Re: Proposal: restrict link(2)

Harald Koenig (koenig@tat.physik.uni-tuebingen.de)
Sat, 14 Dec 1996 01:24:38 +0100 (MET)


> Harald Koenig writes:
> > * clobber other user's disk quoatas, disk usage and disk space accounting etc.
>
> No.

[ nonsense example deleted ]

> You have only a cursory understanding of how hard links work.

bull shit! I guess you don't have an idea about disk quotas
and disk space accounting ???
usually you're not accounting disk space using "du"...

asume: /home/joe/BIGFILE is a big and $$$ file accessable to jim
owned by jim

now jim makes a hard link from this file to /home/jim/hidden/let_joe_still_pay

now assume that joe deletes /home/joe/BIGFILE in order to save disk spaces
accounted to his quota and probably $$$.

and now think again how ownes /home/jim/hidden/let_joe_still_pay,
how probably has to pay for it and who can't do anything against this..

got the message?

or other example about access restriction:
assume: jim and joe are in (some) same group(s)

/home/joe/project/world_shouldnt_read is a file that...
so directory "project" can only be accesed using group permission
(e.g. permission 770 or 750)

now jim (how is allowed to access project and thus project/world_shouldnt_read)
want's to make spy's life easier: he creates a hard link from the file above to

/home/jim/donnation_to_the_world/TOP_SECRET where donnation_to_the_world
ahs e.g. permissions 755. now world is able to access the data in the file
"world_shouldnt_read" which wasn't planed at all from joe
(using multiple differnet groups there are situations where you can't
remove world acces from this file; access control is done through directories...)

and what about the message of this case ?

BTW: I still saw now reasonable argument why we *need* the ability
that joe is allowed to create hard links to jim's files ?!

Harald

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