# CVE-2024-40992: RDMA/rxe: Fix responder length checking for UD request packets

> A flaw in the Linux kernel RDMA subsystem allows remote attackers to cause a denial of service by sending malformed UD request packets that trigger an error state.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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-2024-40992, DEBIAN-CVE-2024-40992, GHSA-pq93-v2j7-gw4w, UBUNTU-CVE-2024-40992

## What is CVE-2024-40992?

CVE-2024-40992 is a high-severity denial of service 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:

RDMA/rxe: Fix responder length checking for UD request packets

According to the IBA specification:
If a UD request packet is detected with an invalid length, the request
shall be an invalid request and it shall be silently dropped by
the responder. The responder then waits for a new request packet.

commit 689c5421bfe0 ("RDMA/rxe: Fix incorrect responder length checking")
defers responder length check for UD QPs in function `copy_data`.
But it introduces a regression issue for UD QPs.

When the packet size is too large to fit in the receive buffer.
`copy_data` will return error code -EINVAL. Then `send_data_in`
will return RESPST_ERR_MALFORMED_WQE. UD QP will transfer into
ERROR state.

## Which versions are affected by CVE-2024-40992?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-40992?

Apply the vendor's patch.

## Is CVE-2024-40992 being exploited?

There is no known exploitation of CVE-2024-40992 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-2024-40992 and fix it if it is affected.

What it is: CVE-2024-40992 is a high-severity denial of service 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-2024-40992 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-2024-40992/ (Markdown: https://insights.sbomify.com/CVE-2024-40992/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-40992
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-40992
- OSV: https://osv.dev/vulnerability/CVE-2024-40992

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-40992/
Summaries are generated and may contain mistakes; the official description above is the record.