From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1767013AbXDEOl2 (ORCPT ); Thu, 5 Apr 2007 10:41:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1767015AbXDEOl2 (ORCPT ); Thu, 5 Apr 2007 10:41:28 -0400 Received: from py-out-1112.google.com ([64.233.166.177]:18954 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1767013AbXDEOl1 (ORCPT ); Thu, 5 Apr 2007 10:41:27 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:date:from:to:cc:subject:message-id:reply-to:mail-followup-to:references:mime-version:content-type:content-disposition:in-reply-to:user-agent; b=d6fr+eGS3uFJxA8jopabQs6gAyyN2HAoidnXwQ36kQGG64aW1v+gjK4ZYrw7fxz0URU2a5UK3r86ECxHek+gKeSFTC4gLbf3OS16J55LDt3nW0vu8tSXJq4/sqX0mCHDCeK1dcD/E3RDPS52ENP38+wMrhwPV9kadSp8G2pAXLg= Date: Thu, 5 Apr 2007 22:44:09 +0800 From: WANG Cong To: Cornelia Huck Cc: linux-kernel@vger.kernel.org, Andrew Morton , viro@zeniv.linux.org.uk Subject: Re: [-mm3 PATCH] (Retry) Check the return value of kobject_add and etc. Message-ID: <20070405144409.GA5294@localhost.localdomain> Reply-To: WANG Cong Mail-Followup-To: Cornelia Huck , linux-kernel@vger.kernel.org, Andrew Morton , viro@zeniv.linux.org.uk References: <2375c9f90704010032r119f4a1eqb24dd611d5ecd943@mail.gmail.com> <20070402130128.707c8c19@gondolin.boeblingen.de.ibm.com> <20070405045410.GA4692@localhost.localdomain> <20070405111142.4723035f@gondolin.boeblingen.de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070405111142.4723035f@gondolin.boeblingen.de.ibm.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 05, 2007 at 11:11:42AM +0200, Cornelia Huck wrote: >On Thu, 5 Apr 2007 12:54:11 +0800, >WANG Cong wrote: > >> --- linux-2.6.21-rc5-mm3/fs/partitions/check.c.orig 2007-03-30 21:35:45.000000000 +0800 >> +++ linux-2.6.21-rc5-mm3/fs/partitions/check.c 2007-04-02 21:29:02.000000000 +0800 >> @@ -385,10 +385,18 @@ void add_partition(struct gendisk *disk, >> p->kobj.parent = &disk->kobj; >> p->kobj.ktype = &ktype_part; >> kobject_init(&p->kobj); >> - kobject_add(&p->kobj); >> + if (kobject_add(&p->kobj)) { >> + kfree(p); >> + return; >> + } >> if (!disk->part_uevent_suppress) >> kobject_uevent(&p->kobj, KOBJ_ADD); >> - sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem"); >> + if (sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem")) { >> + kobject_uevent(&p->kobj, KOBJ_REMOVE); >> + kobject_del(&p->kobj); >> + kfree(p); > >You should use kobject_put instead of kfree, since someone could have >(theoretically) obtained a reference on the object after the >kobject_add. (Or just use kobject_unregister, if the delete uevent >isn't suppressed anyway.) > I can't understand that. The memory pointed by 'p' is obtained via kmalloc(), _not_ kobject_get. How can we use kobject_put instead? Thanks!