void unlinkClient(client *c) {
    listNode *ln;

    /* If this is marked as current client unset it. */
    if (server.current_client == c) server.current_client = NULL;

    /* Certain operations must be done only if the client has an active socket.
     * If the client was already unlinked or if it's a "fake client" the
     * fd is already set to -1. */
    if (c->fd != -1) {
        /* Remove from the list of active clients. */
        ln = listSearchKey(server.clients,c);
        serverAssert(ln != NULL);
        listDelNode(server.clients,ln);

        /* Unregister async I/O handlers and close the socket. */
        aeDeleteFileEvent(server.el,c->fd,AE_READABLE);
        aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);
        close(c->fd);
        c->fd = -1;
    }

    /* Remove from the list of pending writes if needed. */
    if (c->flags & CLIENT_PENDING_WRITE) {
        ln = listSearchKey(server.clients_pending_write,c);
        serverAssert(ln != NULL);
        listDelNode(server.clients_pending_write,ln);
        c->flags &= ~CLIENT_PENDING_WRITE;
    }

    /* When client was just unblocked because of a blocking operation,
     * remove it from the list of unblocked clients. */
    if (c->flags & CLIENT_UNBLOCKED) {
        ln = listSearchKey(server.unblocked_clients,c);
        serverAssert(ln != NULL);
        listDelNode(server.unblocked_clients,ln);
        c->flags &= ~CLIENT_UNBLOCKED;
    }
}

This label identifies security gaps where expected security features are missing or only partially implemented, reducing protection against unauthorized access or manipulation.