Dropbear: exit status of remote shell not properly returned to client

Dr. H. Nikolaus Schaller hns at computer.org
Sat Aug 11 15:05:56 CEST 2007


Does anybody have the same experience?

The symptom is that I sometimes get the correct exit status and  
sometimes a 255 - for the same repeated command. i.e.:

$ ssh -l root 192.168.0.202 true ; echo $?
0
$ ssh -l root 192.168.0.202 true ; echo $?
255

Using ssh -vvv shows that the debug message:

debug1: client_input_channel_req: channel 0 rtype exit-status reply 0

is missing if ssh returns 255, i.e. dropbear does *not* provide the  
exit status and the client substitutes -1.

This appears to me to be the same bug as in the Changelog (although  
OpenMoko komes with version 0.49)

> 0.44 - Mon Jan 3 2005
>
> - Avoid a race in server shell-handling code which prevents the  
> exit-code
>   from being returned to the client in some circumstances.

Does anybody know a fix or is dropbear broken? Or is OpenSSH  
available for OpenMoko?

Nikolaus




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