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Date: Mon, 14 Apr 2008 17:54:52 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Jan Kara <jack@suse.cz>
Cc: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>,
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       Meelis Roos <mroos@linux.ee>,
       Linux Kernel list <linux-kernel@vger.kernel.org>,
       linux-fsdevel@vger.kernel.org
Subject: Re: file offset corruption on 32-bit machines?
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>   Well, but imagine you have a file /proc/my_secret_file from which you
> are able to read from position A:a and B:b but not from position
> A:b. Concievably, checks for the file position could be bypassed because of
> this race... I know this is kind of dumb example but I can imagine someone

Unlikely as the ppos passed to the driver is a private copy and the user
could equally use pread/pwrite to specify that offset.