# 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.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-102377, BELL-CVE-2026-90204, DEBIAN-CVE-2026-90204, GHSA-9rxc-xvxj-ggxx, UBUNTU-CVE-2026-90204

## 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.

## Is CVE-2026-90204 being exploited?

There is no known exploitation of CVE-2026-90204 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90204 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-90204 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-90204/ (Markdown: https://insights.sbomify.com/CVE-2026-90204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90204
- OSV: https://osv.dev/vulnerability/CVE-2026-90204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90204/
Summaries are generated and may contain mistakes; the official description above is the record.