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Date: Tue, 20 Nov 2001 12:37:45 -0500 (EST)
From: Alexander Viro <viro@math.psu.edu>
To: Mike Castle <dalgoda@ix.netcom.com>
cc: linux-kernel@vger.kernel.org
Subject: Re: x bit for dirs: misfeature?
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On Tue, 20 Nov 2001, Mike Castle wrote:

> find /path/to/dir -type d -print0 | xargs -0 chmod a+rx
> find /path/to/dir -type f -print0 | xargs -0 chmod a+r
> 
> That way, xargs bunches up the arguments into as many arguments as chmod
> can handle, and calls it fewer times.
> 
> The -print0 and -0 are GNU extensions to handle spaces in names.

That's even worse than original.  You've got a very wide race here -
think what happens if luser does

cd /path/to/dir/something/writable/to/luser
mkdir bar
mkdir baz
for i in `seq 1 500`; do
	mkdir bar/$i
	touch bar/$i/shadow
	ln -sf /etc baz/$i
done

before you start, then waits for first chmod a+r and does

mv bar quux; mv baz bar

leaving you with very interesting results.  It's much wider window than
in the original.

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