1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136


mojo / core / channel_mac_fuzzer.cc [blame]

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <list>

#include "base/apple/mach_logging.h"
#include "base/logging.h"
#include "base/message_loop/message_pump_type.h"
#include "base/run_loop.h"
#include "base/task/single_thread_task_executor.h"
#include "base/task/single_thread_task_runner.h"
#include "mojo/core/channel.h"
#include "mojo/core/entrypoints.h"
#include "mojo/core/ipcz_driver/envelope.h"
#include "mojo/core/test/data/channel_mac/channel_mac.pb.h"
#include "mojo/public/cpp/platform/platform_channel.h"
#include "testing/libfuzzer/fuzzers/mach/mach_message_converter.h"
#include "testing/libfuzzer/proto/lpm_interface.h"

namespace {

class ChannelMacFuzzer {
 public:
  ChannelMacFuzzer() {
    mojo::core::InitializeCore();

    logging::SetMinLogLevel(logging::LOGGING_FATAL);
  }

  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner() {
    return io_task_executor_.task_runner();
  }

 private:
  base::SingleThreadTaskExecutor io_task_executor_{base::MessagePumpType::IO};
};

class FakeChannelDelegate : public mojo::core::Channel::Delegate {
 public:
  FakeChannelDelegate() = default;
  ~FakeChannelDelegate() override = default;

  void OnChannelMessage(
      const void* payload,
      size_t payload_size,
      std::vector<mojo::PlatformHandle> handles,
      scoped_refptr<mojo::core::ipcz_driver::Envelope> envelope) override {}
  void OnChannelError(mojo::core::Channel::Error error) override {}
};

}  // namespace

DEFINE_BINARY_PROTO_FUZZER(mojo_fuzzer::ChannelMac proto) {
  static ChannelMacFuzzer environment;

  mojo::PlatformChannel platform_channel;
  mojo::PlatformChannelEndpoint fuzzed_endpoint;
  mojo::PlatformChannelEndpoint other_endpoint;

  mach_port_t send_port = platform_channel.local_endpoint()
                              .platform_handle()
                              .GetMachSendRight()
                              .get();

  if (proto.endpoint_type() == mojo_fuzzer::ChannelMac_EndpointType_LOCAL) {
    fuzzed_endpoint = platform_channel.TakeLocalEndpoint();
    other_endpoint = platform_channel.TakeRemoteEndpoint();
  } else if (proto.endpoint_type() ==
             mojo_fuzzer::ChannelMac_EndpointType_REMOTE) {
    fuzzed_endpoint = platform_channel.TakeRemoteEndpoint();
    other_endpoint = platform_channel.TakeLocalEndpoint();
  }

  FakeChannelDelegate delegate;

  auto channel = mojo::core::Channel::Create(
      &delegate, mojo::core::ConnectionParams(std::move(fuzzed_endpoint)),
      mojo::core::Channel::HandlePolicy::kAcceptHandles,
      environment.io_task_runner());
  channel->Start();

  // If the handshake is not being fuzzed, establish a peer Channel that will
  // put |channel| into a good state by performing the handshake.
  scoped_refptr<mojo::core::Channel> peer_channel;
  if (!proto.fuzz_handshake()) {
    peer_channel = mojo::core::Channel::Create(
        &delegate, mojo::core::ConnectionParams(std::move(other_endpoint)),
        mojo::core::Channel::HandlePolicy::kAcceptHandles,
        environment.io_task_runner());
    peer_channel->Start();
  }

  base::RunLoop().RunUntilIdle();

  // Save off any ports that were sent as part of a message until after the
  // channel has been shut down.
  std::list<mach_fuzzer::SendablePort> ports_to_destroy;

  for (auto& message : *proto.mutable_messages()) {
    if (message.HasExtension(mojo_fuzzer::MojoMessage::mojo_message)) {
      // Mojo message data for inline Mach messages is
      // [data_length_uint64][data_bytes].
      const auto& mojo_message =
          message.GetExtension(mojo_fuzzer::MojoMessage::mojo_message);

      // If the fuzz data do not specify an explicit length, just use the byte
      // length.
      uint64_t data_length = mojo_message.has_data_length()
                                 ? mojo_message.data_length()
                                 : mojo_message.data().size();
      std::string data;
      data.append(reinterpret_cast<const char*>(&data_length),
                  sizeof(data_length));
      data.append(mojo_message.data().begin(), mojo_message.data().end());
      message.set_data(data);
    }

    mach_fuzzer::SendResult result = SendMessage(send_port, message);

    std::move(result.message.ports.begin(), result.message.ports.end(),
              std::back_inserter(ports_to_destroy));
  }

  base::RunLoop().RunUntilIdle();

  channel->ShutDown();
  channel.reset();

  if (peer_channel) {
    peer_channel->ShutDown();
    peer_channel.reset();
  }

  base::RunLoop().RunUntilIdle();
}