Fix stack buffer overflow in get_view_as_real_copy_out_target_size (#15718)

Summary: Check that self.dim() is smaller than kTensorDimensionLimit,
otherwise we may write past the end of the out tensor.

Differential Revision: D86356264

Co-authored-by: lucylq <[email protected]>

Author: pytorchbot

kernels/portable/cpu/op_view_as_real_copy.cpp

@@ -41,6 +41,14 @@ Tensor& view_as_real_copy_out(
 
   // Get the output shape
   Tensor::SizesType expected_output_size[kTensorDimensionLimit];
+  ET_KERNEL_CHECK_MSG(
+      ctx,
+      static_cast<size_t>(self.dim()) < kTensorDimensionLimit,
+      InvalidArgument,
+      out,
+      "Output size buffer is too small. Expected at least %zu, got %zu",
+      self.dim() + 1,
+      kTensorDimensionLimit);
   get_view_as_real_copy_out_target_size(self, expected_output_size);
 
   // Resize for dynamic shape