c
size_t size = NLMSG_ALIGN(sizeof(struct ifaddrmsg));
if (size > SIZE_MAX - nla_total_size(1) - nla_total_size(4))
    goto errout;
size += nla_total_size(1) + nla_total_size(4);
skb = nlmsg_new(size, GFP_KERNEL);
