HasNullPropertyOrFields.cs

void Main()
{
	var obj = new object();
	HasNullPropertyOrFields(obj).Dump();
}

const BindingFlags flags = BindingFlags.Instance | BindingFlags.Public;
bool HasNullPropertyOrFields(object obj)
{
	var visited = new HashSet<object>(ReferenceEqualityComparer.Instance);
	return HasNullPropertyOrFieldsImpl(visited, obj);
}

bool HasNullPropertyOrFieldsImpl(HashSet<object> visited, object obj)
{
	if (obj == null)
		return true;
	var type = obj.GetType();
	if(type.IsClass && !visited.Add(obj))
		return false;
	var properties = type.GetProperties(flags).Select(p => new { Type = p.PropertyType, Values = GetValues(p.GetValue(obj)) });
	var fields = type.GetFields(flags).Select(p => new { Type = p.FieldType, Values = GetValues(p.GetValue(obj)) });
	var members = properties.Concat(fields).ToList();
	return members.Any(m => m.Values == null || m.Values.Any(v => v == null))
		|| members.Any(m => m.Values.Any(HasNullPropertyOrFields));
}

IReadOnlyCollection<object> GetValues(object obj)
{
	if(obj == null)
		return null;
	var seq = obj as IEnumerable;
	if (seq != null)
	{
		var count = TryGetCollectionCount(seq);
		var values = count.HasValue && count.Value >= 0 ? new List<object>(count.Value)	: new List<object>();
		var enumerator = seq.GetEnumerator();
		if(enumerator != null)
			while(enumerator.MoveNext())
				values.Add(enumerator.Current);
		return values;
	}
	else
		return new[] { obj };
}

int? TryGetCollectionCount(IEnumerable seq)
{
	var collection = seq as ICollection;
	if(collection != null)
		return collection.Count;
	return null;
}

public class ReferenceEqualityComparer :  IEqualityComparer<object>
{
	public static readonly ReferenceEqualityComparer Instance = new ReferenceEqualityComparer();
	bool IEqualityComparer<object>.Equals(object x, object y)
	{
		return ReferenceEquals(x, y);
	}
	public int GetHashCode(object obj)
	{
		return RuntimeHelpers.GetHashCode(obj);
	}
}