Lost root password or missing /bin/sh

Mike Geddes

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Oct 18, 2001, 4:13:24 PM10/18/01

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Does anyone know how to recover from a lost root password on QNX6? The
knowledgebase on the QNX website explains how for QNX2 and QNX4, but not
QNX2.

Actually my problem is caused by changing the default shell for root to
/bin/tsch instead of /bin/sh. I downloaded the tsch thinking it would work
with QNX6, but it doesn't. Now I can't log in. I know I'm an idiot for not
testing it first, but I was in a hurry.

Thanks

Xiaodan Tang

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Oct 18, 2001, 5:25:32 PM10/18/01

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How about "press space" during boot. It give you a "safe boot" which you
can restrict only use "base package".

-xtang

Mike Geddes

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Oct 18, 2001, 6:06:01 PM10/18/01

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Thanks, but booting into safe mode still prompts for a password. I tried
various boot options but none seem to work.

I tried booting from the CD and editing the passwd file in the /fs directory
which contains the hard drive. I was able to get to the hard drives
/etc/passwd file and change it back to the sh rather than the tcsh shell. I
thought this would have fixed the problem since it's the only file I
modified. On reboot I still couldn't log in. Changing permissions on passwd
didn't help. I tried again with the CD, and erased the shadow and passwd
files. I replaced passwd with opasswd and I still can't get in. It's like it
doesn't even look at passwd anymore.

My next choice is to reinstall. Argh.

"Xiaodan Tang" <xt...@qnx.com> wrote in message
news:9qnhcc$d69$1...@nntp.qnx.com...

Cowboy

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Oct 30, 2001, 1:32:34 PM10/30/01

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In article <9qnji3$2gm$1...@inn.qnx.com>, Mike Geddes wrote:
>Thanks, but booting into safe mode still prompts for a password. I tried
>various boot options but none seem to work.
>
>I tried booting from the CD and editing the passwd file in the /fs directory
>which contains the hard drive. I was able to get to the hard drives
>/etc/passwd file and change it back to the sh rather than the tcsh shell. I
>thought this would have fixed the problem since it's the only file I
>modified. On reboot I still couldn't log in. Changing permissions on passwd
>didn't help. I tried again with the CD, and erased the shadow and passwd
>files. I replaced passwd with opasswd and I still can't get in. It's like it
>doesn't even look at passwd anymore.
>
>My next choice is to reinstall. Argh.

Well, I finally got the news server working for me, so may be a tad late,
but ...

If you can edit passwd ( hopefully you kept backups ) then all you need
do is change the user and group ID of a legit user who already has an
account, to 0 which will cause that user to BE root.
Boot the system, and log in as that user.
Now run passwd in a terminal window.
The system will change root's password to your new entry.

I nearly always leave some back door account with a 200 character
password in this condition on systems that I suspect might get some
abuse by someone with a root password who really should not have it.
It's a deliberate security hole.

Don't touch shadow. That could render ALL passwords bad, and then you
ARE screwed !

--
Cowboy

A plucked goose doesn't lay golden eggs.