  void Initialized(mojo::ScopedSharedBufferHandle shared_buffer,
                   mojo::ScopedHandle socket_handle,
                   bool initially_muted) {
    ASSERT_TRUE(shared_buffer.is_valid());
    ASSERT_TRUE(socket_handle.is_valid());

    base::PlatformFile fd;
    mojo::UnwrapPlatformFile(std::move(socket_handle), &fd);
    socket_ = std::make_unique<base::CancelableSyncSocket>(fd);
    EXPECT_NE(socket_->handle(), base::CancelableSyncSocket::kInvalidHandle);
 
     size_t memory_length;
     base::SharedMemoryHandle shmem_handle;
    mojo::UnwrappedSharedMemoryHandleProtection protection;
     EXPECT_EQ(
         mojo::UnwrapSharedMemoryHandle(std::move(shared_buffer), &shmem_handle,
                                       &memory_length, &protection),
         MOJO_RESULT_OK);
    EXPECT_EQ(protection,
              mojo::UnwrappedSharedMemoryHandleProtection::kReadOnly);
    buffer_ = std::make_unique<base::SharedMemory>(shmem_handle,
                                                   true /* read_only */);
 
     GotNotification(initially_muted);
   }

The product writes data past the end, or before the beginning, of the intended buffer.