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Message-ID: <5a3ed5650512250210w3528a8ccsb4df2c3a23863c40@mail.gmail.com>
Date: Sun, 25 Dec 2005 13:10:16 +0300
From: regatta <regatta@gmail.com>
To: Arjan van de Ven <arjan@infradead.org>
Subject: Re: FS possible security exposure ?
Cc: linux-kernel@vger.kernel.org
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I'm using Vi in Solaris and Vim in Linux, do you think this is the
problem ? (because when I use "echo BLABAL >> FILE_I_DONT_OWN_IT"  it
will give me permission denied in Linux)

but if you think about it, how could the system allow the user to
modify a file that he don't own it and he don't have write privilege
on the file just because he has write in the parent directory ?

Maybe I'm wrong, but is this normal ? please let me know

BTW: is there any document, article or any page about this so I can
show it to my boss :)

Thanks


On 12/25/05, Arjan van de Ven <arjan@infradead.org> wrote:
>
> > (when you have hundred of users and hundred of NFS and thousand of
> > net groups you don't want a user to edit other file just because he
> > has write permission in the patent dir).
>
> if you have write permission in the directory you're allowed to
> 1) create new files
> 2) rename existing files
> 3) delete files
> 4) rename files over existing files (combo of 2 and 3 sort of)
>
> so an "edit" as you describe is
> * create a new file with the new (eg modified) content
> * rename the new file over the existing file
>
> that's how reliable editors operate (the rename-over-file is an atomic
> operation) to avoid any possibility of dataloss due to crashes etc.
>
> Since the 1-4 rules are pretty much there for all unixes...
> Maybe your solaris editor doesn't do editing in this way?
>
>
>
>


--
Best Regards,
--------------------
-*- If Linux doesn't have the solution, you have the wrong problem -*-
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