CVE-2025-39842 ocfs2: prevent release journal inode after journal shutdown
A null pointer dereference in the Linux kernel OCFS2 filesystem can cause a system crash during volume dismount.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-39842?
CVE-2025-39842 is a medium-severity vulnerability in Debian Debian Linux, published on 19 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2025-39842?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-39842?
Apply the vendor's patch.
Is CVE-2025-39842 being exploited?
There is no known exploitation of CVE-2025-39842 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-67529, BELL-CVE-2025-39842, DEBIAN-CVE-2025-39842, GHSA-24c6-4vcc-gq5v, ROOT-OS-DEBIAN-12-CVE-2025-39842, ROOT-OS-DEBIAN-13-CVE-2025-39842 and 2 more.