无法用普通帐号登录了，可以用root登录

yufeiluo

无法用普通帐号登录了，可以用root登录

cat  /var/log/auth.log

Feb  9 17:39:01 hwy CRON[3404]: pam_unix(cron:session): session opened for user root by (uid=0)
Feb  9 17:39:01 hwy CRON[3404]: pam_unix(cron:session): session closed for user root
Feb  9 17:40:01 hwy CRON[3459]: pam_unix(cron:session): session opened for user smmsp by (uid=0)
Feb  9 17:40:01 hwy CRON[3459]: pam_unix(cron:session): session closed for user smmsp
Feb  9 17:40:02 hwy polkitd(authority=local): Unregistered Authentication Agent for unix-session:12 (system bus name :1.116, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF- (disconnected from bus)
Feb  9 17:40:36 hwy CRON[641]: pam_unix(cron:session): session opened for user root by (uid=0)
Feb  9 17:40:36 hwy sshd[619]: Server listening on 0.0.0.0 port 22.
Feb  9 17:40:36 hwy sshd[619]: Server listening on :: port 22.
Feb  9 17:40:36 hwy CRON[641]: pam_unix(cron:session): session closed for user root
Feb  9 17:40:37 hwy systemd-logind[624]: New seat seat0.
Feb  9 17:40:37 hwy systemd-logind[624]: Watching system buttons on /dev/input/event4 (Power Button)
Feb  9 17:40:37 hwy systemd-logind[624]: Watching system buttons on /dev/input/event11 (Video Bus)
Feb  9 17:40:37 hwy systemd-logind[624]: Watching system buttons on /dev/input/event3 (Power Button)
Feb  9 17:40:47 hwy lightdm: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
Feb  9 17:40:47 hwy systemd-logind[624]: New session c1 of user lightdm.
Feb  9 17:40:48 hwy systemd: pam_unix(systemd-user:session): session opened for user lightdm by (uid=0)
Feb  9 17:40:51 hwy sshd[619]: Received SIGHUP; restarting.
Feb  9 17:40:51 hwy sshd[619]: Server listening on 0.0.0.0 port 22.
Feb  9 17:40:51 hwy sshd[619]: Server listening on :: port 22.
Feb  9 17:41:01 hwy lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm
Feb  9 17:41:01 hwy lightdm: pam_unix(lightdm:session): session opened for user lubantu by (uid=0)
Feb  9 17:41:01 hwy systemd-logind[624]: New session 2 of user lubantu.
Feb  9 17:41:01 hwy systemd: pam_unix(systemd-user:session): session opened for user lubantu by (uid=0)
Feb  9 17:41:01 hwy lightdm: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
Feb  9 17:41:01 hwy systemd-logind[624]: New session c2 of user lightdm.
Feb  9 17:41:04 hwy systemd-logind[624]: Removed session c1.
Feb  9 17:41:10 hwy lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm
Feb  9 17:41:10 hwy lightdm: pam_unix(lightdm:session): session opened for user root by (uid=0)
Feb  9 17:41:10 hwy systemd-logind[624]: New session 3 of user root.
Feb  9 17:41:10 hwy systemd: pam_unix(systemd-user:session): session opened for user root by (uid=0)
Feb  9 17:41:16 hwy polkitd(authority=local): Registered Authentication Agent for unix-session:3 (system bus name :1.24 [lxpolkit], object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-
Feb  9 17:43:01 hwy systemd-logind[624]: Removed session 2.
Feb  9 17:43:16 hwy lightdm: pam_unix(lightdm:session): session closed for user root
Feb  9 17:43:16 hwy polkitd(authority=local): Unregistered Authentication Agent for unix-session:3 (system bus name :1.24, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF- (disconnected from bus)
Feb  9 17:43:16 hwy lightdm: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
Feb  9 17:43:16 hwy systemd-logind[624]: New session c3 of user lightdm.
Feb  9 17:43:19 hwy systemd-logind[624]: Removed session c2.
Feb  9 17:43:26 hwy lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm
Feb  9 17:43:26 hwy lightdm: pam_unix(lightdm:session): session opened for user lubantu by (uid=0)
Feb  9 17:43:26 hwy systemd: pam_unix(systemd-user:session): session opened for user lubantu by (uid=0)
Feb  9 17:43:26 hwy systemd-logind[624]: New session 4 of user lubantu.
Feb  9 17:43:27 hwy lightdm: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
Feb  9 17:43:27 hwy systemd-logind[624]: New session c4 of user lightdm.
Feb  9 17:43:29 hwy systemd-logind[624]: Removed session c3.
Feb  9 17:43:32 hwy lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm
Feb  9 17:43:32 hwy lightdm: pam_unix(lightdm:session): session opened for user root by (uid=0)
Feb  9 17:43:32 hwy systemd-logind[624]: New session 5 of user root.
Feb  9 17:43:34 hwy polkitd(authority=local): Registered Authentication Agent for unix-session:5 (system bus name :1.48 [lxpolkit], object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-

root  和  lubuntu  是仅有的两个账户，查看日志信息也没有看到任何线索。