ipc/ipc_fuzzing_tests.cc - chromium/src - Git at Google

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include <stdint.h>
 #include <stdio.h>

 #include <limits>
 #include <memory>
 #include <sstream>
 #include <string>

 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/platform_thread.h"
 #include "build/build_config.h"
 #include "ipc/ipc_test_base.h"
 #include "testing/gtest/include/gtest/gtest.h"

 // IPC messages for testing ----------------------------------------------------

 #define IPC_MESSAGE_IMPL
 #include "ipc/ipc_message_macros.h"

 #define IPC_MESSAGE_START TestMsgStart

 // Generic message class that is an int followed by a string16.
 IPC_MESSAGE_CONTROL2(MsgClassIS, int, base::string16)

 // Generic message class that is a string16 followed by an int.
 IPC_MESSAGE_CONTROL2(MsgClassSI, base::string16, int)

 // Message to create a mutex in the IPC server, using the received name.
 IPC_MESSAGE_CONTROL2(MsgDoMutex, base::string16, int)

 // Used to generate an ID for a message that should not exist.
 IPC_MESSAGE_CONTROL0(MsgUnhandled)

 // -----------------------------------------------------------------------------

 namespace {

 TEST(IPCMessageIntegrity, ReadBeyondBufferStr) {
   // This was BUG 984408.
   uint32_t v1 = std::numeric_limits<uint32_t>::max() - 1;
   int v2 = 666;
   IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
   EXPECT_TRUE(m.WriteInt(v1));
   EXPECT_TRUE(m.WriteInt(v2));

   base::PickleIterator iter(m);
   std::string vs;
   EXPECT_FALSE(iter.ReadString(&vs));
 }

 TEST(IPCMessageIntegrity, ReadBeyondBufferStr16) {
   // This was BUG 984408.
   uint32_t v1 = std::numeric_limits<uint32_t>::max() - 1;
   int v2 = 777;
   IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
   EXPECT_TRUE(m.WriteInt(v1));
   EXPECT_TRUE(m.WriteInt(v2));

   base::PickleIterator iter(m);
   base::string16 vs;
   EXPECT_FALSE(iter.ReadString16(&vs));
 }

 TEST(IPCMessageIntegrity, ReadBytesBadIterator) {
   // This was BUG 1035467.
   IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
   EXPECT_TRUE(m.WriteInt(1));
   EXPECT_TRUE(m.WriteInt(2));

   base::PickleIterator iter(m);
   const char* data = NULL;
   EXPECT_TRUE(iter.ReadBytes(&data, sizeof(int)));
 }

 TEST(IPCMessageIntegrity, ReadVectorNegativeSize) {
   // A slight variation of BUG 984408. Note that the pickling of vector<char>
   // has a specialized template which is not vulnerable to this bug. So here
   // try to hit the non-specialized case vector<P>.
   IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
   EXPECT_TRUE(m.WriteInt(-1));   // This is the count of elements.
   EXPECT_TRUE(m.WriteInt(1));
   EXPECT_TRUE(m.WriteInt(2));
   EXPECT_TRUE(m.WriteInt(3));

   std::vector<double> vec;
   base::PickleIterator iter(m);
   EXPECT_FALSE(ReadParam(&m, &iter, &vec));
 }

 #if defined(OS_ANDROID)
 #define MAYBE_ReadVectorTooLarge1 DISABLED_ReadVectorTooLarge1
 #else
 #define MAYBE_ReadVectorTooLarge1 ReadVectorTooLarge1
 #endif
 TEST(IPCMessageIntegrity, MAYBE_ReadVectorTooLarge1) {
   // This was BUG 1006367. This is the large but positive length case. Again
   // we try to hit the non-specialized case vector<P>.
   IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
   EXPECT_TRUE(m.WriteInt(0x21000003));   // This is the count of elements.
   EXPECT_TRUE(m.WriteInt64(1));
   EXPECT_TRUE(m.WriteInt64(2));

   std::vector<int64_t> vec;
   base::PickleIterator iter(m);
   EXPECT_FALSE(ReadParam(&m, &iter, &vec));
 }

