# CVE-2024-45009: mptcp: pm: only decrement add_addr_accepted for MPJ req

> A logic error in the Linux kernel's MPTCP path manager can cause a kernel warning and potential denial of service when removing subflow endpoints.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:** 11 Sep 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-49197, AZL-49224, BELL-CVE-2024-45009, DEBIAN-CVE-2024-45009, GHSA-rhqc-rfxh-qj7g, ROOT-OS-DEBIAN-11-CVE-2024-45009, UBUNTU-CVE-2024-45009

## What is CVE-2024-45009?

CVE-2024-45009 is a high-severity denial of service vulnerability in Linux kernel, published on 11 Sep 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:

mptcp: pm: only decrement add_addr_accepted for MPJ req

Adding the following warning ...

  WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)

... before decrementing the add_addr_accepted counter helped to find a
bug when running the "remove single subflow" subtest from the
mptcp_join.sh selftest.

Removing a 'subflow' endpoint will first trigger a RM_ADDR, then the
subflow closure. Before this patch, and upon the reception of the
RM_ADDR, the other peer will then try to decrement this
add_addr_accepted. That's not correct because the attached subflows have
not been created upon the reception of an ADD_ADDR.

A way to solve that is to decrement the counter only if the attached
subflow was an MP_JOIN to a remote id that was not 0, and initiated by
the host receiving the RM_ADDR.

## Which versions are affected by CVE-2024-45009?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-45009?

Apply the vendor's patch.

## Is CVE-2024-45009 being exploited?

There is no known exploitation of CVE-2024-45009 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-2024-45009 and fix it if it is affected.

What it is: CVE-2024-45009 is a high-severity denial of service vulnerability in Linux kernel, published on 11 Sep 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-2024-45009 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-2024-45009/ (Markdown: https://insights.sbomify.com/CVE-2024-45009/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-45009
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-45009
- OSV: https://osv.dev/vulnerability/CVE-2024-45009

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-45009/
Summaries are generated and may contain mistakes; the official description above is the record.