I have build an ipk from C file and was working good. But yesterday I downloaded latest openwrt and built the ipk from using same C file. But now the application not working and gives segmentation fault. If I remove free() function then it works but application memory increases every second and when memory full restart occurs.
But still if I build the application using my old openwrt its works good.
I you have the possibility, try to use valgrind. Your application either double free's or writes outside the boundaries of the allocated blocks.
There have been major toolchain updates in master over the last three/ four weeks, gcc-8 to gcc-10, to finally gcc-11, musl (the libc) and more, you need to update your build environment as well (in lock-step). These newer versions might also force you to do minor adjustments/ fixes to your source.