Add missing array bounds checks in visitArrayRMW and visitArrayCmpxchg#8351
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kripken merged 1 commit intoWebAssembly:mainfrom Feb 21, 2026
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…ayCmpxchg The interpreter's visitArrayRMW and visitArrayCmpxchg were accessing data->values[indexVal] without first checking if indexVal is within bounds. This could lead to out-of-bounds memory access when the index exceeds the array length. Add the same bounds check pattern used by visitArrayGet and visitArraySet: trap with "array oob" when indexVal >= data->values.size().
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Normally this would require a test, but the upstream spec tests should cover it when they are finished.
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Summary
The interpreter's
visitArrayRMWandvisitArrayCmpxchginwasm-interpreter.haccessdata->values[indexVal]without verifying thatindexValis within the array's bounds. This can lead to out-of-bounds memory access when the index exceeds the array length.This PR adds the same bounds check pattern already used by
visitArrayGetandvisitArraySet:The check is added in both
visitArrayRMWandvisitArrayCmpxchg, immediately after computingindexValand before accessingdata->values[indexVal].Test plan
binaryen-unittests).visitArrayGet(line 2318) andvisitArraySet(line 2333), so it is consistent with the rest of the codebase.