# CVE-2026-92494: ext4: fix buffer_head leak in ext4_init_orphan_info

> A local attacker can cause a memory leak in the Linux kernel ext4 filesystem, potentially leading to denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102540, BELL-CVE-2026-92494, DEBIAN-CVE-2026-92494, GHSA-72fx-6p3v-7c2x, UBUNTU-CVE-2026-92494

## What is CVE-2026-92494?

CVE-2026-92494 is a memory corruption vulnerability in Linux, published on 17 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 buffer_head leak in ext4_init_orphan_info

ext4_init_orphan_info() reads orphan file blocks with ext4_bread()
and stores the returned buffer_head in oi->of_binfo[i].ob_bh.

If ext4_bread() succeeds but the orphan block magic or checksum
validation fails, the function jumps to out_free. However, the old
out_free loop starts releasing buffers from i - 1, so the current
buffer_head at index i is skipped.

This leaks the buffer_head reference obtained by ext4_bread() on the
bad magic and bad checksum error paths.

Fix this by tracking the number of successfully read buffer_heads and
releasing exactly those buffer_heads on the error path.

## Which versions are affected by CVE-2026-92494?


## How do I fix CVE-2026-92494?

Apply the vendor's patch.

## Is CVE-2026-92494 being exploited?

There is no known exploitation of CVE-2026-92494 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-92494 and fix it if it is affected.

What it is: CVE-2026-92494 is a memory corruption vulnerability in Linux, published on 17 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-2026-92494 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-2026-92494/ (Markdown: https://insights.sbomify.com/CVE-2026-92494/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-92494
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-92494
- OSV: https://osv.dev/vulnerability/CVE-2026-92494

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-92494/
Summaries are generated and may contain mistakes; the official description above is the record.