Crash due to Stack Overflow when using the DropDownDataGrid property "AllowFilteringByWord" with large amounts of text in filter

mvoxland · June 5, 2025, 8:59pm

Hello,

I noticed this niche but really bad bug accidentally. I had a large amount of text in my clipboard and pasted it into a RadzenDropDownDataGrid's filter box by mistake. This caused a complete crash of the running process, and since it was an InteractiveServer solution it took down the whole website.

To reproduce:

Go to the DropDownDataGrid's demo page and change one of the examples to have AllowFilteringByWord="true"
Paste in a large block of text into the DropDownDataGrid's filter box. Mine had around 40,000 works in it, though I would imagine it still crashes at less than that.
The process running the page crashes completely.

I tracked down the problem, and it only occurs when using the "AllowFilteringByWord" property. I assume the issue is that the query being built just gets too long after having thousands of where clauses added to it, and that the solution would be to limit the amount of times those for loops can be run (see GitHub code below). I thought I would run it by the forum here to see if there are better solutions though.

github.com/radzenhq/radzen-blazor

Radzen.Blazor/RadzenDropDownDataGrid.razor.cs

master


      
          if (AllowFilteringByAllStringColumns && grid != null)
          {
              if (AllowFilteringByWord)
              {
                  string[] words = searchText.Split(' ');
          
                  foreach (string word in words)
                  {
                      query = query.Where(grid.ColumnsCollection.Where(c => c.Filterable && IsColumnFilterPropertyTypeString(c))
                          .Select(c => new FilterDescriptor() { Property = c.GetFilterProperty(), FilterValue = word, FilterOperator = filterOperator }), 
                              LogicalFilterOperator.Or, FilterCaseSensitivity);
                  }
              }
              else
              {
                  query = query.Where(grid.ColumnsCollection.Where(c => c.Filterable && IsColumnFilterPropertyTypeString(c))
                      .Select(c => new FilterDescriptor() { Property = c.GetFilterProperty(), FilterValue = searchText, FilterOperator = filterOperator }), 
                          LogicalFilterOperator.Or, FilterCaseSensitivity);
              }
          }

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Thanks for the help!

enchev · June 6, 2025, 7:08am

This will help with our next update:

mvoxland · June 6, 2025, 5:38pm

Thanks for the quick response!

This does seem to be a good solution to the problem. However for two suggestions:

I think the new AllowFilteringByWordCount should have a default value. That way users can’t accidentally have this crash by neglecting to set it or updating from older versions. It can be something reasonable like 10 or 50, or even quite large if you can find a large amount of words that works without crashing. It doesn’t really matter what it is, I just think it should have a default value.
Shouldn’t the application of the new AllowFilteringByWordCount also be added to line 510?

github.com/radzenhq/radzen-blazor

Radzen.Blazor/RadzenDropDownDataGrid.razor.cs

master


      
              {
                  query = query.Where(grid.ColumnsCollection.Where(c => c.Filterable && IsColumnFilterPropertyTypeString(c))
                      .Select(c => new FilterDescriptor() { Property = c.GetFilterProperty(), FilterValue = searchText, FilterOperator = filterOperator }), 
                          LogicalFilterOperator.Or, FilterCaseSensitivity);
              }
          }
          else
          {
              if (AllowFilteringByWord)
              {
                  string[] words = searchText.Split(' ');
          
                  foreach (string word in words)
                  {
                      query = query.Where(TextProperty, word, FilterOperator, FilterCaseSensitivity);
                  }
              }
              else
              {
                  query = query.Where(TextProperty, searchText, FilterOperator, FilterCaseSensitivity);
              }

enchev · June 9, 2025, 8:12am

I've pushed update with your suggestions!