transform.cc: potential index overflow

[ghost]

Here, https://github.com/dmlc/tvm/blob/0858c5ad42faefeefb7c24942a6bcbf075c4c4d7/src/relay/op/tensor/transform.cc#L1454

for (size_t i = 0; i < x_shape.size(); i++) {
    CHECK(reporter->AssertEQ(cond_shape[i], x_shape[i]))
        << "Shape of condition " << condition->shape
        << " must be either equal to x or has dimension of 1.";
  }

If cond_shape.size()=1 , and x_shape.size() = 2, then AssertEQ(cond_shape[i], x_shape[i]) will cause segment fault (array index overflow).

[tqchen]

@YPBlib can you send a PR to add additional checks to guard against this case? I think there is a case when cond_shape.size() == 1 but x_shape.size is not. which we need to have special way of handling it

[cchung100m]

Hi @YPBlib , @tqchen ,

I'm interested in working on this if no one else has signed up. I would appreciate if you can share more detailed thought for the implementation of additional check.

Many thanks,