Re: backup method

[Han Boetes]

Richard Stallman wrote:
> But why avoid making backups for /tmp? Is there some specific
> reason why it is bad to make backups for /tmp? Or was the idea
> nothing more than "these files are unimportant anyway"?

Symlink attacks.

If you are going open /tmp/tmpfile, you will also create
/tmp/tmpfile~ as a backup. Now I can do two things:

1)
  touch /home/mine/foo
  chmod 666 /home/mine/foo
  ln -s /home/mine/foo /tmp/tmpfile~

And after the tmpfile creation of your file has been done I can
read the contents of the tempfile.

2)
  ln -s /home/you/.shellrc /tmp/tmpfile~

And making the backup will overwrite your .shellrc.



# Han