From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932253AbVKKIqA (ORCPT ); Fri, 11 Nov 2005 03:46:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932243AbVKKIqA (ORCPT ); Fri, 11 Nov 2005 03:46:00 -0500 Received: from smtp.osdl.org ([65.172.181.4]:10427 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S932253AbVKKIp6 (ORCPT ); Fri, 11 Nov 2005 03:45:58 -0500 Date: Fri, 11 Nov 2005 00:45:54 -0800 From: Chris Wright To: Avi Kivity Cc: linux-kernel Subject: Re: local denial-of-service with file leases Message-ID: <20051111084554.GZ7991@shell0.pdx.osdl.net> References: <43737CBE.2030005@argo.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <43737CBE.2030005@argo.co.il> User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Avi Kivity (avi@argo.co.il) wrote: > the following program will oom a the 2.6.14.1 kernel, running as an > ordinary user: I don't have a good mechanism for testing leases, but this should fix the leak. Mind testing? thanks, -chris -- When unlocking lease make sure to release fasync_struct. Signed-off-by: Chris Wright --- diff --git a/fs/locks.c b/fs/locks.c index a1e8b22..abba0f6 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1412,7 +1412,7 @@ int fcntl_setlease(unsigned int fd, stru struct file_lock fl, *flp = &fl; struct dentry *dentry = filp->f_dentry; struct inode *inode = dentry->d_inode; - int error; + int error, on = 1; if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE)) return -EACCES; @@ -1433,7 +1433,10 @@ int fcntl_setlease(unsigned int fd, stru if (error) goto out_unlock; - error = fasync_helper(fd, filp, 1, &flp->fl_fasync); + if (arg == F_UNLCK) + on = 0; + + error = fasync_helper(fd, filp, on, &flp->fl_fasync); if (error < 0) { /* remove lease just inserted by __setlease */ flp->fl_type = F_UNLCK | F_INPROGRESS;