[PATCH v2 1/2] ubifs: dbg_check_idx_size: Fix kmemleak if loading znode failed

[Zhihao Cheng]

If function dbg_check_idx_size() failed by loading znode in mounting
process, there are two problems:
  1. Allocated znodes won't be freed, which causes kmemleak in kernel:
     ubifs_mount
      dbg_check_idx_size
       dbg_walk_index
        c->zroot.znode = ubifs_load_znode
	child = ubifs_load_znode // failed
	// Loaded znodes won't be freed in error handling path.
  2. Global variable ubifs_clean_zn_cnt is not decreased, because
     ubifs_tnc_close() is not invoked in error handling path, which
     triggers a warning in ubifs_exit():
      WARNING: CPU: 1 PID: 1576 at fs/ubifs/super.c:2486 ubifs_exit
      Modules linked in: zstd ubifs(-) ubi nandsim
      CPU: 1 PID: 1576 Comm: rmmod Not tainted 6.7.0-rc6
      Call Trace:
	ubifs_exit+0xca/0xc70 [ubifs]
	__do_sys_delete_module+0x29a/0x4a0
	do_syscall_64+0x6f/0x140

Fix it by invoking destroy_journal() if dbg_check_idx_size() failed.

Fixes: 1e51764a3c2a ("UBIFS: add new flash file system")
Signed-off-by: Zhihao Cheng <chengzhihao1 at huawei.com>
---
 fs/ubifs/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 09e270d6ed02..eabb0f44ea3e 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1449,7 +1449,7 @@ static int mount_ubifs(struct ubifs_info *c)
 
 	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
 	if (err)
-		goto out_lpt;
+		goto out_journal;
 
 	err = ubifs_replay_journal(c);
 	if (err)
-- 
2.31.1