From owner-freebsd-hackers Sun Nov 7 10:10: 7 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from green.myip.org (localhost [127.0.0.1]) by hub.freebsd.org (Postfix) with ESMTP id 7B56114E52 for ; Sun, 7 Nov 1999 10:05:49 -0800 (PST) (envelope-from green@FreeBSD.org) Received: from localhost ([127.0.0.1] ident=green) by green.myip.org with esmtp (Exim 3.02 #1) id 11kCrK-0000Dg-00; Sat, 06 Nov 1999 15:54:51 -0500 Date: Sat, 6 Nov 1999 15:54:50 -0500 (EST) From: Brian Fundakowski Feldman X-Sender: green@green.myip.org To: Warner Losh Cc: "Daniel C. Sobral" , David Malone , freebsd-hackers@FreeBSD.ORG Subject: Re: Procfs' pointers to files. In-Reply-To: <199911062006.NAA00573@harmony.village.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sat, 6 Nov 1999, Warner Losh wrote: > There are ways that the user can see the code to execute it, but not > read it normally. procfs breaches this inability to read the file. > Also, there are many related problems which make a proper fix for this > that is more complicated than removing /proc/xxx/file nearly > impossible. "Proper" here means "A fix which will prevent the > disclosure of a file to unauthorized people which would normally not > be able to read the file." > > I'm convinced that it would be hard to codify all the security checks > needed to access the file originally into a single number which would > allow people that could read the original file to read /proc/xxx/file > and disallow people who couldn't read the file to also be disallowed > from reading /proc/xxx/file. It sounds to me that what you really want are the semantics of a symbolic link and not the semantics of a hard link. Is it just me, or does it seem as if the pathname of the executable being stored as a virtual symlink in procfs as "file" would solve these security problems? -- Brian Fundakowski Feldman \ FreeBSD: The Power to Serve! / green@FreeBSD.org `------------------------------' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message