# CVE-2026-72411: net: dsa: mxl862xx: fix use-after-free of DSA ports in crc_err_work

> A use-after-free vulnerability in the Linux kernel's mxl862xx DSA driver allows attackers to cause denial of service or execute code via race conditions during device removal.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/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:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-72411, GHSA-426f-jh2p-2383, UBUNTU-CVE-2026-72411

## What is CVE-2026-72411?

CVE-2026-72411 is a high-severity use after free vulnerability in Linux, published on 15 Aug 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: mxl862xx: fix use-after-free of DSA ports in crc_err_work

Upon an MDIO CRC error mxl862xx_crc_err_work_fn() walks the DSA ports
and closes the CPU port conduits:

	dsa_switch_for_each_cpu_port(dp, priv->ds)
		dev_close(dp->conduit);

mxl862xx_remove() unregisters the switch before cancelling this work:

	set_bit(MXL862XX_FLAG_WORK_STOPPED, &priv->flags);
	cancel_delayed_work_sync(&priv->stats_work);
	dsa_unregister_switch(ds);
	mxl862xx_host_shutdown(priv);

dsa_unregister_switch() frees the dsa_port objects. If a CRC error
schedules the work during teardown it can run after the ports have been
freed and dereference freed memory.

Guard the port walk with MXL862XX_FLAG_WORK_STOPPED, which is already set
before dsa_unregister_switch(). DSA tears the ports down under
rtnl_lock(), so checking the flag under rtnl_lock() means the work either
runs before teardown and sees valid ports, or runs afterwards, observes
the flag and skips the walk. This mirrors the host_flood_work handler,
which skips torn-down ports under rtnl_lock().

## Which versions are affected by CVE-2026-72411?


## How do I fix CVE-2026-72411?

Apply the vendor's patch.

## Is CVE-2026-72411 being exploited?

There is no known exploitation of CVE-2026-72411 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72411 and fix it if it is affected.

What it is: CVE-2026-72411 is a high-severity use after free vulnerability in Linux, published on 15 Aug 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-2026-72411 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-2026-72411/ (Markdown: https://insights.sbomify.com/CVE-2026-72411/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72411
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72411
- OSV: https://osv.dev/vulnerability/CVE-2026-72411

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72411/
Summaries are generated and may contain mistakes; the official description above is the record.