# CVE-2026-90113: netdevsim: update queue NAPI association on queue reset

> A use-after-free in the Linux kernel netdevsim driver allows local attackers to cause a crash or read memory via Netlink queue dumps after a queue reset.

- **Severity:** Not scored
- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-90113, DEBIAN-CVE-2026-90113, GHSA-wx7j-g336-w48j, UBUNTU-CVE-2026-90113

## What is CVE-2026-90113?

CVE-2026-90113 is an use after free vulnerability in Linux, published on 17 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:

netdevsim: update queue NAPI association on queue reset

In netdevsim, receive queues (struct nsim_rq) embed their own struct
napi_struct. When queue reset is performed (e.g. via queue_reset
debugfs), nsim_queue_start() swaps in a newly allocated struct nsim_rq,
and nsim_queue_mem_free() later deletes and frees the old one.

However, nsim_queue_start() failed to update the queue-to-NAPI mapping
via netif_queue_set_napi(). As a result, dev->_rx[idx].napi continued to
point to the old NAPI struct. After the old queue was freed, a subsequent
queue dump via Netlink (NETDEV_CMD_QUEUE_GET) triggered a KASAN
slab-use-after-free read in nla_put_napi_id() when accessing
rxq->napi->napi_id.

Fix this by calling netif_queue_set_napi() in nsim_queue_start() to
associate the new NAPI with the RX queue, and clear the association
with netif_queue_set_napi(..., NULL) in nsim_del_napi() during teardown.

## Which versions are affected by CVE-2026-90113?


## How do I fix CVE-2026-90113?

Apply the vendor's patch.

## Is CVE-2026-90113 being exploited?

There is no known exploitation of CVE-2026-90113 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90113 and fix it if it is affected.

What it is: CVE-2026-90113 is an use after free vulnerability in Linux, published on 17 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-2026-90113 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-2026-90113/ (Markdown: https://insights.sbomify.com/CVE-2026-90113/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90113
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90113
- OSV: https://osv.dev/vulnerability/CVE-2026-90113

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90113/
Summaries are generated and may contain mistakes; the official description above is the record.