 TEST(IPCMessageIntegrity, ReadVectorTooLarge2) {
   // This was BUG 1006367. This is the large but positive with an additional
   // integer overflow when computing the actual byte size. Again we try to hit
   // the non-specialized case vector<P>.
   IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
   EXPECT_TRUE(m.WriteInt(0x71000000));   // This is the count of elements.
   EXPECT_TRUE(m.WriteInt64(1));
   EXPECT_TRUE(m.WriteInt64(2));

   std::vector<int64_t> vec;
   base::PickleIterator iter(m);
   EXPECT_FALSE(ReadParam(&m, &iter, &vec));
 }

 class SimpleListener : public IPC::Listener {
  public:
   SimpleListener() : other_(NULL) {
   }
   void Init(IPC::Sender* s) {
     other_ = s;
   }
  protected:
   IPC::Sender* other_;
 };

 enum {
   FUZZER_ROUTING_ID = 5
 };

 // The fuzzer server class. It runs in a child process and expects
 // only two IPC calls; after that it exits the message loop which
 // terminates the child process.
 class FuzzerServerListener : public SimpleListener {
  public:
   FuzzerServerListener() : message_count_(2), pending_messages_(0) {
   }
   bool OnMessageReceived(const IPC::Message& msg) override {
     if (msg.routing_id() == MSG_ROUTING_CONTROL) {
       ++pending_messages_;
       IPC_BEGIN_MESSAGE_MAP(FuzzerServerListener, msg)
         IPC_MESSAGE_HANDLER(MsgClassIS, OnMsgClassISMessage)
         IPC_MESSAGE_HANDLER(MsgClassSI, OnMsgClassSIMessage)
       IPC_END_MESSAGE_MAP()
       if (pending_messages_) {
         // Probably a problem de-serializing the message.
         ReplyMsgNotHandled(msg.type());
       }
     }
     return true;
   }

  private:
   void OnMsgClassISMessage(int value, const base::string16& text) {
     UseData(MsgClassIS::ID, value, text);
     RoundtripAckReply(FUZZER_ROUTING_ID, MsgClassIS::ID, value);
     Cleanup();
   }

   void OnMsgClassSIMessage(const base::string16& text, int value) {
     UseData(MsgClassSI::ID, value, text);
     RoundtripAckReply(FUZZER_ROUTING_ID, MsgClassSI::ID, value);
     Cleanup();
   }

   bool RoundtripAckReply(int routing, uint32_t type_id, int reply) {
     IPC::Message* message = new IPC::Message(routing, type_id,
                                              IPC::Message::PRIORITY_NORMAL);
     message->WriteInt(reply + 1);
     message->WriteInt(reply);
     return other_->Send(message);
   }

   void Cleanup() {
     --message_count_;
     --pending_messages_;
     if (0 == message_count_)
       base::MessageLoop::current()->QuitWhenIdle();
   }

   void ReplyMsgNotHandled(uint32_t type_id) {
     RoundtripAckReply(FUZZER_ROUTING_ID, MsgUnhandled::ID, type_id);
     Cleanup();
   }

   void UseData(int caller, int value, const base::string16& text) {
     std::ostringstream os;
     os << "IPC fuzzer:" << caller << " [" << value << " "
        << base::UTF16ToUTF8(text) << "]\n";
     std::string output = os.str();
     LOG(WARNING) << output;
   }

   int message_count_;
   int pending_messages_;
 };

 class FuzzerClientListener : public SimpleListener {
  public:
   FuzzerClientListener() : last_msg_(NULL) {
   }

   bool OnMessageReceived(const IPC::Message& msg) override {
     last_msg_ = new IPC::Message(msg);
     base::MessageLoop::current()->QuitWhenIdle();
     return true;
   }

   bool ExpectMessage(int value, uint32_t type_id) {
     if (!MsgHandlerInternal(type_id))
       return false;
     int msg_value1 = 0;
     int msg_value2 = 0;
     base::PickleIterator iter(*last_msg_);
     if (!iter.ReadInt(&msg_value1))
       return false;
     if (!iter.ReadInt(&msg_value2))
       return false;
     if ((msg_value2 + 1) != msg_value1)
       return false;
     if (msg_value2 != value)
       return false;

     delete last_msg_;
     last_msg_ = NULL;
     return true;
   }

   bool ExpectMsgNotHandled(uint32_t type_id) {
     return ExpectMessage(type_id, MsgUnhandled::ID);
   }

  private:
   bool MsgHandlerInternal(uint32_t type_id) {
     base::RunLoop().Run();
     if (NULL == last_msg_)
       return false;
     if (FUZZER_ROUTING_ID != last_msg_->routing_id())
       return false;
     return (type_id == last_msg_->type());
   }

