Blazor server crashes when dotnetreference calls a c# function with a string as parameter with more than 32707 characters

[MarvinKlein1508]

Describe the bug

I am generating a CKEditor 5 with a custom library. The editor fires an JavaScript event which is calling a dotnetreference and forward the new content of the editor to the C# function. However this process results in a crash of my blazor server app, when the text exceeds the length of 32700 characters. The real length is 32707 because all content will be wrapped within a <p></p> tag.

To Reproduce

I created a short sample repo which can be found here: https://github.com/MarvinKlein1508/LargeText

Simple add another s to the textbox to trigger the crash.

Exceptions (if any)

I only get this error within the browsers console.
[2021-06-22T08:49:25.907Z] Error: Connection disconnected with error 'Error: Server returned an error on close: Connection closed with an error.'. blazor.server.js:1:5481
log https://localhost:5001/_framework/blazor.server.js:1
stopConnection https://localhost:5001/_framework/blazor.server.js:1
onclose https://localhost:5001/_framework/blazor.server.js:1
close https://localhost:5001/_framework/blazor.server.js:1
stop https://localhost:5001/_framework/blazor.server.js:1
stopInternal https://localhost:5001/_framework/blazor.server.js:1
s https://localhost:5001/_framework/blazor.server.js:1
s https://localhost:5001/_framework/blazor.server.js:1
a https://localhost:5001/_framework/blazor.server.js:1

Further technical details

• ASP.NET Core version: 5.0.7
  .NET SDK (gemäß "global.json"):
  Version: 6.0.100-preview.3.21202.5
  Commit: aee38a6dd4

Laufzeitumgebung:
OS Name: Windows
OS Version: 10.0.19043
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\6.0.100-preview.3.21202.5\

Host (useful for support):
Version: 6.0.0-preview.3.21201.4
Commit: 236cb21e3c

.NET SDKs installed:
3.1.400-preview-015203 [C:\Program Files\dotnet\sdk]
3.1.410 [C:\Program Files\dotnet\sdk]
5.0.100-rc.1.20452.10 [C:\Program Files\dotnet\sdk]
5.0.100 [C:\Program Files\dotnet\sdk]
5.0.103 [C:\Program Files\dotnet\sdk]
5.0.104 [C:\Program Files\dotnet\sdk]
5.0.201 [C:\Program Files\dotnet\sdk]
5.0.202 [C:\Program Files\dotnet\sdk]
5.0.204 [C:\Program Files\dotnet\sdk]
5.0.300-preview.21258.4 [C:\Program Files\dotnet\sdk]
5.0.301 [C:\Program Files\dotnet\sdk]
6.0.100-preview.3.21202.5 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.28 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.28 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.16 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.0-rc.1.20451.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.0-preview.3.21201.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.28 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.16 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.0-rc.1.20451.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.0-preview.3.21201.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.16 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.0-rc.1.20452.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.7 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.0-preview.3.21201.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
https://aka.ms/dotnet-download

[javiercn]

@MarvinKlein1508 thanks for contacting us.

This is expected, since you are hitting the SignalR message size limit. This limit is there for security reasons, otherwise someone could easily force large allocations on your server.

We are currently working on a feature for 6.0 that will allow you to "stream" payloads to the server that are larger than the SignalR message limit with full control over the total size of the data on the server.

[javiercn]

See #30289 for details