CVE-2025-39842

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: prevent release journal inode after journal shutdown

Before calling ocfs2_delete_osb(), ocfs2_journal_shutdown() has already

been executed in ocfs2_dismount_volume(), so osb->journal must be NULL.

Therefore, the following calltrace will inevitably fail when it reaches

jbd2_journal_release_jbd_inode().

ocfs2_dismount_volume()->

ocfs2_delete_osb()->

ocfs2_free_slot_info()->

__ocfs2_free_slot_info()->

evict()->

ocfs2_evict_inode()->

ocfs2_clear_inode()->

jbd2_journal_release_jbd_inode(osb->journal->j_journal,

Adding osb->journal checks will prevent null-ptr-deref during the above

execution path.