# CVE-2026-98030: net: dsa: bcm_sf2: bound the CFP rule dump by the caller's buffer size

> A local user can cause a kernel crash by triggering a null pointer dereference in the Broadcom SF2 DSA driver via a crafted ethtool ioctl call.

- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/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:** 25 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-104169, BELL-CVE-2026-98030, DEBIAN-CVE-2026-98030, GHSA-hmh5-2wm8-hhp7, UBUNTU-CVE-2026-98030

## What is CVE-2026-98030?

CVE-2026-98030 is a high-severity vulnerability in Linux, published on 25 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:

net: dsa: bcm_sf2: bound the CFP rule dump by the caller's buffer size

bcm_sf2_cfp_rule_get_all() walks the whole cfp.unique bitmap into
rule_locs[] without consulting nfc->rule_cnt, which is how many entries
the caller had room for.  ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN
and the ioctl sizes the buffer from the rule_cnt userspace passes in, so
once an admin has installed CFP rules any user can ask for fewer slots
than there are rules and run off the end of the allocation.  A rule_cnt
of 0 leaves the buffer pointer NULL and the walk dereferences it.

## Which versions are affected by CVE-2026-98030?


## How do I fix CVE-2026-98030?

Apply the vendor's patch.

## Is CVE-2026-98030 being exploited?

There is no known exploitation of CVE-2026-98030 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98030 and fix it if it is affected.

What it is: CVE-2026-98030 is a high-severity vulnerability in Linux, published on 25 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-2026-98030 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-2026-98030/ (Markdown: https://insights.sbomify.com/CVE-2026-98030/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98030
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98030
- OSV: https://osv.dev/vulnerability/CVE-2026-98030

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98030/
Summaries are generated and may contain mistakes; the official description above is the record.