# CVE-2023-52513: RDMA/siw: Fix connection failure handling

> A NULL pointer dereference in the Linux kernel RDMA subsystem allows attackers to cause a denial of service via connection failure handling.

- **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:** 2 Mar 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-52513, DEBIAN-CVE-2023-52513, GHSA-2m3h-p692-qjp7, UBUNTU-CVE-2023-52513

## What is CVE-2023-52513?

CVE-2023-52513 is a high-severity vulnerability in Linux kernel, published on 2 Mar 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/siw: Fix connection failure handling

In case immediate MPA request processing fails, the newly
created endpoint unlinks the listening endpoint and is
ready to be dropped. This special case was not handled
correctly by the code handling the later TCP socket close,
causing a NULL dereference crash in siw_cm_work_handler()
when dereferencing a NULL listener. We now also cancel
the useless MPA timeout, if immediate MPA request
processing fails.

This patch furthermore simplifies MPA processing in general:
Scheduling a useless TCP socket read in sk_data_ready() upcall
is now surpressed, if the socket is already moved out of
TCP_ESTABLISHED state.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-52513?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52513?

Apply the vendor's patch.

## Is CVE-2023-52513 being exploited?

There is no known exploitation of CVE-2023-52513 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-2023-52513 and fix it if it is affected.

What it is: CVE-2023-52513 is a high-severity vulnerability in Linux kernel, published on 2 Mar 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-2023-52513 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-2023-52513/ (Markdown: https://insights.sbomify.com/CVE-2023-52513/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52513
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52513
- OSV: https://osv.dev/vulnerability/CVE-2023-52513

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52513/
Summaries are generated and may contain mistakes; the official description above is the record.