In the Linux kernel, the following vulnerability has been resolved: ocfs2: prevent release journal inode after journal shutdown Before calling ocfs2deleteosb(), ocfs2journalshutdown() has already been executed in ocfs2dismountvolume(), so osb->journal must be NULL. Therefore, the following calltrace will inevitably fail when it reaches jbd2journalreleasejbdinode(). ocfs2dismountvolume()-> ocfs2deleteosb()-> ocfs2freeslotinfo()-> _ocfs2freeslotinfo()-> evict()-> ocfs2evictinode()-> ocfs2clearinode()-> jbd2journalreleasejbdinode(osb->journal->jjournal, Adding osb->journal checks will prevent null-ptr-deref during the above execution path.