[ci-scan] Vector3Interop_r crash (SIGSEGV) under GCStress=0xC JitStress=2 (gcstress-extra pipeline)

[github-actions]

Reasoning

JIT/SIMD/Vector3Interop_r/Vector3Interop_r.cmd consistently crashes with a native SIGSEGV (App Exit Code 22) when run under DOTNET_GCStress=0xC DOTNET_JitStress=2 DOTNET_TieredCompilation=0 (the gcstress-extra pipeline configuration). The crash occurs in the PAL signal handler stack, indicating an unhandled memory access fault inside the JIT-compiled code while GC stress is active. This has been reproduced on linux-x64, osx-arm64, and linux-arm64 in at least two consecutive pipeline runs. It is not a test-infrastructure issue — Vector3Interop_r exercises Vector3 P/Invoke interop and Vector SIMD operations which are sensitive to the GC moving objects during JIT codegen stress.

Impact on platforms

• linux-x64 · pipeline 113 (gcstress-extra) · build 1406727 · work item JIT.SIMD.0.1 · Helix job 3565d1f5 · queue azurelinux.3.amd64.open.rt · exit code 22 · signal 11 (SIGSEGV)
• osx-arm64 · pipeline 113 · build 1406727 · work item JIT.SIMD.0.1 · Helix job 4bc8d02d · queue osx.15.arm64.open · exit code 22 · signal 11 (SIGSEGV)
• linux-arm64 · pipeline 113 · build 1406727 · work item JIT.SIMD.0.1 · Helix job 5bb4c8cb · exit code 22 · signal 11 (SIGSEGV)
• Confirmed recurring: same JIT.SIMD.0.1 failure in build 1406299 (2026-05-02)

Errors log

22:17:28.190 Running test: JIT/SIMD/Vector3Interop_r/Vector3Interop_r.cmd
[createdump] Gathering state for process ... dotnet
[createdump] Crashing thread f43a signal 11 (000b)
[createdump] Written 149319680 bytes to core file
App Exit Code: 22
END EXECUTION - FAILED
common_signal_handler(int, siginfo_t*, void*, int, ...) at src/coreclr/pal/src/exception/signal.cpp:1167:9
sigsegv_handler(int, siginfo_t*, void*) at src/coreclr/pal/src/exception/signal.cpp:762:1
```

Stress mode env:
```
DOTNET_TieredCompilation=0
DOTNET_GCStress=0xC
DOTNET_JitStress=2
DOTNET_DbgEnableMiniDump=1

First build it occurred

First seen in this scan window: build 1406299, finished 2026-05-02T22:30:29Z. Confirmed in subsequent build 1406727, finished 2026-05-04T01:11:48Z. Scanned window only — true origin may be earlier. Occurrences in window: 2+ builds, 3 platforms.

Recommended action

1. Triage: Run Vector3Interop_r locally with DOTNET_GCStress=0xC DOTNET_JitStress=2 DOTNET_TieredCompilation=0 to reproduce. Examine the crash dump for the faulting instruction and the managed/native call stack to determine whether the fault is in JIT-emitted code (bad code gen under stress), in the GC compaction path, or in the P/Invoke stub for Vector3.
2. JIT owners (@dotnet/area-infrastructure-coreclr-jit): Check whether the Vector3Interop test exercises a code path that is sensitive to the combination of GCStress=0xC (both 0x4 mark-phase and 0x8 compaction) and JitStress=2.
3. GC owners (@dotnet/area-gc): Verify whether the crash is triggered by a moving GC during a P/Invoke that holds a reference to a Vector3 value on the stack.
4. Short-term muting: If the crash is confirmed to be environment-specific (stress-only), add [ActiveIssue("https://github.com/dotnet/runtime/issues/<this>", typeof(TestLibrary.PlatformDetection), nameof(TestLibrary.PlatformDetection.IsStressTest))] to the Vector3Interop_r test.
5. Files to investigate: src/tests/JIT/SIMD/Vector3Interop/Vector3Interop.cs, src/coreclr/jit/lsra*.cpp (SIMD register allocation), src/coreclr/gc/gc.cpp (compaction + interop).

Note

🔒 Integrity filter blocked 4 items

The following items were blocked because they don't meet the GitHub integrity level.

• #125371 search_issues: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".
• #125825 search_issues: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".
• #55803 search_issues: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".
• #127128 search_issues: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".

To allow these resources, lower min-integrity in your GitHub frontmatter:

tools:
  github:
    min-integrity: approved  # merged | approved | unapproved | none

Generated by CI Outer-Loop Failure Scanner · ● 19.3M · ◷

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[kg]

Failed in (1):

• runtime-coreclr gcstress-extra 20260503.1

Console Log: Console Log

Source: runtime-coreclr gcstress-extra / coreclr linux arm64 Checked gcstress0xc_disabler2r_jitstress2 @ AzureLinux.3.Arm64.Open / JIT.SIMD.0.1

Generated by ci-pipeline-monitor/scripts/generate_report.py