ONNX: Null Pointer Dereference in ScanInferenceFunction Due to Missing Required Attribute

Summary ONNX shape inference did not safely validate the required Scan numscaninputs attribute. Two malformed values could terminate or disrupt the process: 1. If the attribute was missing, ctx.getAttribute"numscaninputs" returned null and was dereferenced. 2. If the attribute was negative,...