# CVE-2024-45016: netem: fix return value if duplicate enqueue fails

> A use-after-free vulnerability in the Linux kernel netem qdisc allows local attackers to potentially execute code or escalate privileges.

- **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:** 11 Sep 2024
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-49211, AZL-49239, BELL-CVE-2024-45016, DEBIAN-CVE-2024-45016, GHSA-q53p-qm4c-c2wj, SUSE-SU-2025:0414-1, UBUNTU-CVE-2024-45016, USN-7071-1, USN-7071-2

## What is CVE-2024-45016?

CVE-2024-45016 is a high-severity use after free vulnerability in Linux kernel, published on 11 Sep 2024. 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:

netem: fix return value if duplicate enqueue fails

There is a bug in netem_enqueue() introduced by
commit 5845f706388a ("net: netem: fix skb length BUG_ON in __skb_to_sgvec")
that can lead to a use-after-free.

This commit made netem_enqueue() always return NET_XMIT_SUCCESS
when a packet is duplicated, which can cause the parent qdisc's q.qlen
to be mistakenly incremented. When this happens qlen_notify() may be
skipped on the parent during destruction, leaving a dangling pointer
for some classful qdiscs like DRR.

There are two ways for the bug happen:

- If the duplicated packet is dropped by rootq->enqueue() and then
  the original packet is also dropped.
- If rootq->enqueue() sends the duplicated packet to a different qdisc
  and the original packet is dropped.

In both cases NET_XMIT_SUCCESS is returned even though no packets
are enqueued at the netem qdisc.

The fix is to defer the enqueue of the duplicate packet until after
the original packet has been guaranteed to return NET_XMIT_SUCCESS.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-45016?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `kgraft-patch-SLE12-SP5_Update_62` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 3-2.1 |

Products: Linux kernel.

## How do I fix CVE-2024-45016?

Apply the vendor's patch.

## Is CVE-2024-45016 being exploited?

There is no known exploitation of CVE-2024-45016 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-2024-45016 and fix it if it is affected.

What it is: CVE-2024-45016 is a high-severity use after free vulnerability in Linux kernel, published on 11 Sep 2024. 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-2024-45016 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-2024-45016/ (Markdown: https://insights.sbomify.com/CVE-2024-45016/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-45016
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-45016
- OSV: https://osv.dev/vulnerability/CVE-2024-45016

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-45016/
Summaries are generated and may contain mistakes; the official description above is the record.