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From:   wu000273@umn.edu
To:     konishi.ryusuke@gmail.com
Cc:     linux-nilfs@vger.kernel.org, linux-kernel@vger.kernel.org,
        kjlu@umn.edu, wu000273@umn.edu
Subject: [PATCH V2] nilfs2: Fix reference count leak in nilfs_sysfs_create_device_group
Date:   Wed, 27 May 2020 18:04:42 -0500
Message-Id: <20200527230442.24228-1-wu000273@umn.edu>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Qiushi Wu <wu000273@umn.edu>

kobject_init_and_add() takes reference even when it fails.
In nilfs_sysfs_create_device_group(), the memory allocated by
kobject_init_and_add() is not freed when kobject_init_and_add()
fails. Fix this issue by calling kobject_put() to clean up the
kobject.

Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/<device> group")
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
---
 V2: using kobject_put() to handle kobject_init_and_add() instead of
 kobject_del().

 fs/nilfs2/sysfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index e60be7bb55b0..8416f915d118 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -999,8 +999,10 @@ int nilfs_sysfs_create_device_group(struct super_block *sb)
 	init_completion(&nilfs->ns_dev_kobj_unregister);
 	err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL,
 				    "%s", sb->s_id);
-	if (err)
+	if (err) {
+		kobject_put(&nilfs->ns_dev_kobj);
 		goto free_dev_subgroups;
+	}
 
 	err = nilfs_sysfs_create_mounted_snapshots_group(nilfs);
 	if (err)
-- 
2.17.1