static int sigignore(int sig) {
    struct sigaction sa = { .sa_handler = SIG_IGN, .sa_flags = 0 };

    if (sigemptyset(&sa.sa_mask) == -1 || sigaction(sig, &sa, 0) == -1) {
        return -1;
    }
    return 0;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.