Re: what's next for the linux kernel?

From: Bas Westerbaan
Date: Wed Oct 05 2005 - 15:53:43 EST


You can delete a directory entry to a file if you have proper
permission to the directory.

You cannot read or write the file if the file doesn't give you permission to.

A hard link makes an additional directory entry to a certain file. You
delete the directory entry to the file, not the file.

And permissions are the same for all instances of the file.

My 2 cents.

On 10/5/05, Julian Blake Kongslie <jblake@xxxxxxxxxxxxxxx> wrote:
> On Wed, 05 Oct 2005 13:27:15 -0700
> Marc Perkel <marc@xxxxxxxxxx> wrote:
> > There would be different rights to eack link.
>
> Well, color me confused.
>
> You appear to be saying that the permission on a file differ depending
> on which link you are accessing it by. Furthermore, your stance seems to
> imply that linking to a file grants either write permission or ownership
> on the new link.
>
> So, under this permission model, I could link to /etc/passwd in my
> home directory, edit the link to change my UID to zero, then relogin to
> the system as an administrator.
>
> Not that I would need to, of course, because any user who owns/could
> write to a directory would be able to alter any file on the entire
> system. I know they're called "permission" models, but that seems
> *extremely* permissive...
>
> --
> -Julian Blake Kongslie
> <jblake@xxxxxxxxxxxxxxx>
>
>
>



--
Bas Westerbaan
http://blog.w-nz.com/
GPG Public Keys: http://w-nz.com/keys/bas.westerbaan.asc
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