# CVE-2026-98354: RDMA/mad: Fix receive buffer leak when PKey enforcement fails

> Remote attackers can cause memory leaks in the Linux kernel RDMA subsystem by sending invalid MADs, leading to resource exhaustion and denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106290, BELL-CVE-2026-98354, DEBIAN-CVE-2026-98354, GHSA-q823-95hw-ffc6, UBUNTU-CVE-2026-98354

## What is CVE-2026-98354?

CVE-2026-98354 is a denial of service vulnerability in Linux, published on 6 Oct 2026. 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/mad: Fix receive buffer leak when PKey enforcement fails

ib_mad_complete_recv() initializes mad_recv_wc->rmpp_list and then runs
ib_mad_enforce_security() before linking recv_buf onto that list.  On
failure it calls ib_free_recv_mad(), which only walks rmpp_list and frees
the ib_mad_private of every buffer found there.  As the list is still
empty at that point, nothing is freed at all.

The caller cannot clean up either: ib_mad_recv_done() sets recv to NULL
right after ib_mad_complete_recv() returns, assuming the MAD layer took
ownership of the buffer.  Every MAD that fails the PKey check therefore
leaks one ib_mad_private (about 300 bytes per IB port MAD, ~2K for OPA),
and a remote node can trigger this repeatedly by sending MADs with a
wrong PKey.

Link recv_buf onto rmpp_list right after the list is initialized, so the
error path has something to free.

## Which versions are affected by CVE-2026-98354?


## How do I fix CVE-2026-98354?

Apply the vendor's patch.

## Is CVE-2026-98354 being exploited?

There is no known exploitation of CVE-2026-98354 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98354 and fix it if it is affected.

What it is: CVE-2026-98354 is a denial of service vulnerability in Linux, published on 6 Oct 2026. 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-2026-98354 in the wild and no public exploit code.

Affected product: Linux. 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-2026-98354/ (Markdown: https://insights.sbomify.com/CVE-2026-98354/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98354
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98354
- OSV: https://osv.dev/vulnerability/CVE-2026-98354

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98354/
Summaries are generated and may contain mistakes; the official description above is the record.