From owner-freebsd-bugs@FreeBSD.ORG  Tue Apr 13 21:41:17 2004
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To: "David G. Lawrence" <dg@dglawrence.com>
In-Reply-To: Your message of "Tue, 13 Apr 2004 20:43:42 PDT."
             <20040414034342.GA2439@nexus.dglawrence.com> 
Date: Wed, 14 Apr 2004 00:41:23 -0400
From: "Mark W. Krentel" <krentel@dreamscape.com>
cc: freebsd-bugs@FreeBSD.org
Subject: Re: kern/64573: mmap with PROT_NONE, but still could be read 
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>   Why would anyone want to mmap a file with PROT_NONE?

The same reason you're allowed to create a file with mode 000.  The 
OS doesn't make value judgements about your program.  If you ask for
PROT_NONE, then you're supposed to get PROT_NONE.

The same bug happens mmap()-ing a file with PROT_WRITE, you still get
read access.  In this case, PROT_NONE was just the simplest way to
demonstrate the bug.

--Mark