Login incorrect; valid user, no password prompt
I recently released a linux machine using the Samba/Winbind combo from the grips of an active directory server - a product I absolutely detest for a myriad of reasons which I won’t go into here.
So… in my haste, I forgot to do something and ended up with the following symptoms on a tty login:
Debian GNU/Linux lenny/sid slard tty1
slard login:
So I try to login…
Debian GNU/Linux lenny/sid slard tty1
slard login: root
LOGIN INCORRECT
Eh? What gives?
Turns out I forgot to fix my pam configuration under /etc/pam.d/common-password.
The solution? Assuming it’s your PAM configuration, boot into single user mode* and make sure your PAM configuration isn’t borked. I merely switched back to the default config:
password required pam_unix.so nullok obscure min=4 max=8 md5
*Not sure how to boot into single user mode? If you’re using grub:
Debian automatically adds a line for each kernel installed via debs that includes the normal kernel boot as well as a single user. If you don’t have that for whatever reason, just do it manually. At the grub menu, select the kernel you want to boot into and choose ‘e’ to edit the config. On the ‘kernel’ line, simply add the token ’single’. Then press ‘b’ to boot. You’ll boot into single-user mode; run level 1.