   IPC::Message* last_msg_;
 };

 // Runs the fuzzing server child mode. Returns when the preset number of
 // messages have been received.
 DEFINE_IPC_CHANNEL_MOJO_TEST_CLIENT(FuzzServerClient) {
   FuzzerServerListener listener;
   Connect(&listener);
   listener.Init(channel());
   base::RunLoop().Run();
   Close();
 }

 using IPCFuzzingTest = IPCChannelMojoTestBase;

 // This test makes sure that the FuzzerClientListener and FuzzerServerListener
 // are working properly by generating two well formed IPC calls.
 TEST_F(IPCFuzzingTest, SanityTest) {
   Init("FuzzServerClient");

   FuzzerClientListener listener;
   CreateChannel(&listener);
   listener.Init(channel());
   ASSERT_TRUE(ConnectChannel());

   IPC::Message* msg = NULL;
   int value = 43;
   msg = new MsgClassIS(value, base::ASCIIToUTF16("expect 43"));
   sender()->Send(msg);
   EXPECT_TRUE(listener.ExpectMessage(value, MsgClassIS::ID));

   msg = new MsgClassSI(base::ASCIIToUTF16("expect 44"), ++value);
   sender()->Send(msg);
   EXPECT_TRUE(listener.ExpectMessage(value, MsgClassSI::ID));

   EXPECT_TRUE(WaitForClientShutdown());
   DestroyChannel();
 }

 // This test uses a payload that is smaller than expected. This generates an
 // error while unpacking the IPC buffer. Right after we generate another valid
 // IPC to make sure framing is working properly.
 TEST_F(IPCFuzzingTest, MsgBadPayloadShort) {
   Init("FuzzServerClient");

   FuzzerClientListener listener;
   CreateChannel(&listener);
   listener.Init(channel());
   ASSERT_TRUE(ConnectChannel());

   IPC::Message* msg = new IPC::Message(MSG_ROUTING_CONTROL, MsgClassIS::ID,
                                        IPC::Message::PRIORITY_NORMAL);
   msg->WriteInt(666);
   sender()->Send(msg);
   EXPECT_TRUE(listener.ExpectMsgNotHandled(MsgClassIS::ID));

   msg = new MsgClassSI(base::ASCIIToUTF16("expect one"), 1);
   sender()->Send(msg);
   EXPECT_TRUE(listener.ExpectMessage(1, MsgClassSI::ID));

   EXPECT_TRUE(WaitForClientShutdown());
   DestroyChannel();
 }

 // This test uses a payload that has too many arguments, but so the payload size
 // is big enough so the unpacking routine does not generate an error as in the
 // case of MsgBadPayloadShort test. This test does not pinpoint a flaw (per se)
 // as by design we don't carry type information on the IPC message.
 TEST_F(IPCFuzzingTest, MsgBadPayloadArgs) {
   Init("FuzzServerClient");

   FuzzerClientListener listener;
   CreateChannel(&listener);
   listener.Init(channel());
   ASSERT_TRUE(ConnectChannel());

   IPC::Message* msg = new IPC::Message(MSG_ROUTING_CONTROL, MsgClassSI::ID,
                                        IPC::Message::PRIORITY_NORMAL);
   msg->WriteString16(base::ASCIIToUTF16("d"));
   msg->WriteInt(0);
   msg->WriteInt(0x65);  // Extra argument.

   sender()->Send(msg);
   EXPECT_TRUE(listener.ExpectMessage(0, MsgClassSI::ID));

   // Now send a well formed message to make sure the receiver wasn't
   // thrown out of sync by the extra argument.
   msg = new MsgClassIS(3, base::ASCIIToUTF16("expect three"));
   sender()->Send(msg);
   EXPECT_TRUE(listener.ExpectMessage(3, MsgClassIS::ID));

   EXPECT_TRUE(WaitForClientShutdown());
   DestroyChannel();
 }

 }  // namespace
	// Copyright (c) 2012 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include <stdint.h>
	#include <stdio.h>

