ocfs2: validate dr_fs_generation of dir index root blocks

ocfs2_validate_dx_root() does not verify dr_fs_generation against the
superblock generation, unlike the extent and xattr block validators which
check h_fs_generation and xb_fs_generation respectively.  The field is
documented as "Must match super block".

Without the check, a stale dir index root block left on the device from
a previously formatted filesystem at the same physical block number can
pass validation as long as its signature, dr_blkno and checksum match.
Its index entries and suballocator information would then be used in
the new filesystem context.

Reject dir index root blocks whose dr_fs_generation does not match the
mounted filesystem, like the extent and xattr block validators do.

Link: https://lore.kernel.org/20260905142144.2869105-1-joseph.qi@linux.alibaba.com
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>

0 files changed, 0 insertions, 0 deletions