Re: execve problem with back-shell

[Michael Smith <mjs@smithbowen.net>]

Thanks for the suggestions, folks! 

On Mon, 7 Mar 2011 12:56:58 +0200
Buchan Milne <bgmilne@staff.telkomsa.net> wrote:
 
> What are the permissions of /usr/local/bin/backshell.sh ?
 
~# ls -l /usr/local/bin/backshell.sh
-rwxr-xr-x 1 mike mike 95 2011-03-04 15:29 /usr/local/bin/backshell.sh

Problem is the same if I try to execute a system binary, e.g. /bin/echo. 

And --

On Mon, 7 Mar 2011 11:10:57 +0000
Andrew Findlay <andrew.findlay@skills-1st.co.uk> wrote:

> On Sun, Mar 06, 2011 at 06:52:21PM -0500, Michael Smith wrote:
  
> Slapd is running as the 'openldap' user. Does that user have a valid
> shell? (i.e. can you do 'su openldap' and get a usable prompt?)
> Without that, you probably cannot run shell scripts in most modern
> systems.
> 
> Try setting openldap's shell to /bin/bash in /etc/passwd
 
This sounded promising. I followed the advice above but alas, no 
improvement. 

More oddities: 

The problem still arises even if I don't use the -u and -g flags, i.e.
I run slapd as root. Also, as noted above, it also happens if I try 
to run a binary rather than a script. 

Is it possible that execve is objecting to some environment setting? 
I know bupkis about the internals of execve. 

I guess my next step is to change the execve call in fork.c -- or no, 
I see it's an execv call, so it picks up the actual environment. Guess 
I could try changing it to execve and providing some minimal anodyne 
environment. Unless somebody else has a better idea?  

-- 
--

Michael J. Smith
mjs@smithbowen.net