	#include <limits>
	#include <memory>
	#include <sstream>
	#include <string>

	#include "base/message_loop/message_loop.h"
	#include "base/run_loop.h"
	#include "base/strings/string16.h"
	#include "base/strings/utf_string_conversions.h"
	#include "base/threading/platform_thread.h"
	#include "build/build_config.h"
	#include "ipc/ipc_test_base.h"
	#include "testing/gtest/include/gtest/gtest.h"

	// IPC messages for testing ----------------------------------------------------

	#define IPC_MESSAGE_IMPL
	#include "ipc/ipc_message_macros.h"

	#define IPC_MESSAGE_START TestMsgStart

	// Generic message class that is an int followed by a string16.
	IPC_MESSAGE_CONTROL2(MsgClassIS, int, base::string16)

	// Generic message class that is a string16 followed by an int.
	IPC_MESSAGE_CONTROL2(MsgClassSI, base::string16, int)

	// Message to create a mutex in the IPC server, using the received name.
	IPC_MESSAGE_CONTROL2(MsgDoMutex, base::string16, int)

	// Used to generate an ID for a message that should not exist.
	IPC_MESSAGE_CONTROL0(MsgUnhandled)

	// -----------------------------------------------------------------------------

	namespace {

	TEST(IPCMessageIntegrity, ReadBeyondBufferStr) {
	// This was BUG 984408.
	uint32_t v1 = std::numeric_limits<uint32_t>::max() - 1;
	int v2 = 666;
	IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
	EXPECT_TRUE(m.WriteInt(v1));
	EXPECT_TRUE(m.WriteInt(v2));

	base::PickleIterator iter(m);
	std::string vs;
	EXPECT_FALSE(iter.ReadString(&vs));
	}

	TEST(IPCMessageIntegrity, ReadBeyondBufferStr16) {
	// This was BUG 984408.
	uint32_t v1 = std::numeric_limits<uint32_t>::max() - 1;
	int v2 = 777;
	IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
	EXPECT_TRUE(m.WriteInt(v1));
	EXPECT_TRUE(m.WriteInt(v2));

	base::PickleIterator iter(m);
	base::string16 vs;
	EXPECT_FALSE(iter.ReadString16(&vs));
	}

	TEST(IPCMessageIntegrity, ReadBytesBadIterator) {
	// This was BUG 1035467.
	IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
	EXPECT_TRUE(m.WriteInt(1));
	EXPECT_TRUE(m.WriteInt(2));

	base::PickleIterator iter(m);
	const char* data = NULL;
	EXPECT_TRUE(iter.ReadBytes(&data, sizeof(int)));
	}

	TEST(IPCMessageIntegrity, ReadVectorNegativeSize) {
	// A slight variation of BUG 984408. Note that the pickling of vector<char>
	// has a specialized template which is not vulnerable to this bug. So here
	// try to hit the non-specialized case vector<P>.
	IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
	EXPECT_TRUE(m.WriteInt(-1)); // This is the count of elements.
	EXPECT_TRUE(m.WriteInt(1));
	EXPECT_TRUE(m.WriteInt(2));
	EXPECT_TRUE(m.WriteInt(3));

	std::vector<double> vec;
	base::PickleIterator iter(m);
	EXPECT_FALSE(ReadParam(&m, &iter, &vec));
	}

	#if defined(OS_ANDROID)
	#define MAYBE_ReadVectorTooLarge1 DISABLED_ReadVectorTooLarge1
	#else
	#define MAYBE_ReadVectorTooLarge1 ReadVectorTooLarge1
	#endif
	TEST(IPCMessageIntegrity, MAYBE_ReadVectorTooLarge1) {
	// This was BUG 1006367. This is the large but positive length case. Again
	// we try to hit the non-specialized case vector<P>.
	IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
	EXPECT_TRUE(m.WriteInt(0x21000003)); // This is the count of elements.
	EXPECT_TRUE(m.WriteInt64(1));
	EXPECT_TRUE(m.WriteInt64(2));

	std::vector<int64_t> vec;
	base::PickleIterator iter(m);
	EXPECT_FALSE(ReadParam(&m, &iter, &vec));
	}

