Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750806AbWCVP4a (ORCPT ); Wed, 22 Mar 2006 10:56:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750835AbWCVP4a (ORCPT ); Wed, 22 Mar 2006 10:56:30 -0500 Received: from pat.uio.no ([129.240.130.16]:9703 "EHLO pat.uio.no") by vger.kernel.org with ESMTP id S1750806AbWCVP43 (ORCPT ); Wed, 22 Mar 2006 10:56:29 -0500 Subject: Re: DoS with POSIX file locks? From: Trond Myklebust To: Miklos Szeredi Cc: chrisw@sous-sol.org, matthew@wil.cx, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: <20060320121107.GE8980@parisc-linux.org> <20060320123950.GF8980@parisc-linux.org> <20060320153202.GH8980@parisc-linux.org> <1142878975.7991.13.camel@lade.trondhjem.org> <1142962083.7987.37.camel@lade.trondhjem.org> <20060321191605.GB15997@sorel.sous-sol.org> <1143025967.12871.9.camel@lade.trondhjem.org> Content-Type: text/plain Date: Wed, 22 Mar 2006 10:56:16 -0500 Message-Id: <1143042976.12871.34.camel@lade.trondhjem.org> Mime-Version: 1.0 X-Mailer: Evolution 2.4.1 Content-Transfer-Encoding: 7bit X-UiO-Spam-info: not spam, SpamAssassin (score=-3.333, required 12, autolearn=disabled, AWL 1.67, UIO_MAIL_IS_INTERNAL -5.00) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1124 Lines: 29 On Wed, 2006-03-22 at 13:16 +0100, Miklos Szeredi wrote: > > > > i concur with Trond, there's no sane way to get rid of it w/out > > > > formalizing CLONE_FILES and locks on exec > > > > > > Probably there is. It would involve allocating a separate > > > lock-owner-ID stored in files_struct but separate from it. But it's > > > more complicated than simply not propagating locks on exec in the > > > CLONE_FILES case. > > > > That doesn't solve the fundamental problem. > > > > You would still have to be able to tell a remote server that some locks > > which previously belonged to one owner are being reallocated to several > > owners. > > No changing of lock owner is involved, that's the whole point. You still don't get it. For NFS/CIFS/... the locks on the server _also_ have a lock owner. The local lockowner is completely and utterly irrelevant. Cheers, Trond - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/