From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 703E6C433FE for ; Wed, 8 Sep 2021 03:00:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 564E461131 for ; Wed, 8 Sep 2021 03:00:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234389AbhIHDBf (ORCPT ); Tue, 7 Sep 2021 23:01:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:59534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347404AbhIHDBU (ORCPT ); Tue, 7 Sep 2021 23:01:20 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CFAF161152; Wed, 8 Sep 2021 03:00:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1631070013; bh=4fSDOtrSzubOLYo0JDiLHe1pf/7qEeFWIzoGPoDQkp0=; h=Date:From:To:Subject:In-Reply-To:From; b=IRttpINJcG1WlbwTcnY8+9GRZi90oE2Pivt4pQZSk0q7M2IicJ2NW6D3X3gqzxxTQ 3LksFSp/1GYqhXdTHmLFBdJpdPUa42JSxAKeEF72L3Tex4Z8bstrHtsyHfNB3ycj9I pyxUwIryMZaXZEw1qMLQyxffyA5SRkiecnSW463E= Date: Tue, 07 Sep 2021 20:00:12 -0700 From: Andrew Morton To: akpm@linux-foundation.org, konishi.ryusuke@gmail.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, sunnanyong@huawei.com, torvalds@linux-foundation.org Subject: [patch 131/147] nilfs2: fix NULL pointer in nilfs_##name##_attr_release Message-ID: <20210908030012.V2Y-aQS5E%akpm@linux-foundation.org> In-Reply-To: <20210907195226.14b1d22a07c085b22968b933@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Nanyong Sun Subject: nilfs2: fix NULL pointer in nilfs_##name##_attr_release In nilfs_##name##_attr_release, kobj->parent should not be referenced because it is a NULL pointer. The release() method of kobject is always called in kobject_put(kobj), in the implementation of kobject_put(), the kobj->parent will be assigned as NULL before call the release() method. So just use kobj to get the subgroups, which is more efficient and can fix a NULL pointer reference problem. Link: https://lkml.kernel.org/r/20210629022556.3985106-3-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-3-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton --- fs/nilfs2/sysfs.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/fs/nilfs2/sysfs.c~nilfs2-fix-null-pointer-in-nilfs_name_attr_release +++ a/fs/nilfs2/sysfs.c @@ -51,11 +51,9 @@ static const struct sysfs_ops nilfs_##na #define NILFS_DEV_INT_GROUP_TYPE(name, parent_name) \ static void nilfs_##name##_attr_release(struct kobject *kobj) \ { \ - struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \ - struct the_nilfs *nilfs = container_of(kobj->parent, \ - struct the_nilfs, \ - ns_##parent_name##_kobj); \ - subgroups = nilfs->ns_##parent_name##_subgroups; \ + struct nilfs_sysfs_##parent_name##_subgroups *subgroups = container_of(kobj, \ + struct nilfs_sysfs_##parent_name##_subgroups, \ + sg_##name##_kobj); \ complete(&subgroups->sg_##name##_kobj_unregister); \ } \ static struct kobj_type nilfs_##name##_ktype = { \ _