# CVE-2026-80748: mmc: loongson2: Fix sg iteration in data reorder functions

> Incorrect scatterlist iteration in the Loongson2 MMC driver causes out-of-bounds memory access, potentially leading to system crashes or code execution.

- **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:** 3 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** BELL-CVE-2026-80748, DEBIAN-CVE-2026-80748, GHSA-rcvm-9rhr-j437, UBUNTU-CVE-2026-80748

## What is CVE-2026-80748?

CVE-2026-80748 is a high-severity memory corruption vulnerability in Linux, published on 3 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:

mmc: loongson2: Fix sg iteration in data reorder functions

In ls2k0500_mmc_reorder_cmd_data() and ls2k2000_mmc_reorder_cmd_data(),
the for_each_sg() macro already iterates over the scatterlist entries,
with 'sg' pointing to the current entry. However, the code incorrectly
uses '&sg[i]' and 'sg_dma_len(&sg[i])' inside the loop, which treats
'sg' as an array base and indexes it again, leading to access of
wrong sg entries (or out-of-bounds if the list is not an array).

## Which versions are affected by CVE-2026-80748?


## How do I fix CVE-2026-80748?

Apply the vendor's patch.

## Is CVE-2026-80748 being exploited?

There is no known exploitation of CVE-2026-80748 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80748 and fix it if it is affected.

What it is: CVE-2026-80748 is a high-severity memory corruption vulnerability in Linux, published on 3 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-2026-80748 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-2026-80748/ (Markdown: https://insights.sbomify.com/CVE-2026-80748/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80748
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80748
- OSV: https://osv.dev/vulnerability/CVE-2026-80748

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80748/
Summaries are generated and may contain mistakes; the official description above is the record.