addrTo_in_addr access invalid memory with old libnl (3.4.0)

[ppiao]

Describe the bug

thom311/libnl@8d40d9e

before this commit netlink socket may return address with zero size.

bool addrTo_in_addr(struct nl_addr* ra, struct in_addr& addr)
{
   if (ra)
   {
      if (::nl_addr_get_family(ra) == AF_INET)
      {
         void* ba = ::nl_addr_get_binary_addr(ra);
         if (ba)
         {
            addr = *reinterpret_cast<struct in_addr*>(ba); // access invalid memory
            return true;
         }
      }
   }
   return false;
}

Describe the system
beegfs: master
libnl: libnl-route 3.4.0-1 ubuntu0.1