# CVE-2026-53204: firmware: stratix10-rsu: Fix NULL deref on rsu_send_msg() timeout in probe

> A NULL pointer dereference in the Stratix10 RSU driver probe function can cause a kernel crash, leading to denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jun 2026
- **Updated:** 25 Jun 2026
- **Also known as:** DEBIAN-CVE-2026-53204, GHSA-7vgh-484p-pv5r, UBUNTU-CVE-2026-53204

## What is CVE-2026-53204?

CVE-2026-53204 is a medium-severity vulnerability in Linux kernel, published on 25 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

firmware: stratix10-rsu: Fix NULL deref on rsu_send_msg() timeout in probe

rsu_send_msg() can return -ETIMEDOUT when
wait_for_completion_interruptible_timeout() fires while the SMC call is still
pending. In stratix10_rsu_probe(), the error paths for COMMAND_RSU_DCMF_VERSION,
COMMAND_RSU_DCMF_STATUS, COMMAND_RSU_MAX_RETRY and COMMAND_RSU_GET_SPT_TABLE
call stratix10_svc_free_channel() - which sets chan->scl to NULL - but then
fall through and queue the next request on the same channel. The next svc
kthread that runs will dereference pdata->chan->scl in its receive callback
path, triggering a NULL pointer dereference identical to the one fixed by
commit c45f7263100c ("firmware: stratix10-rsu: Fix NULL pointer dereference
when RSU is disabled") for the COMMAND_RSU_STATUS path.

Apply the same cleanup pattern to the remaining failure paths: remove the
async client, free the channel, and return early so no further messages are
queued on a channel whose scl has been cleared.

While at it, clean up stratix10_rsu_probe() in two ways without changing
behavior:

- Drop redundant zero-initialization of fields already cleared by
  devm_kzalloc(): client.receive_cb, status.* and spt0/1_address
  (INVALID_SPT_ADDRESS is 0x0).

- Replace five identical 3-line error-cleanup blocks
  (stratix10_svc_remove_async_client() + stratix10_svc_free_channel() +
  return ret) with goto labels (remove_async_client, free_channel),
  matching the standard kernel resource-unwinding pattern and making it
  easier to extend the probe sequence without forgetting matching
  cleanup.

Also move init_completion() next to mutex_init() so sync-primitive
initialization is grouped before anything that could trigger a
callback.

---
v2: Add a minor clean-up of the function stratix10_rsu_probe() to have a
    centralize exit for all the rsu_send_async_msg() and rsu_send_msg().

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-53204?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53204?

Apply the vendor's patch.

## Is CVE-2026-53204 being exploited?

There is no known exploitation of CVE-2026-53204 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-2026-53204 and fix it if it is affected.

What it is: CVE-2026-53204 is a medium-severity vulnerability in Linux kernel, published on 25 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53204 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-2026-53204/ (Markdown: https://insights.sbomify.com/CVE-2026-53204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53204
- OSV: https://osv.dev/vulnerability/CVE-2026-53204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53204/
Summaries are generated and may contain mistakes; the official description above is the record.