuscate certain passwords (CASSANDRA-21113)

src/java/org/apache/cassandra/transport/CBUtil.java

@@ -454,6 +454,9 @@ public abstract class CBUtil
         int length = cb.readInt();
         if (length < 0)
             return null;
+        if (length > cb.readableBytes())
+            throw new ProtocolException(String.format("Cannot read value of length %d, only %d bytes remaining in the message",
+                                                      length, cb.readableBytes()));
 
         ByteBuffer buffer = cb.nioBuffer(cb.readerIndex(), length);
         cb.skipBytes(length);
@@ -660,6 +663,9 @@ public abstract class CBUtil
 
     private static byte[] readRawBytes(ByteBuf cb, int length)
     {
+        if (length > cb.readableBytes())
+            throw new ProtocolException(String.format("Cannot read value of length %d, only %d bytes remaining in the message",
+                                                      length, cb.readableBytes()));
         byte[] bytes = new byte[length];
         cb.readBytes(bytes);
         return bytes;

test/unit/org/apache/cassandra/transport/CBUtilReadValueNativeProtocolTest.java

@@ -0,0 +1,156 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.cassandra.transport;
+
+import java.util.Objects;
+
+import org.assertj.core.api.Assertions;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import org.apache.cassandra.service.QueryState;
+import org.apache.cassandra.transport.messages.ErrorMessage;
+import org.apache.cassandra.transport.messages.OptionsMessage;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+
+/**
+ * If a client sends an AUTH_RESPONSE whose declared SASL-token length is {@link Integer#MAX_VALUE},
+ * {@link CBUtil#readValue(ByteBuf)} must reject it against the readable byte count rather than
+ * attempting the allocation.
+ * <p>
+ * This reproduces a pre-authentication unbounded-allocation DoS: on unpatched code the read
+ * allocates {@code new byte[Integer.MAX_VALUE]} and the JVM throws OutOfMemoryError; on fixed
+ * code the client receives an ERROR containing "Cannot read value of length 2147483647" and the
+ * server keeps running. The V4 (pre-V5) decoder path is the one the original report exercised.
+ */
+public class CBUtilReadValueNativeProtocolTest extends NativeProtocolLimitsTestBase
+{
+    public CBUtilReadValueNativeProtocolTest()
+    {
+        // V4 / pre-V5 path is the one the report and the reproducer netcat PoC exercise.
+        super(ProtocolVersion.V4);
+    }
+
+    @BeforeClass
+    public static void setUp()
+    {
+        requireNetwork();
+    }
+
+    @Test
+    public void authResponseWithUnboundedTokenLengthIsRejected()
+    {
+        ByteBuf maliciousBody = Unpooled.buffer(4);
+        maliciousBody.writeInt(Integer.MAX_VALUE); // 0x7f ff ff ff
+
+        try (SimpleClient client = client())
+        {
+            Message.Response response = client.execute(new CustomBodyMessage(Message.Type.AUTH_RESPONSE,
+                                                                             maliciousBody),
+                                                       false);
+
+            Assertions.assertThat(response.type)
+                      .as("Server must respond with an ERROR for the malformed AUTH_RESPONSE")
+                      .isEqualTo(Message.Type.ERROR);
+            Assertions.assertThat(((ErrorMessage) response).error.getMessage())
+                      .as("ERROR payload must reference the CBUtil bound check, not OutOfMemoryError")
+                      .contains("Cannot read value of length 2147483647");
+
+            // Sanity-check the server is still alive after the malicious frame: a fresh
+            // OPTIONS roundtrip on a new connection should succeed.
+            try (SimpleClient probe = client())
+            {
+                Message.Response options = probe.execute(new OptionsMessage(), true);
+                Assertions.assertThat(options.type).isEqualTo(Message.Type.SUPPORTED);
+            }
+        }
+    }
+
+    /**
+     * Replaces AUTH_RESPONSE's encoder with one that writes a caller-supplied raw body, so
+     * SimpleClient transmits exactly the bytes we want for the test. The server still uses
+     * the original AuthResponse.Codec.decode on receive, which is what we want — that's the
+     * code path under test.
+     */
+    private static final class CustomBodyMessage extends Message.Request
+    {
+        private final ByteBuf body;
+
+        CustomBodyMessage(Message.Type type, ByteBuf body)
+        {
+            super(type);
+            this.body = Objects.requireNonNull(body);
+        }
+
+        @Override
+        public Envelope encode(ProtocolVersion version, int streamId)
+        {
+            Message.Codec<?> originalCodec = type.codec;
+            try
+            {
+                setCodec(type, new Message.Codec<>()
+                {
+                    @Override
+                    public Message decode(ByteBuf in, ProtocolVersion v)
+                    {
+                        return originalCodec.decode(in, v);
+                    }
+
+                    @Override
+                    public void encode(Message message, ByteBuf dest, ProtocolVersion v)
+                    {
+                        dest.writeBytes(body, body.readerIndex(), body.readableBytes());
+                    }
+
+                    @Override
+                    public int encodedSize(Message message, ProtocolVersion v)
+                    {
+                        return body.readableBytes();
+                    }
+                });
+                return super.encode(version, streamId);
+            }
+            finally
+            {
+                setCodec(type, originalCodec);
+            }
+        }
+
+        @Override
+        protected Message.Response execute(QueryState queryState,
+                                           Dispatcher.RequestTime requestTime,
+                                           boolean traceRequest)
+        {
+            throw new AssertionError("execute not expected for a malformed AUTH_RESPONSE");
+        }
+    }
+
+    private static void setCodec(Message.Type type, Message.Codec<?> codec)
+    {
+        try
+        {
+            type.unsafeSetCodec(codec);
+        }
+        catch (NoSuchFieldException | IllegalAccessException e)
+        {
+            throw new AssertionError(e);
+        }
+    }
+}