Journal too short will cause ocfs2_check_volume failed, and will set journal->j_sb_buffer to NULL in journal_fail_superblock before running journal shutdown. Reported-and-tested-by: syzbot+05b9b39d8bdfe1a0861f@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=05b9b39d8bdfe1a0861f Signed-off-by: Edward Adam Davis <eadavis@xxxxxx> --- fs/ocfs2/journal.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c index 530fba34f6d3..25821077b855 100644 --- a/fs/ocfs2/journal.c +++ b/fs/ocfs2/journal.c @@ -1077,9 +1077,11 @@ void ocfs2_journal_shutdown(struct ocfs2_super *osb) BUG_ON(atomic_read(&(osb->journal->j_num_trans)) != 0); if (ocfs2_mount_local(osb)) { - jbd2_journal_lock_updates(journal->j_journal); - status = jbd2_journal_flush(journal->j_journal, 0); - jbd2_journal_unlock_updates(journal->j_journal); + if (journal->j_journal->j_sb_buffer) { + jbd2_journal_lock_updates(journal->j_journal); + status = jbd2_journal_flush(journal->j_journal, 0); + jbd2_journal_unlock_updates(journal->j_journal); + } if (status < 0) mlog_errno(status); } -- 2.43.0
