From dbast0s@yahoo.com.br Tue Nov 25 09:10:08 2008
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From: Daniel Chicayban Bastos <dbast0s@yahoo.com.br>
Newsgroups: comp.unix.questions
Subject: problem 7; exploiting rm's usage
Date: Mon, 24 Nov 2008 16:42:51 +0100 (CET)
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This problem comes from 

                   http://cr.yp.to/2004-494/1209.pdf

I have not solved problem 7 and I'm curious. Since rm does not follow
symbolic links, and the files have different sizes, I'm not sure how
this can happen. Feel free to solve it.

Problem 7. The system administrator, after learning that the /home disk
is full, finds and removes a 40-gigabyte file:

% find /home -ls | sort -n +6 | tail -1 | awk '{print $11}'
/home/joe/just-testing/rc

% ls -l /home/joe/just-testing/rc
-rw-r--r-- 1 joe joe 41162685334 Dec 9 10:00 /home/joe/just-testing/rc

% rm /home/joe/just-testing/rc

% ls -l /home/joe/just-testing/rc
ls: /home/joe/just-testing/rc: No such file or directory
%

The system administrator later discovers, to his surprise, that the
important 16000-byte system fi le /etc/rc has disappeared. What exactly
did joe do?