From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.4 4/8] nilfs2: fix NULL pointer in nilfs_##name##_attr_release Date: Mon, 13 Sep 2021 18:35:57 -0400 Message-ID: <20210913223601.436675-4-sashal@kernel.org> References: <20210913223601.436675-1-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=1631572567; bh=yQ7g6GfvH1HNzUZvrjOX86u3ECpY2U1AAPFj28OrN64=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cDgWorh3Z0i9+OkaKYAnHIF89IxlJ060Iv/arcBgCfH2Lzg/4ZkPueKIzG4NPiEP0 vZbwE1ws0jO9dPD4LXsKPHklRr2tTosO6agNrJv1P0E8FckDzreBLTAzN3KFHLGmyO O1ThdGzeW2S89e2bwSOdaTZ7F+sYx5fD92lqp1n0AFFVKjOTDn7suY1/faQf3LDffT abN4MZkSyR56O8nZsHrQwAuUhnySQexOWPme5H3HZALBVtRokXJRrrwSeSVIItrB0X g6DiNKNHt61yxfKShPP//hG6EbvkVuCbEK0NWWEsunIq/ms5HHO/6EvsldYm3hhtGm SHMs9cXkqcPpA== In-Reply-To: <20210913223601.436675-1-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 69a8f302170e..d7d6791c408e 100644 --- a/fs/nilfs2/sysfs.c +++ b/fs/nilfs2/sysfs.c @@ -73,11 +73,9 @@ 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