# CVE-2026-80985: net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry

> A remote attacker can corrupt memory and delete or install arbitrary rkeys in the Linux kernel SMC module by sending oversized LLC messages.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-80985, DEBIAN-CVE-2026-80985, GHSA-439p-4phc-pprq, UBUNTU-CVE-2026-80985

## What is CVE-2026-80985?

CVE-2026-80985 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry

smc_llc_rmt_delete_rkey() and smc_llc_save_add_link_rkeys() read the part
of a v2 message that does not fit into the 44-byte union smc_llc_msg, and
both bound themselves by the size of the buffer it landed in, not by what
arrived. On a link with a shared v2 receive buffer a 44-byte
DELETE_RKEY_V2 declaring 255 rkeys reaches rkey[9..254] in whatever an
earlier message left in lgr->wr_rx_buf_v2, and passes each of them to
smc_rtoken_delete(). One of those 255 matched a registered rtoken and
deleted it. An ADD_LINK on such a link installs up to 255 rtokens from
the same bytes.

Copy the tail into the queue entry, so its length is the length of the
message that arrived, and declare the rkeys that fit inline as a member of
the union instead of reaching them through a cast. The same
DELETE_RKEY_V2 now processes the 9 rkeys it carries. The copy is limited
to the longest tail the two functions can read, so the peer does not pick
the size of the entry.

The bound the previous patch placed on links without a shared v2 receive
buffer is no longer needed.

## Which versions are affected by CVE-2026-80985?


## How do I fix CVE-2026-80985?

Apply the vendor's patch.

## Is CVE-2026-80985 being exploited?

There is no known exploitation of CVE-2026-80985 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80985 and fix it if it is affected.

What it is: CVE-2026-80985 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80985 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-2026-80985/ (Markdown: https://insights.sbomify.com/CVE-2026-80985/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80985
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80985
- OSV: https://osv.dev/vulnerability/CVE-2026-80985

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80985/
Summaries are generated and may contain mistakes; the official description above is the record.