From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 5.4 08/12] nilfs2: fix NULL pointer in nilfs_##name##_attr_release Date: Mon, 13 Sep 2021 18:35:00 -0400 Message-ID: <20210913223504.436087-8-sashal@kernel.org> References: <20210913223504.436087-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631572516; bh=cTg0XQYisPWumgunZBEDqjWz7SV7k3sH8/WB6KzyuQU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=blpkHv+d6OVtCmZBCEj7eVURnhzcERDyYQet10UFiCDBU//UuJlmMOdaxHUHpef/s fUU6xtymLR11e3HVynRH3aObJYZwlznqpTe202Dkqo0myxeSBh6baU0LEVLn+xK1RY CMNOwnpN6707HLl1S3pt52ggu025RGBM/jgMtYGLdh2Pu0av6lGVHeuRjsWEsc5Hu/ jIU3Dz6bvLgzUxmZAE2G8EgtMwg3IQOILQ9vsE/d+RXR75cgl5v0G5LMRTeqnE5zi5 HvITtdtJEs1MxMDQfhbG8fdyU+CAOnyl0KhTO1Bkkk6AMMN1ZTG1vDwznLm/D53rfc 587crP+A1kzAA== In-Reply-To: <20210913223504.436087-1-sashal@kernel.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nanyong Sun , Ryusuke Konishi , Andrew Morton , Linus Torvalds , Sasha Levin , linux-nilfs@vger.kernel.org From: Nanyong Sun [ Upstream commit dbc6e7d44a514f231a64d9d5676e001b660b6448 ] 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 Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/nilfs2/sysfs.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c index cbfc132206e8..ca720d958315 100644 --- a/fs/nilfs2/sysfs.c +++ b/fs/nilfs2/sysfs.c @@ -64,11 +64,9 @@ static const struct sysfs_ops nilfs_##name##_attr_ops = { \ #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 = { \ -- 2.30.2