nilfs2: initialize unused bytes in segment summary blocks

stable inclusion
from stable-v5.10.179
commit 2c90ef37151f9143c1bd18d8f76563f817632dbd
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8C809

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2c90ef37151f9143c1bd18d8f76563f817632dbd

--------------------------------

commit ef832747 upstream.

Syzbot still reports uninit-value in nilfs_add_checksums_on_logs() for
KMSAN enabled kernels after applying commit 73970316 ("nilfs2:
initialize "struct nilfs_binfo_dat"->bi_pad field").

This is because the unused bytes at the end of each block in segment
summaries are not initialized.  So this fixes the issue by padding the
unused bytes with null bytes.

Link: https://lkml.kernel.org/r/20230417173513.12598-1-konishi.ryusuke@gmail.com


Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by:  <syzbot+048585f3f4227bb2b49b@syzkaller.appspotmail.com>
  Link: https://syzkaller.appspot.com/bug?extid=048585f3f4227bb2b49b


Cc: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>
(cherry picked from commit 026f6589)