From owner-cvs-all Sun Dec 10 22:36: 2 2000 From owner-cvs-all@FreeBSD.ORG Sun Dec 10 22:35:59 2000 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from ethel.williams.edu (ethel.williams.edu [137.165.33.22]) by hub.freebsd.org (Postfix) with ESMTP id D594037B400; Sun, 10 Dec 2000 22:35:58 -0800 (PST) Received: by ethel.williams.edu (Postfix, from userid 1001) id 47A1F37DD; Mon, 11 Dec 2000 01:35:52 -0500 (EST) Date: Mon, 11 Dec 2000 01:35:51 -0500 From: Chris Richards To: Robert Watson Cc: Garrett Wollman , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/etc crontab Message-ID: <20001211013551.A30301@ethel.williams.edu> References: <200012101856.NAA30441@khavrinen.lcs.mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii User-Agent: Mutt/1.0.1i In-Reply-To: ; from rwatson@FreeBSD.org on Sun, Dec 10, 2000 at 02:26:05PM -0500 Sender: crichard@ethel.williams.edu Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, Dec 10, 2000 at 02:26:05PM -0500, Robert Watson wrote: > > > As such, any random process running as any random user can acquire > > > the lock and stack up all your periodic scripts, > > > > If and only if they are allowed to open the file in the first place. > > This is correct. However, this does not apply to the periodic binary, > directories, or most base system files, unfortunately. Maybe we need a > /var/run/locks with appropriate turnstile files with appropriate modes > set. I don't understand what you mean to say here. What's to prevent the creation of a /var/run/periodic.lock, for example, with mode 600? Then periodic, running as root, will be able to aquire the advisory lock on this file, and ordinary users won't. The possibility of a DoS is thus eliminated. Am I missing something obvious? In the quoted material above, you seem to be suggesting that it is insecure to use most base system files as lock files. True -- but what would be the point in doing so? -chris To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message