# CVE-2026-72160: ocfs2: reject dinodes with non-canonical i_mode type

> Attackers can trigger memory corruption or crashes by mounting a crafted OCFS2 filesystem with invalid inode mode bits, requiring kernel patches.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72160, DEBIAN-CVE-2026-72160, GHSA-42g7-hf2f-vfr8, UBUNTU-CVE-2026-72160

## What is CVE-2026-72160?

CVE-2026-72160 is a high-severity memory corruption vulnerability in Linux, published on 15 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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

ocfs2: reject dinodes with non-canonical i_mode type

Patch series "ocfs2: harden inode validators against forged metadata", v2.

This series adds three structural checks to OCFS2 dinode validation so
malformed on-disk fields are rejected before ocfs2_populate_inode() copies
them into the in-core inode.

The checks cover:

  - i_mode values whose type bits do not name a canonical POSIX file
    type;
  - non-device dinodes whose id1.dev1.i_rdev field is non-zero; and
  - non-inline dinodes that claim non-zero i_size while i_clusters is
    zero, covering directories unconditionally and regular files on
    non-sparse volumes.

The normal read path reports these through ocfs2_error(), matching the
existing suballoc-slot, inline-data, chain-list, and refcount checks.  The
online filecheck path uses the same structural predicates but keeps its
own reporting contract, returning OCFS2_FILECHECK_ERR_INVALIDINO instead
of calling ocfs2_error().

This patch (of 3):

ocfs2_validate_inode_block() currently accepts any non-zero i_mode value. 
ocfs2_populate_inode() then copies that mode verbatim into inode->i_mode
and dispatches on i_mode & S_IFMT to the file/dir/symlink/special_file
iops; an unrecognised type falls through to ocfs2_special_file_iops and
init_special_inode().

Reject dinodes whose type bits do not name one of the seven canonical
POSIX file types.  Use fs_umode_to_ftype(), the same generic file-type
conversion helper OCFS2 already uses for directory entries, so the
accepted inode type set matches the kernel file-type vocabulary instead of
open-coding a local switch.

Apply the same structural check to the online filecheck read path. 
filecheck keeps its own error namespace, so it reports malformed i_mode
through the filecheck logger and OCFS2_FILECHECK_ERR_INVALIDINO instead of
calling ocfs2_error(), but it must not allow a malformed dinode to proceed
into ocfs2_populate_inode().

## Which versions are affected by CVE-2026-72160?


## How do I fix CVE-2026-72160?

Apply the vendor's patch.

## Is CVE-2026-72160 being exploited?

There is no known exploitation of CVE-2026-72160 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72160 and fix it if it is affected.

What it is: CVE-2026-72160 is a high-severity memory corruption vulnerability in Linux, published on 15 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-72160 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-2026-72160/ (Markdown: https://insights.sbomify.com/CVE-2026-72160/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72160
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72160
- OSV: https://osv.dev/vulnerability/CVE-2026-72160

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72160/
Summaries are generated and may contain mistakes; the official description above is the record.