	TEST(IPCMessageIntegrity, ReadVectorTooLarge2) {
	// This was BUG 1006367. This is the large but positive with an additional
	// integer overflow when computing the actual byte size. Again we try to hit
	// the non-specialized case vector<P>.
	IPC::Message m(0, 1, IPC::Message::PRIORITY_NORMAL);
	EXPECT_TRUE(m.WriteInt(0x71000000)); // This is the count of elements.
	EXPECT_TRUE(m.WriteInt64(1));
	EXPECT_TRUE(m.WriteInt64(2));

	std::vector<int64_t> vec;
	base::PickleIterator iter(m);
	EXPECT_FALSE(ReadParam(&m, &iter, &vec));
	}

	class SimpleListener : public IPC::Listener {
	public:
	SimpleListener() : other_(NULL) {
	}
	void Init(IPC::Sender* s) {
	other_ = s;
	}
	protected:
	IPC::Sender* other_;
	};

	enum {
	FUZZER_ROUTING_ID = 5
	};

	// The fuzzer server class. It runs in a child process and expects
	// only two IPC calls; after that it exits the message loop which
	// terminates the child process.
	class FuzzerServerListener : public SimpleListener {
	public:
	FuzzerServerListener() : message_count_(2), pending_messages_(0) {
	}
	bool OnMessageReceived(const IPC::Message& msg) override {
	if (msg.routing_id() == MSG_ROUTING_CONTROL) {
	++pending_messages_;
	IPC_BEGIN_MESSAGE_MAP(FuzzerServerListener, msg)
	IPC_MESSAGE_HANDLER(MsgClassIS, OnMsgClassISMessage)
	IPC_MESSAGE_HANDLER(MsgClassSI, OnMsgClassSIMessage)
	IPC_END_MESSAGE_MAP()
	if (pending_messages_) {
	// Probably a problem de-serializing the message.
	ReplyMsgNotHandled(msg.type());
	}
	}
	return true;
	}

	private:
	void OnMsgClassISMessage(int value, const base::string16& text) {
	UseData(MsgClassIS::ID, value, text);
	RoundtripAckReply(FUZZER_ROUTING_ID, MsgClassIS::ID, value);
	Cleanup();
	}

	void OnMsgClassSIMessage(const base::string16& text, int value) {
	UseData(MsgClassSI::ID, value, text);
	RoundtripAckReply(FUZZER_ROUTING_ID, MsgClassSI::ID, value);
	Cleanup();
	}

	bool RoundtripAckReply(int routing, uint32_t type_id, int reply) {
	IPC::Message* message = new IPC::Message(routing, type_id,
	IPC::Message::PRIORITY_NORMAL);
	message->WriteInt(reply + 1);
	message->WriteInt(reply);
	return other_->Send(message);
	}

	void Cleanup() {
	--message_count_;
	--pending_messages_;
	if (0 == message_count_)
	base::MessageLoop::current()->QuitWhenIdle();
	}

	void ReplyMsgNotHandled(uint32_t type_id) {
	RoundtripAckReply(FUZZER_ROUTING_ID, MsgUnhandled::ID, type_id);
	Cleanup();
	}

	void UseData(int caller, int value, const base::string16& text) {
	std::ostringstream os;
	os << "IPC fuzzer:" << caller << " [" << value << " "
	<< base::UTF16ToUTF8(text) << "]\n";
	std::string output = os.str();
	LOG(WARNING) << output;
	}

	int message_count_;
	int pending_messages_;
	};

	class FuzzerClientListener : public SimpleListener {
	public:
	FuzzerClientListener() : last_msg_(NULL) {
	}

	bool OnMessageReceived(const IPC::Message& msg) override {
	last_msg_ = new IPC::Message(msg);
	base::MessageLoop::current()->QuitWhenIdle();
	return true;
	}

	bool ExpectMessage(int value, uint32_t type_id) {
	if (!MsgHandlerInternal(type_id))
	return false;
	int msg_value1 = 0;
	int msg_value2 = 0;
	base::PickleIterator iter(*last_msg_);
	if (!iter.ReadInt(&msg_value1))
	return false;
	if (!iter.ReadInt(&msg_value2))
	return false;
	if ((msg_value2 + 1) != msg_value1)
	return false;
	if (msg_value2 != value)
	return false;

	delete last_msg_;
	last_msg_ = NULL;
	return true;
	}

	bool ExpectMsgNotHandled(uint32_t type_id) {
	return ExpectMessage(type_id, MsgUnhandled::ID);
	}

	private:
	bool MsgHandlerInternal(uint32_t type_id) {
	base::RunLoop().Run();
	if (NULL == last_msg_)
	return false;
	if (FUZZER_ROUTING_ID != last_msg_->routing_id())
	return false;
	return (type_id == last_msg_->type());
	}

