[BUG] Null pointer dereference vulnerability in parser.c

[shiyujunz]

I have found a potential null pointer dereference bug in parser.c and would like to report it to the maintainers. This vulnerability has the potential to cause unexpected application behavior, crashes. Can you please help me check it? Thank you for your effort and patience!

Below is the execution sequence of the program that may produce null pointer dereference bug .
First, in function parse_contrastive of file src/parser.c, yolo_layer is assigned null at line 379.
Second, if the conditional judgment on line 382 fails, yolo_layer will not be reassigned.
Finally, on line 383, yolo_layer is dereferenced, which can lead to a null pointer dereference vulnerability.

Thank you very much for reading and I look forward to hearing from you!