CVE-2026-90204 ocfs2: validate DIO orphan slot during inode read
A corrupted OCFS2 inode can trigger a use-after-free in the Linux kernel, potentially allowing attackers to cause a crash or execute arbitrary code.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-90204?
CVE-2026-90204 is a high-severity use after free vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate DIO orphan slot during inode read
[BUG] A corrupted append-DIO dinode (high byte at offset 0xa1 corrupted from 0 to 1) can carry an i_dio_orphaned_slot outside the mounted filesystem slot range and trigger a use-after-free error:
BUG: KASAN: slab-use-after-free in ocfs2_get_system_file_inode+0x780/0x820 fs/ocfs2/sysfile.c:102 Read of size 8 at addr ffff88800b767c00 by task kworker/u8:3/85 Call Trace: ... ocfs2_get_system_file_inode+0x780/0x820 fs/ocfs2/sysfile.c:102 ocfs2_wipe_inode+0x292/0xf70 fs/ocfs2/inode.c:840 ocfs2_delete_inode fs/ocfs2/inode.c:1155 [inline] ocfs2_evict_inode+0x6c9/0x1170 fs/ocfs2/inode.c:1295 evict+0x38e/0x8f0 fs/inode.c:810 iput_final fs/inode.c:1914 [inline] iput fs/inode.c:1966 [inline] iput+0x55b/0x8b0 fs/inode.c:1926 ocfs2_recover_orphans+0x610/0xe40 fs/ocfs2/journal.c:2374 ocfs2_complete_recovery+0x5af/0xd00 fs/ocfs2/journal.c:1373 ...
[CAUSE] ocfs2_del_inode_from_orphan() uses i_dio_orphaned_slot to index the slot-local system inode cache. The dinode validator does not check this active slot, so an out-of-range value produces an invalid cache entry pointer that is dereferenced as an inode pointer.
[FIX] Reject an active i_dio_orphaned_slot outside the slot range during dinode validation, before DIO orphan recovery can consume it.
Which versions are affected by CVE-2026-90204?
How do I fix CVE-2026-90204?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-90204 being exploited?
There is no known exploitation of CVE-2026-90204 in the wild and no public exploit code.
Sources
Also known as AZL-102377, BELL-CVE-2026-90204, DEBIAN-CVE-2026-90204, GHSA-9rxc-xvxj-ggxx, UBUNTU-CVE-2026-90204.