Fixed stack overflow in pico_dns_decompress_name #473
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Hi,
I fixed the stack overflow in the function pico_dns_decompress_name.
In this function we had a buffer with a size of 256 bytes which is being filled inside a while loop.
The problem is that the break condition of this loop stops the loop only when reaching to a null terminator byte. An attacker can cause a stack overflow and possibly run an arbitrary code by sending a specially crafted packet.
Also, the functions pico_mdns_handle_data_as_answers_generic and pico_mdns_handle_single_question would have crashed if pico_dns_decompress_name returns NULL instead of an allocated buffer so I added a fix to them too.