# CVE-2022-50567: fs: jfs: fix shift-out-of-bounds in dbAllocAG

> A shift-out-of-bounds error in the Linux kernel JFS filesystem allows local attackers to cause a system crash via a crafted filesystem image.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Oct 2025
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-50567, GHSA-f88f-286j-xf6g, UBUNTU-CVE-2022-50567

## What is CVE-2022-50567?

CVE-2022-50567 is a high-severity vulnerability in Linux, published on 22 Oct 2025. 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:

fs: jfs: fix shift-out-of-bounds in dbAllocAG

Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The
underlying bug is the missing check of bmp->db_agl2size. The field can
be greater than 64 and trigger the shift-out-of-bounds.

Fix this bug by adding a check of bmp->db_agl2size in dbMount since this
field is used in many following functions. The upper bound for this
field is L2MAXL2SIZE - L2MAXAG, thanks for the help of Dave Kleikamp.
Note that, for maintenance, I reorganized error handling code of dbMount.

## Which versions are affected by CVE-2022-50567?


## How do I fix CVE-2022-50567?

Apply the vendor's patch.

## Is CVE-2022-50567 being exploited?

There is no known exploitation of CVE-2022-50567 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50567 and fix it if it is affected.

What it is: CVE-2022-50567 is a high-severity vulnerability in Linux, published on 22 Oct 2025. 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-2022-50567 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-2022-50567/ (Markdown: https://insights.sbomify.com/CVE-2022-50567/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50567
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50567
- OSV: https://osv.dev/vulnerability/CVE-2022-50567

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50567/
Summaries are generated and may contain mistakes; the official description above is the record.