[PATCH 5.19 127/158] ocfs2: fix freeing uninitialized resource on ocfs2_dlm_shutdown

[Greg Kroah-Hartman]

From: Heming Zhao <ocfs2-devel@xxxxxxxxxxxxxx>

commit 550842cc60987b269e31b222283ade3e1b6c7fc8 upstream.

After commit 0737e01de9c4 ("ocfs2: ocfs2_mount_volume does cleanup job
before return error"), any procedure after ocfs2_dlm_init() fails will
trigger crash when calling ocfs2_dlm_shutdown().

ie: On local mount mode, no dlm resource is initialized.  If
ocfs2_mount_volume() fails in ocfs2_find_slot(), error handling will call
ocfs2_dlm_shutdown(), then does dlm resource cleanup job, which will
trigger kernel crash.

This solution should bypass uninitialized resources in
ocfs2_dlm_shutdown().

Link: https://lkml.kernel.org/r/20220815085754.20417-1-heming.zhao@xxxxxxxx
Fixes: 0737e01de9c4 ("ocfs2: ocfs2_mount_volume does cleanup job before return error")
Signed-off-by: Heming Zhao <heming.zhao@xxxxxxxx>
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Changwei Ge <gechangwei@xxxxxxx>
Cc: Gang He <ghe@xxxxxxxx>
Cc: Jun Piao <piaojun@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/ocfs2/dlmglue.c |    8 +++++---
 fs/ocfs2/super.c   |    3 +--
 2 files changed, 6 insertions(+), 5 deletions(-)

--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -3403,10 +3403,12 @@ void ocfs2_dlm_shutdown(struct ocfs2_sup
 	ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
 	ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres);
 
-	ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
-	osb->cconn = NULL;
+	if (osb->cconn) {
+		ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
+		osb->cconn = NULL;
 
-	ocfs2_dlm_shutdown_debug(osb);
+		ocfs2_dlm_shutdown_debug(osb);
+	}
 }
 
 static int ocfs2_drop_lock(struct ocfs2_super *osb,
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1914,8 +1914,7 @@ static void ocfs2_dismount_volume(struct
 	    !ocfs2_is_hard_readonly(osb))
 		hangup_needed = 1;
 
-	if (osb->cconn)
-		ocfs2_dlm_shutdown(osb, hangup_needed);
+	ocfs2_dlm_shutdown(osb, hangup_needed);
 
 	ocfs2_blockcheck_stats_debugfs_remove(&osb->osb_ecc_stats);
 	debugfs_remove_recursive(osb->osb_debug_root);