Illegal memory access in System.Runtime.Extensions.Tests

[EgorBo]

A crash in System.Runtime.Extensions.Tests tests (runtime-coreclr libraries-jitstress2-jitstressregs pipeline)

Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1242419&view=ms.vss-test-web.build-test-results-tab&runId=34579324&resultId=216483&paneView=dotnet-dnceng.dnceng-build-release-tasks.helix-test-information-tab
Build error leg or test failing:

Error Message

Fill the error message using step by step known issues guidance.

{
  "ErrorMessage": ["System.Runtime.Extensions.Tests","Illegal memory access. Deref invalid pointer, overrunning buffer, stack overflow etc. Core dumped"],
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1242419
Error message validated: [System.Runtime.Extensions.Tests Illegal memory access. Deref invalid pointer, overrunning buffer, stack overflow etc. Core dumped]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 1/23/2026 8:06:26 PM UTC

Report

Build	Definition	Test	Pull Request
1264233	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1264143	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution	#123530
1264105	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution	#123526
1264154	dotnet/runtime	LibraryImportGenerator.Unit.Tests.WorkItemExecution	#123514
1263640	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution	#123512
1263524	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1262850	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution	#123480
1262715	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution	#123378
1262575	dotnet/runtime	System.Memory.Tests.WorkItemExecution
1262487	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution	#123474
1261771	dotnet/runtime	System.Runtime.Tests.WorkItemExecution
1260803	dotnet/runtime	System.Net.Quic.Functional.Tests.WorkItemExecution	#123313
1260701	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1259962	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1258958	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1258626	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1258153	dotnet/runtime	System.Text.RegularExpressions.Tests.WorkItemExecution	#122093
1257915	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1257698	dotnet/runtime	System.Threading.Tasks.Dataflow.Tests.WorkItemExecution	#122371
1257619	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1257332	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1257166	dotnet/runtime	System.Text.Json.SourceGeneration.Roslyn3.11.Tests.WorkItemExecution	#123307
1257136	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1257011	dotnet/runtime	System.IO.FileSystem.Manual.Tests.WorkItemExecution	#123307
1256823	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1256393	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1255615	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1254946	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1254505	dotnet/runtime	LibraryImportGenerator.Unit.Tests.WorkItemExecution	#123218
1254178	dotnet/runtime	System.Private.Xml.Tests.WorkItemExecution
1253661	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1253422	dotnet/runtime	System.Text.Json.SourceGeneration.Roslyn4.4.Tests.WorkItemExecution	#123185
1252793	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1252082	dotnet/runtime	System.Net.Security.Unit.Tests.WorkItemExecution
1249191	dotnet/runtime	Microsoft.Extensions.Logging.Console.Tests.WorkItemExecution	#123015
1247931	dotnet/runtime	Microsoft.CSharp.Tests.WorkItemExecution	#123015
1246710	dotnet/runtime	System.Text.RegularExpressions.Tests.WorkItemExecution	#121412
1245124	dotnet/runtime	System.Text.Json.Tests.WorkItemExecution	#122944
1244235	dotnet/runtime	System.IO.FileSystem.Tests.WorkItemExecution	#122704
1243999	dotnet/runtime	LibraryImportGenerator.Unit.Tests.WorkItemExecution	#106374
1243591	dotnet/runtime	System.Text.RegularExpressions.Tests.WorkItemExecution	#122900
1242419	dotnet/runtime	System.Runtime.Extensions.Tests.WorkItemExecution

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
6	26	42

Report

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
0	0	0

[dotnet-policy-service]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.

[jkotas]

I have updated the filter to include System.Runtime.Extensions.Tests so that this is not picking up every segfault in the CI.

[JulieLeeMSFT]

Not happening recently, so closing it.