# CVE-2026-98359: RDMA/core: Reject unregistering netdevs in ib_get_eth_speed

> A missing state check in the Linux kernel RDMA core allows accessing unregistered network devices, potentially causing a null pointer dereference and system crash.

- **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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106395, BELL-CVE-2026-98359, DEBIAN-CVE-2026-98359, GHSA-fhcv-jhv5-h3gg, UBUNTU-CVE-2026-98359

## What is CVE-2026-98359?

CVE-2026-98359 is a high-severity 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:

RDMA/core: Reject unregistering netdevs in ib_get_eth_speed

ib_device_get_netdev() intentionally returns a referenced net_device even
when it is unregistering, so matching and cleanup callers can still find
the association. The reference keeps struct net_device allocated, but does
not guarantee that the device remains operational.

ib_get_eth_speed() uses the returned device operationally by invoking its
ethtool callback. Although that call is made under RTNL, the function does
not verify the registration state first. An asynchronous RDMA port query
can therefore call into a netdev after NETDEV_UNREGISTER and ndo_uninit
have completed.

Check for NETREG_REGISTERED while holding RTNL and return -ENODEV for a
device which is being unregistered. Keeping RTNL across the check and the
ethtool operation prevents unregister from starting between them.

Keep the speed fallback and warning under RTNL as well, so the warning can
safely read netdev->name. Drop the netdev reference before releasing RTNL
once all accesses to the device are complete.

## Which versions are affected by CVE-2026-98359?


## How do I fix CVE-2026-98359?

Apply the vendor's patch.

## Is CVE-2026-98359 being exploited?

There is no known exploitation of CVE-2026-98359 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98359 and fix it if it is affected.

What it is: CVE-2026-98359 is a high-severity 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-2026-98359 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-2026-98359/ (Markdown: https://insights.sbomify.com/CVE-2026-98359/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98359
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98359
- OSV: https://osv.dev/vulnerability/CVE-2026-98359

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98359/
Summaries are generated and may contain mistakes; the official description above is the record.