Re: Overflowing Scripts fail to work

From: Peter Kosinar (goober@ksp.sk)
Date: Mon Apr 24 2006 - 18:11:59 EDT


> ###Content of exp.py########################
> #! /bin/env python
>
> import os
> os.system("./test "+("A" * 524))
> ############################################

As the others have already pointed out, the program (most likely) DOES
crash you just don't see the fancy "Speicherzugriffsfehler" /
"Segmentation fault" message. The reason is simple -- that message is not
produced by the failing program itself; it's written by bash/zsh/whatever
nice shell you're using when it detects that the spawned child process
has died because of SIGSEGV (signal 11). If you increase the rlimit on
coresize, you'll get the core file for later analysis.

It might be a good idea to prefix the os.system() call with something like
"print"; the program should output "11" which corresponds to the SIGSEGV
mentioned before.

Peter

-- 
[Name] Peter Kosinar   [Quote] 2B | ~2B = exp(i*PI)   [ICQ] 134813278
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