# CVE-2026-97599: ieee802154: hwsim: serialize pib updates to fix double-free


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-104658, BELL-CVE-2026-97599, DEBIAN-CVE-2026-97599, GHSA-r8g8-vw6g-m8xh, UBUNTU-CVE-2026-97599

## What is CVE-2026-97599?

CVE-2026-97599 is a vulnerability in Linux, published on 25 Sep 2026. 

### Official description

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

ieee802154: hwsim: serialize pib updates to fix double-free

hwsim_update_pib() does an unserialized read-swap-free of phy->pib:

	pib_old = rtnl_dereference(phy->pib);
	...
	rcu_assign_pointer(phy->pib, pib);
	kfree_rcu(pib_old, rcu);

It assumes the RTNL is held, but ->set_channel is not always called
under it: the mac802154 scan worker changes channels via
drv_set_channel() without the RTNL. Such an update can race an
RTNL-held one on the same phy; both read the same pib_old and both
kfree_rcu() it, double-freeing the object. With SLUB percpu sheaves
batching kfree_rcu(), this surfaces as a KASAN invalid-free in
rcu_free_sheaf().

struct hwsim_phy has no lock for pib. Add one and make the swap atomic
with rcu_replace_pointer() under it, dropping the misleading
rtnl_dereference().

## Which versions are affected by CVE-2026-97599?


## How do I fix CVE-2026-97599?

Upgrade to a fixed version.

## Is CVE-2026-97599 being exploited?

There is no known exploitation of CVE-2026-97599 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97599 and fix it if it is affected.

What it is: CVE-2026-97599 is a vulnerability in Linux, published on 25 Sep 2026. 
Exploitation: There is no known exploitation of CVE-2026-97599 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-2026-97599/ (Markdown: https://insights.sbomify.com/CVE-2026-97599/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97599
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97599
- OSV: https://osv.dev/vulnerability/CVE-2026-97599

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97599/
Summaries are generated and may contain mistakes; the official description above is the record.