Sudo 命令失败，带有错误信息 "conversation failed, auth could not identify password for [user]"

Issue

• sudo 会重复提示输入密码
• 始终输入了正确的密码
• root 登录和密码可以正常工作

secure:Nov  4 09:58:18   sudo: pam_unix(sudo:auth): authentication failure; logname=testuser uid=1266 euid=0 tty=/dev/pts/5 ruser=testuser rhost=  user=testuser
secure:Nov  4 09:58:27   sudo: pam_unix(sudo:auth): conversation failed
secure:Nov  4 09:58:27   sudo: pam_unix(sudo:auth): auth could not identify password for [testuser]