# CVE-2024-42108: net: rswitch: Avoid use-after-free in rswitch_poll()

> A use-after-free in the rswitch network driver allows attackers to cause a system crash or potentially execute code via simple network packets.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jul 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-42108, DEBIAN-CVE-2024-42108, GHSA-g3v7-q58w-w9qx, UBUNTU-CVE-2024-42108

## What is CVE-2024-42108?

CVE-2024-42108 is a critical use after free vulnerability in Linux kernel, published on 30 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

net: rswitch: Avoid use-after-free in rswitch_poll()

The use-after-free is actually in rswitch_tx_free(), which is inlined in
rswitch_poll(). Since `skb` and `gq->skbs[gq->dirty]` are in fact the
same pointer, the skb is first freed using dev_kfree_skb_any(), then the
value in skb->len is used to update the interface statistics.

Let's move around the instructions to use skb->len before the skb is
freed.

This bug is trivial to reproduce using KFENCE. It will trigger a splat
every few packets. A simple ARP request or ICMP echo request is enough.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-42108?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-42108?

Apply the vendor's patch.

## Is CVE-2024-42108 being exploited?

There is no known exploitation of CVE-2024-42108 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-42108 and fix it if it is affected.

What it is: CVE-2024-42108 is a critical use after free vulnerability in Linux kernel, published on 30 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-42108 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2024-42108/ (Markdown: https://insights.sbomify.com/CVE-2024-42108/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-42108
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-42108
- OSV: https://osv.dev/vulnerability/CVE-2024-42108

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-42108/
Summaries are generated and may contain mistakes; the official description above is the record.