Comment 17 for bug 87023

Sworddragon, I believe this code from plugins/sudoers/check.c in check_user() prevents the tty reuse problem:

    /* Stash the tty's ctime for tty ticket comparison. */
    if (def_tty_tickets && user_ttypath && stat(user_ttypath, &sb) == 0) {
        tty_info.dev = sb.st_dev;
        tty_info.ino = sb.st_ino;
        tty_info.rdev = sb.st_rdev;
        if (tty_is_devpts(user_ttypath))
            ctim_get(&sb, &tty_info.ctime);
    }

    if (build_timestamp(&timestampdir, &timestampfile) == -1) {
        rval = -1;
        goto done;
    }

    status = timestamp_status(timestampdir, timestampfile, user_name,
        TS_MAKE_DIRS);

    if (status != TS_CURRENT || ISSET(validated, FLAG_CHECK_USER)) {
        /* Bail out if we are non-interactive and a password is required */
        if (ISSET(mode, MODE_NONINTERACTIVE)) {
            warningx(_("sorry, a password is required to run %s"), getprogname());
            rval = -1;
            goto done;
        }

        /* XXX - should not lecture if askpass helper is being used. */
        lecture(status);

        /* Expand any escapes in the prompt. */
        prompt = expand_prompt(user_prompt ? user_prompt : def_passprompt,
            user_name, user_shost);

        rval = verify_user(auth_pw, prompt);
    }
    /* Only update timestamp if user was validated. */
    if (rval == TRUE && ISSET(validated, VALIDATE_OK) &&
        !ISSET(mode, MODE_IGNORE_TICKET) && status != TS_ERROR)
        update_timestamp(timestampdir, timestampfile);

Thanks