# CVE-2026-93269: ext4: fix circular lock dependency in ext4_ext_migrate

> A local attacker can trigger a deadlock in the ext4 filesystem during migration, causing a system denial of service.

- **Severity:** Not scored
- **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:** Yes
- **Published:** 24 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93269, DEBIAN-CVE-2026-93269, GHSA-9p82-h2x3-6rrv, UBUNTU-CVE-2026-93269

## What is CVE-2026-93269?

CVE-2026-93269 is a vulnerability in Linux, published on 24 Sep 2026. 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:

ext4: fix circular lock dependency in ext4_ext_migrate

Move iput(tmp_inode) after ext4_writepages_up_write() to avoid a
circular lock dependency between s_writepages_rwsem and sb_internal
(freeze protection).

The deadlock scenario:

  CPU0 (EXT4_IOC_MIGRATE)        CPU1 (orphan cleanup during mount)
  ----                           ----
  ext4_ext_migrate()
    ext4_writepages_down_write()
      s_writepages_rwsem (write)
                                 ext4_evict_inode()
                                   sb_start_intwrite()   [sb_internal]
                                   ...
                                     ext4_writepages()
                                       s_writepages_rwsem (read) [BLOCKED]
    iput(tmp_inode)
      ext4_evict_inode()
        sb_start_intwrite()         [BLOCKED]

The tmp_inode is a temporary inode with nlink=0 created solely for
building the extent tree.  Its eviction does not require
s_writepages_rwsem protection, so deferring iput() until after
releasing the rwsem is safe.

## Which versions are affected by CVE-2026-93269?


## How do I fix CVE-2026-93269?

Apply the vendor's patch.

## Is CVE-2026-93269 being exploited?

There is no known exploitation of CVE-2026-93269 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93269 and fix it if it is affected.

What it is: CVE-2026-93269 is a vulnerability in Linux, published on 24 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-93269 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-2026-93269/ (Markdown: https://insights.sbomify.com/CVE-2026-93269/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93269
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93269
- OSV: https://osv.dev/vulnerability/CVE-2026-93269

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93269/
Summaries are generated and may contain mistakes; the official description above is the record.