Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262136AbUKDHVT (ORCPT ); Thu, 4 Nov 2004 02:21:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262116AbUKDHPO (ORCPT ); Thu, 4 Nov 2004 02:15:14 -0500 Received: from [211.58.254.17] ([211.58.254.17]:64674 "EHLO hemosu.com") by vger.kernel.org with ESMTP id S262125AbUKDHDj (ORCPT ); Thu, 4 Nov 2004 02:03:39 -0500 Date: Thu, 4 Nov 2004 16:03:37 +0900 From: Tejun Heo To: mochel@osdl.org, greg@kroah.com Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.10-rc1 3/5] driver-model: sysfs_release() dangling pointer reference fix Message-ID: <20041104070337.GD25567@home-tj.org> References: <20041104070134.GA25567@home-tj.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041104070134.GA25567@home-tj.org> User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1229 Lines: 34 df_03_sysfs_release_fix.patch Some attributes are allocated dynamically (e.g. module and device parameters) and are usually deallocated when the assoicated kobject is released. So, it's not safe to access attr after putting the kobject. Signed-off-by: Tejun Heo Index: linux-export/fs/sysfs/file.c =================================================================== --- linux-export.orig/fs/sysfs/file.c 2004-11-04 10:25:58.000000000 +0900 +++ linux-export/fs/sysfs/file.c 2004-11-04 11:04:14.000000000 +0900 @@ -330,11 +330,13 @@ static int sysfs_release(struct inode * { struct kobject * kobj = to_kobj(filp->f_dentry->d_parent); struct attribute * attr = to_attr(filp->f_dentry); + struct module * owner = attr->owner; struct sysfs_buffer * buffer = filp->private_data; if (kobj) kobject_put(kobj); - module_put(attr->owner); + /* After this point, attr should not be accessed. */ + module_put(owner); if (buffer) { if (buffer->page) - 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/