# CVE-2023-54104: mtd: rawnand: fsl_upm: Fix an off-by one test in fun_exec_op()

> An off-by-one error in the Linux kernel's FSL UPM NAND driver allows out-of-bounds memory access, potentially causing crashes or undefined behavior.

- **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:** 24 Dec 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-54104, DEBIAN-CVE-2023-54104, GHSA-39vf-5xqf-2xfv, UBUNTU-CVE-2023-54104

## What is CVE-2023-54104?

CVE-2023-54104 is a high-severity vulnerability in Linux, published on 24 Dec 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:

mtd: rawnand: fsl_upm: Fix an off-by one test in fun_exec_op()

'op-cs' is copied in 'fun->mchip_number' which is used to access the
'mchip_offsets' and the 'rnb_gpio' arrays.
These arrays have NAND_MAX_CHIPS elements, so the index must be below this
limit.

Fix the sanity check in order to avoid the NAND_MAX_CHIPS value. This
would lead to out-of-bound accesses.

## Which versions are affected by CVE-2023-54104?


## How do I fix CVE-2023-54104?

Apply the vendor's patch.

## Is CVE-2023-54104 being exploited?

There is no known exploitation of CVE-2023-54104 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54104 and fix it if it is affected.

What it is: CVE-2023-54104 is a high-severity vulnerability in Linux, published on 24 Dec 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-2023-54104 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-2023-54104/ (Markdown: https://insights.sbomify.com/CVE-2023-54104/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54104
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54104
- OSV: https://osv.dev/vulnerability/CVE-2023-54104

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54104/
Summaries are generated and may contain mistakes; the official description above is the record.