[PATCH 4.19 46/57] ocfs2: fix crash when initialize filecheck kobj fails

Greg Kroah-Hartman
2022-03-21T14:01:17Z

From: Joseph Qi <joseph.qi@linux.alibaba.com>

commit 7b0b1332cfdb94489836b67d088a779699f8e47e upstream.

Once s_root is set, genric_shutdown_super() will be called if
fill_super() fails. That means, we will call ocfs2_dismount_volume()
twice in such case, which can lead to kernel crash.

Fix this issue by initializing filecheck kobj before setting s_root.

Link: https://lkml.kernel.org/r/20220310081930.86305-1-joseph.qi@linux.alibaba.com
Fixes: 5f483c4abb50 ("ocfs2: add kobject for online file check")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ocfs2/super.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1150,17 +1150,6 @@ static int ocfs2_fill_super(struct super
goto read_super_error;
}

- root = d_make_root(inode);
- if (!root) {
- status = -ENOMEM;
- mlog_errno(status);
- goto read_super_error;
- }
-
- sb->s_root = root;
-
- ocfs2_complete_mount_recovery(osb);
-
osb->osb_dev_kset = kset_create_and_add(sb->s_id, NULL,
&ocfs2_kset->kobj);
if (!osb->osb_dev_kset) {
@@ -1178,6 +1167,17 @@ static int ocfs2_fill_super(struct super
goto read_super_error;
}

+ root = d_make_root(inode);
+ if (!root) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto read_super_error;
+ }
+
+ sb->s_root = root;
+
+ ocfs2_complete_mount_recovery(osb);
+
if (ocfs2_mount_local(osb))
snprintf(nodestr, sizeof(nodestr), "local");
else