	IPC::Message* last_msg_;
	};

	// Runs the fuzzing server child mode. Returns when the preset number of
	// messages have been received.
	DEFINE_IPC_CHANNEL_MOJO_TEST_CLIENT(FuzzServerClient) {
	FuzzerServerListener listener;
	Connect(&listener);
	listener.Init(channel());
	base::RunLoop().Run();
	Close();
	}

	using IPCFuzzingTest = IPCChannelMojoTestBase;

	// This test makes sure that the FuzzerClientListener and FuzzerServerListener
	// are working properly by generating two well formed IPC calls.
	TEST_F(IPCFuzzingTest, SanityTest) {
	Init("FuzzServerClient");

	FuzzerClientListener listener;
	CreateChannel(&listener);
	listener.Init(channel());
	ASSERT_TRUE(ConnectChannel());

	IPC::Message* msg = NULL;
	int value = 43;
	msg = new MsgClassIS(value, base::ASCIIToUTF16("expect 43"));
	sender()->Send(msg);
	EXPECT_TRUE(listener.ExpectMessage(value, MsgClassIS::ID));

	msg = new MsgClassSI(base::ASCIIToUTF16("expect 44"), ++value);
	sender()->Send(msg);
	EXPECT_TRUE(listener.ExpectMessage(value, MsgClassSI::ID));

	EXPECT_TRUE(WaitForClientShutdown());
	DestroyChannel();
	}

	// This test uses a payload that is smaller than expected. This generates an
	// error while unpacking the IPC buffer. Right after we generate another valid
	// IPC to make sure framing is working properly.
	TEST_F(IPCFuzzingTest, MsgBadPayloadShort) {
	Init("FuzzServerClient");

	FuzzerClientListener listener;
	CreateChannel(&listener);
	listener.Init(channel());
	ASSERT_TRUE(ConnectChannel());

	IPC::Message* msg = new IPC::Message(MSG_ROUTING_CONTROL, MsgClassIS::ID,
	IPC::Message::PRIORITY_NORMAL);
	msg->WriteInt(666);
	sender()->Send(msg);
	EXPECT_TRUE(listener.ExpectMsgNotHandled(MsgClassIS::ID));

	msg = new MsgClassSI(base::ASCIIToUTF16("expect one"), 1);
	sender()->Send(msg);
	EXPECT_TRUE(listener.ExpectMessage(1, MsgClassSI::ID));

	EXPECT_TRUE(WaitForClientShutdown());
	DestroyChannel();
	}

	// This test uses a payload that has too many arguments, but so the payload size
	// is big enough so the unpacking routine does not generate an error as in the
	// case of MsgBadPayloadShort test. This test does not pinpoint a flaw (per se)
	// as by design we don't carry type information on the IPC message.
	TEST_F(IPCFuzzingTest, MsgBadPayloadArgs) {
	Init("FuzzServerClient");

	FuzzerClientListener listener;
	CreateChannel(&listener);
	listener.Init(channel());
	ASSERT_TRUE(ConnectChannel());

	IPC::Message* msg = new IPC::Message(MSG_ROUTING_CONTROL, MsgClassSI::ID,
	IPC::Message::PRIORITY_NORMAL);
	msg->WriteString16(base::ASCIIToUTF16("d"));
	msg->WriteInt(0);
	msg->WriteInt(0x65); // Extra argument.

	sender()->Send(msg);
	EXPECT_TRUE(listener.ExpectMessage(0, MsgClassSI::ID));

	// Now send a well formed message to make sure the receiver wasn't
	// thrown out of sync by the extra argument.
	msg = new MsgClassIS(3, base::ASCIIToUTF16("expect three"));
	sender()->Send(msg);
	EXPECT_TRUE(listener.ExpectMessage(3, MsgClassIS::ID));

	EXPECT_TRUE(WaitForClientShutdown());
	DestroyChannel();
	}

	} // namespace