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Date: Sat, 3 Jul 2004 13:35:56 -0700
From: Andrew Morton <akpm@osdl.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-kernel@vger.kernel.org, olaf+list.linux-kernel@olafdietsche.de
Subject: Re: procfs permissions on 2.6.x
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Christoph Hellwig <hch@infradead.org> wrote:
>
> On Sat, Jul 03, 2004 at 10:22:42PM +0200, Herbert Poetzl wrote:
> > 
> > Hi Andrew!
> > 
> > stumbled over the following detail ...
> > 
> > usually when somebody tries to modify an inode,
> > notify_change() calls inode_change_ok() to verify
> > the user's permissions ... now it seems that
> > somewhere around 2.5.41, a patch similar to this
> > one was included into the mainline, and remained
> > almost unmodified ...
> > 
> > http://www.uwsg.iu.edu/hypermail/linux/kernel/0210.1/1002.html
> > 
> > this probably unintentionally circumvents the 
> > inode_change_ok() check, so that now any user
> > can modify inodes of the procfs. 
> > 
> > example:
> > 
> >   $ chmod a-rwx /proc/cmdline
> > 
> > the following patch hopefully fixes this, so
> > please consider for inclusion ...
> 
> Actually the patch you reference above looks extremly bogus and should just
> be reverted instead.

Why is it "extremely bogus"?  I assume Olaf had a reason for wanting chmod
on procfs files?