Root Cause:

    The issue occurs when a DNS response is a fragmented packet. 

    ATCP will reassembles the fragments into a new packet and frees the original packets after reassembly. 

    However, due to a problem in parameter passing, the code continues to use the old, already-freed packet, leading to a ATCP crash.
Solution:

    Because we just want to check whether the packet is dns response or not, we shouldn't change the original packet,

    so we use the copy of original packet to check, and also avoid incorrect memory address passing issue.

Use python script to send an dns response packet which is fragment, check there is no system reboot occurs.