# CVE-2026-43410: firmware: stratix10-rsu: Fix NULL pointer dereference when RSU is disabled

> A NULL pointer dereference in the Stratix10 RSU driver causes a kernel panic when RSU is disabled in firmware, 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:** 8 May 2026
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2026-43410, GHSA-q6cw-2hr2-g93j, ROOT-OS-UBUNTU-2204-CVE-2026-43410, ROOT-OS-UBUNTU-2404-CVE-2026-43410, UBUNTU-CVE-2026-43410

## What is CVE-2026-43410?

CVE-2026-43410 is a medium-severity vulnerability in Linux kernel, published on 8 May 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 pointer dereference when RSU is disabled

When the Remote System Update (RSU) isn't enabled in the First Stage
Boot Loader (FSBL), the driver encounters a NULL pointer dereference when
excute svc_normal_to_secure_thread() thread, resulting in a kernel panic:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
Mem abort info:
...
Data abort info:
...
[0000000000000008] user address but active_mm is swapper
Internal error: Oops: 0000000096000004 [#1]  SMP
Modules linked in:
CPU: 0 UID: 0 PID: 79 Comm: svc_smc_hvc_thr Not tainted 6.19.0-rc8-yocto-standard+ #59 PREEMPT
Hardware name: SoCFPGA Stratix 10 SoCDK (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : svc_normal_to_secure_thread+0x38c/0x990
lr : svc_normal_to_secure_thread+0x144/0x990
...
Call trace:
 svc_normal_to_secure_thread+0x38c/0x990 (P)
 kthread+0x150/0x210
 ret_from_fork+0x10/0x20
Code: 97cfc113 f9400260 aa1403e1 f9400400 (f9400402)
---[ end trace 0000000000000000 ]---

The issue occurs because rsu_send_async_msg() fails when RSU is not enabled
in firmware, causing the channel to be freed via stratix10_svc_free_channel().
However, the probe function continues execution and registers
svc_normal_to_secure_thread(), which subsequently attempts to access the
already-freed channel, triggering the NULL pointer dereference.

Fix this by properly cleaning up the async client and returning early on
failure, preventing the thread from being used with an invalid channel.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-43410?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43410?

Apply the vendor's patch.

## Is CVE-2026-43410 being exploited?

There is no known exploitation of CVE-2026-43410 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-2026-43410 and fix it if it is affected.

What it is: CVE-2026-43410 is a medium-severity vulnerability in Linux kernel, published on 8 May 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-2026-43410 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-2026-43410/ (Markdown: https://insights.sbomify.com/CVE-2026-43410/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43410
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43410
- OSV: https://osv.dev/vulnerability/CVE-2026-43410

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43410/
Summaries are generated and may contain mistakes; the official description above is the record.