Possible stack overflow in setup_random

        int seed_len = 0;
        /* Enter a loop to fill in seed with random data from /dev/urandom.
         * This is done in a loop so that we can safely handle short reads
         * which can happen due to signal interruptions.
         */
        while (seed_len < sizeof(seed)) {
            /* Assert we either read something or we were interrupted due to a
             * signal (errno == EINTR) in which case we need to retry.
             */
            int rc = read(fd, &seed + seed_len, sizeof(seed) - seed_len);
            assert(rc > 0 || errno == EINTR);
            if (rc > 0) {
                seed_len += rc;
            }
        }