From owner-freebsd-security Mon Mar 15 1:46:18 1999 Delivered-To: freebsd-security@freebsd.org Received: from alcanet.com.au (border.alcanet.com.au [203.62.196.10]) by hub.freebsd.org (Postfix) with ESMTP id DB2B514FA9 for ; Mon, 15 Mar 1999 01:46:01 -0800 (PST) (envelope-from peter.jeremy@auss2.alcatel.com.au) Received: by border.alcanet.com.au id <40331>; Mon, 15 Mar 1999 19:33:24 +1000 Date: Mon, 15 Mar 1999 19:45:37 +1000 From: Peter Jeremy Subject: Re: ACL's To: freebsd-security@FreeBSD.ORG Message-Id: <99Mar15.193324est.40331@border.alcanet.com.au> Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org James Wyatt wrote: >Anyone else remember the UseNet wag who said "Symlinks can turn your >filesystem tree into a bramblebush."? Rich Salz, perhaps? - Jy@ There's also `symbolic links: GOTO's for filesystems'. Unfortunately, I don't remember the attribution. patl@phoenix.volant.org wrote: > (It can >detect a lost race condition by opening the file, doing the unlink, >then checking the link count on the open fd before closing.) And if this check fails, what should it do? It can't replace the link. Robert Watson wrote: >The s/owned/writable by/ change suggested sounds reasonable also. I >update my request for broken features and/or security holes given this >change: > >link(thefile, newname) will succeed only if open(thefile, O_RDWR) would >have succeeded, and if open(newname, O_CREAT, 0) would have succeeded. This sounds much better than my suggestion to chmod the file. I can't think of any breakage offhand. Peer To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message