diff options
| author | Julian Sun <sunjunchao2870@gmail.com> | 2024-09-02 06:08:44 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-10 01:15:53 +0300 |
| commit | 5784d9fcfd43bd853654bb80c87ef293b9e8e80a (patch) | |
| tree | 1f4dcf3a0ed0c3c0b0f7ccd9f569e6419f35560d /fs/ocfs2 | |
| parent | 052a45c1cb1b32f05dd63a295d65496d8b403283 (diff) | |
| download | linux-5784d9fcfd43bd853654bb80c87ef293b9e8e80a.tar.xz | |
ocfs2: fix null-ptr-deref when journal load failed.
During the mounting process, if journal_reset() fails because of too short
journal, then lead to jbd2_journal_load() fails with NULL j_sb_buffer.
Subsequently, ocfs2_journal_shutdown() calls
jbd2_journal_flush()->jbd2_cleanup_journal_tail()->
__jbd2_update_log_tail()->jbd2_journal_update_sb_log_tail()
->lock_buffer(journal->j_sb_buffer), resulting in a null-pointer
dereference error.
To resolve this issue, we should check the JBD2_LOADED flag to ensure the
journal was properly loaded. Additionally, use journal instead of
osb->journal directly to simplify the code.
Link: https://syzkaller.appspot.com/bug?extid=05b9b39d8bdfe1a0861f
Link: https://lkml.kernel.org/r/20240902030844.422725-1-sunjunchao2870@gmail.com
Fixes: f6f50e28f0cb ("jbd2: Fail to load a journal if it is too short")
Signed-off-by: Julian Sun <sunjunchao2870@gmail.com>
Reported-by: syzbot+05b9b39d8bdfe1a0861f@syzkaller.appspotmail.com
Suggested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2')
| -rw-r--r-- | fs/ocfs2/journal.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c index 530fba34f6d3..1bf188b6866a 100644 --- a/fs/ocfs2/journal.c +++ b/fs/ocfs2/journal.c @@ -1055,7 +1055,7 @@ void ocfs2_journal_shutdown(struct ocfs2_super *osb) if (!igrab(inode)) BUG(); - num_running_trans = atomic_read(&(osb->journal->j_num_trans)); + num_running_trans = atomic_read(&(journal->j_num_trans)); trace_ocfs2_journal_shutdown(num_running_trans); /* Do a commit_cache here. It will flush our journal, *and* @@ -1074,9 +1074,10 @@ void ocfs2_journal_shutdown(struct ocfs2_super *osb) osb->commit_task = NULL; } - BUG_ON(atomic_read(&(osb->journal->j_num_trans)) != 0); + BUG_ON(atomic_read(&(journal->j_num_trans)) != 0); - if (ocfs2_mount_local(osb)) { + if (ocfs2_mount_local(osb) && + (journal->j_journal->j_flags & JBD2_LOADED)) { jbd2_journal_lock_updates(journal->j_journal); status = jbd2_journal_flush(journal->j_journal, 0); jbd2_journal_unlock_updates(journal->j_journal); |