Re: 2.6.25.3: su gets stuck for root

Vegard Nossum
2008-05-13T06:47:40Z

Hi,

On Tue, May 13, 2008 at 8:17 AM, Harald Dunkel
<harald.dunkel@t-online.de> wrote:
> Hi folks,
>
> I haven't seen it mentioned here (hopefully I wasn't too blind to see):
>
> If I run "su someuser" as root, then it gets stuck. No prompt. I cannot
> interrupt it with ^C or ^Z either. /var/log/auth.log says:

...

> So obviously 'stty' is to blame here (called from root's .bashrc, as
> it seems). But for 2.6.24.4 there is no such problem.
>
>
> Maybe you could spread some light here?

Can you try to run "strace su someuser" instead?

This should produce some screenfulls of information, but will also
pinpoint the location of the hang in userspace if it's an error
somewhere in the path of a system call. Strace will output to stderr,
so use 2>strace.txt to capture it to a file. If you do this as root,
you should not have to enter any passwords, so they won't be logged
either.

Vegard

--
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
-- E. W. Dijkstra, EWD1036