Centos 普通用户su到root用户提示错误

水深无声 2022-05-29 22:39 2045阅读 0赞

## 一、CentOS7 ##

普通用户执行su时，报如下错误：

[test@ecs-1453 ~]$ su -
    Password: 
    su: Authentication failure

解决方法：

如果root能够正常登陆，就先使用root用户登录系统，再执行操作

1、登陆root账户；  
2、执行sudo -i

[root@ecs-1453 ~]# sudo -i

3、执行chmod +s /bin/su

[root@ecs-1453 ~]# chmod +s /bin/su

4、验证

[test@ecs-1453 ~]$ su - root
    Password: 
    su: Authentication failure
    [test@ecs-1453 ~]$ su - root
    Password: 
    Last login: Tue Feb 27 18:44:34 CST 2018 on pts/0
    Last failed login: Tue Feb 27 18:45:42 CST 2018 on pts/1
    There was 1 failed login attempt since the last successful login.

![20180227190630663][]

## 二、centos6 ##

普通用户执行su时，报错如下：

[test@ecs-19cb ~]$ su - root
    Password: 
    su: incorrect password

解决方法：

如果root能够正常登陆，就先使用root用户登录系统，再执行操作

1、登陆root账户；  
2、查看/etc/pam.d/su配置文件，\#auth required pam\_wheel.so use\_uid 这句是否被启用，如果启用了，那么加入了wheel组的用户（usermod -g  wheel 用户id）才能su，否则就会提示密码错误。

[root@ecs-19cb ~]# vim /etc/pam.d/su

#%PAM-1.0
    auth            sufficient      pam_rootok.so
    # Uncomment the following line to implicitly trust users in the "wheel" group.
    #auth           sufficient      pam_wheel.so trust use_uid
    # Uncomment the following line to require a user to be in the "wheel" group.
    #auth            required       pam_wheel.so use_uid
    auth            include         system-auth
    account         sufficient      pam_succeed_if.so uid = 0 use_uid quiet
    account         include         system-auth
    password        include         system-auth
    session         include         system-auth
    session         optional        pam_xauth.so#auth            required       pam_wheel.so use_uid
    auth            include         system-auth
    account         sufficient      pam_succeed_if.so uid = 0 use_uid quiet
    account         include         system-auth
    password        include         system-auth
    session         include         system-auth
    session         optional        pam_xauth.so

3、查看文件权限，正确如下

[root@ecs-19cb ~]# ll -a /bin/su 
    -rwsr-xr-x. 1 root root 34904 May 11  2016 /bin/su
    [root@ecs-19cb ~]# ll -a /usr/bin/passwd 
    -rwsr-xr-x. 1 root root 30768 Nov 24  2015 /usr/bin/passwd

4、验证

[test@ecs-19cb ~]$ su - root
    Password: 
    su: incorrect password
    [test@ecs-19cb ~]$ su - root
    Password: 
    [root@ecs-19cb ~]#

![20180227202147748][]

[20180227190630663]: /images/20220530/db1f27ddcd0d45c09d4ff02b2574f215.png
[20180227202147748]: /images/20220530/8fdb17dfc0c24330af50f4977ecaa461.png