# CVE-2024-40983: tipc: force a dst refcount before doing decryption

> A missing reference count in the Linux kernel TIPC decryption path can cause a crash, leading to denial of service.

- **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:** 12 Jul 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-40983, DEBIAN-CVE-2024-40983, GHSA-rvwv-8rrq-q84r, UBUNTU-CVE-2024-40983

## What is CVE-2024-40983?

CVE-2024-40983 is a critical vulnerability in Linux kernel, published on 12 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:

tipc: force a dst refcount before doing decryption

As it says in commit 3bc07321ccc2 ("xfrm: Force a dst refcount before
entering the xfrm type handlers"):

"Crypto requests might return asynchronous. In this case we leave the
 rcu protected region, so force a refcount on the skb's destination
 entry before we enter the xfrm type input/output handlers."

On TIPC decryption path it has the same problem, and skb_dst_force()
should be called before doing decryption to avoid a possible crash.

Shuang reported this issue when this warning is triggered:

  [] WARNING: include/net/dst.h:337 tipc_sk_rcv+0x1055/0x1ea0 [tipc]
  [] Kdump: loaded Tainted: G W --------- - - 4.18.0-496.el8.x86_64+debug
  [] Workqueue: crypto cryptd_queue_worker
  [] RIP: 0010:tipc_sk_rcv+0x1055/0x1ea0 [tipc]
  [] Call Trace:
  [] tipc_sk_mcast_rcv+0x548/0xea0 [tipc]
  [] tipc_rcv+0xcf5/0x1060 [tipc]
  [] tipc_aead_decrypt_done+0x215/0x2e0 [tipc]
  [] cryptd_aead_crypt+0xdb/0x190
  [] cryptd_queue_worker+0xed/0x190
  [] process_one_work+0x93d/0x17e0

## Which versions are affected by CVE-2024-40983?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-40983?

Apply the vendor's patch.

## Is CVE-2024-40983 being exploited?

There is no known exploitation of CVE-2024-40983 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-2024-40983 and fix it if it is affected.

What it is: CVE-2024-40983 is a critical vulnerability in Linux kernel, published on 12 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-2024-40983 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-2024-40983/ (Markdown: https://insights.sbomify.com/CVE-2024-40983/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-40983
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-40983
- OSV: https://osv.dev/vulnerability/CVE-2024-40983

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-40983/
Summaries are generated and may contain mistakes; the official description above is the record.