# CVE-2026-98204: Input: rmi_smbus - fix out-of-bounds read in rmi_smb_write_block()

> A local attacker can trigger an out-of-bounds read in the RMI SMBus driver, potentially leaking kernel memory or causing a system crash.

- **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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106233, BELL-CVE-2026-98204, DEBIAN-CVE-2026-98204, GHSA-qm76-89x6-cmqm, UBUNTU-CVE-2026-98204

## What is CVE-2026-98204?

CVE-2026-98204 is a memory corruption vulnerability in Linux, published on 6 Oct 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:

Input: rmi_smbus - fix out-of-bounds read in rmi_smb_write_block()

When chunking writes into SMBus blocks in rmi_smb_write_block(), the
loop calculates block_len using the original total length (len) instead
of the remaining length (cur_len).

If len is greater than 32 bytes (SMB_MAX_COUNT), block_len remains 32
for every iteration, even on the final partial chunk where fewer than 32
bytes remain. This causes smb_block_write() to read 32 bytes from the
advanced data buffer pointer, reading past the end of the input buffer.

Fix this by calculating block_len using cur_len and advancing the buffer
and address pointers by block_len.

## Which versions are affected by CVE-2026-98204?


## How do I fix CVE-2026-98204?

Apply the vendor's patch.

## Is CVE-2026-98204 being exploited?

There is no known exploitation of CVE-2026-98204 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98204 and fix it if it is affected.

What it is: CVE-2026-98204 is a memory corruption vulnerability in Linux, published on 6 Oct 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-2026-98204 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-2026-98204/ (Markdown: https://insights.sbomify.com/CVE-2026-98204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98204
- OSV: https://osv.dev/vulnerability/CVE-2026-98204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98204/
Summaries are generated and may contain mistakes; the official description above is the record.