# CVE-2023-54255: sh: dma: Fix DMA channel offset calculation

> A flaw in the Linux kernel SH DMA driver causes incorrect offset calculations, leading to kernel panics and denial of service on affected SuperH architectures.

- **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:** 30 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-54255, DEBIAN-CVE-2023-54255, GHSA-hvj9-4j33-rmxc, UBUNTU-CVE-2023-54255

## What is CVE-2023-54255?

CVE-2023-54255 is a denial of service vulnerability in Linux, published on 30 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:

sh: dma: Fix DMA channel offset calculation

Various SoCs of the SH3, SH4 and SH4A family, which use this driver,
feature a differing number of DMA channels, which can be distributed
between up to two DMAC modules. The existing implementation fails to
correctly accommodate for all those variations, resulting in wrong
channel offset calculations and leading to kernel panics.

Rewrite dma_base_addr() in order to properly calculate channel offsets
in a DMAC module. Fix dmaor_read_reg() and dmaor_write_reg(), so that
the correct DMAC module base is selected for the DMAOR register.

## Which versions are affected by CVE-2023-54255?


## How do I fix CVE-2023-54255?

Apply the vendor's patch.

## Is CVE-2023-54255 being exploited?

There is no known exploitation of CVE-2023-54255 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54255 and fix it if it is affected.

What it is: CVE-2023-54255 is a denial of service vulnerability in Linux, published on 30 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-2023-54255 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-2023-54255/ (Markdown: https://insights.sbomify.com/CVE-2023-54255/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54255
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54255
- OSV: https://osv.dev/vulnerability/CVE-2023-54255

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54255/
Summaries are generated and may contain mistakes; the official description above is the record.