System.Text.RegularExpressions.Tests fail with CREATE_CHECK_STRING(bSmallObjectHeapPtr || bLargeObjectHeapPtr)

[jkotas]

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1132704
Build error leg or test failing: System.Text.RegularExpressions.Tests.WorkItemExecution
Pull request: #119132

Error Message

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

{
  "ErrorMessage": ["System.Text.RegularExpressions.Tests","!CREATE_CHECK_STRING(bSmallObjectHeapPtr || bLargeObjectHeapPtr)"],
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1132704
Error message validated: [System.Text.RegularExpressions.Tests !CREATE_CHECK_STRING(bSmallObjectHeapPtr || bLargeObjectHeapPtr)]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 8/27/2025 12:37:54 PM UTC

Report

Summary

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

[MihuBot]

I'm a bot. Here is a possible related and/or duplicate issue (I may be wrong):

• System.Collections.Test: Assert failure '!CREATE_CHECK_STRING(bSmallObjectHeapPtr || bLargeObjectHeapPtr)' #111922

[jkotas]

Analysis of the dump runfo get-helix-payload -j 4ee844af-5426-4fc1-8e0e-c9e9e8a27146 -w System.Text.RegularExpressions.Tests -o c:\helix_payload:

Stacktrace of the crash:

libcoreclr!Object::ValidateInner+0x5ff [/__w/1/s/src/coreclr/vm/object.cpp @ 562] 
libcoreclr!OBJECTREF::OBJECTREF+0x58 [/__w/1/s/src/coreclr/vm/object.cpp @ 1088] 
libcoreclr!MethodDescCallSite::Call_RetOBJECTREF+0x20 [/__w/1/s/src/coreclr/vm/callhelpers.h @ 449] 
libcoreclr!LCGMethodResolver::GetLocalSig+0x1bd [/__w/1/s/src/coreclr/vm/callhelpers.h @ 15732480] 
libcoreclr!CEEInfo::getMethodInfoWorker+0x21b [/__w/1/s/src/coreclr/vm/jitinterface.cpp @ 15732480] 
libcoreclr!CEECodeGenInfo::CEECodeGenInfo+0x10d [/__w/1/s/src/coreclr/vm/jitinterface.cpp @ 10747] 
libcoreclr!CEEJitInfo::CEEJitInfo+0x12 [/__w/1/s/src/coreclr/vm/jitinterface.h @ 816] 
libcoreclr!UnsafeJitFunction+0x440 [/__w/1/s/src/coreclr/inc/volatile.h @ 13395] 

The object reference is valid. GC heap is not corrupted. The object was allocated very recently.

I think that the most likely explanation of the assertion failure is a race condition (memory model issue) in GCHeap::IsHeapPointer where it may return false for recently allocated objects from a different thread. @dotnet/gc Could you please take a look?

This is likely the same underlying problem as #117186

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