ocfs2: validate l_tree_depth to avoid out-of-bounds access

[ Upstream commit a406aff8c05115119127c962cbbbbd202e1973ef ]

The l_tree_depth field is 16-bit (__le16), but the actual maximum depth is
limited to OCFS2_MAX_PATH_DEPTH.

Add a check to prevent out-of-bounds access if l_tree_depth has an invalid
value, which may occur when reading from a corrupted mounted disk [1].

Link: https://lkml.kernel.org/r/20250214084908.736528-1-kovalev@altlinux.org


Fixes: ccd979bd ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org>
Reported-by:  <syzbot+66c146268dc88f4341fd@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=66c146268dc88f4341fd

 [1]
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Kurt Hackel <kurt.hackel@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Vasiliy Kovalev <kovalev@altlinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>