# CVE-2026-81016: platform/x86/amd/pmc: Propagate SMU errors and validate S2D address

> An attacker with local access could trigger a kernel warning and potential denial of service by causing the AMD PMC driver to map physical address zero due to unchecked SMU errors.

- **Severity:** High 7.7 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-100124, BELL-CVE-2026-81016, DEBIAN-CVE-2026-81016, GHSA-wv8r-9hh3-p28x, UBUNTU-CVE-2026-81016

## What is CVE-2026-81016?

CVE-2026-81016 is a high-severity vulnerability in Linux, published on 11 Sep 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:

platform/x86/amd/pmc: Propagate SMU errors and validate S2D address

amd_stb_s2d_init() discards the return value of several S2D SMU commands.
When the SMU refuses a command (e.g. "SMU cmd failed. err: 0xff") the
failure is only noticed indirectly - if at all - and reported as -EIO,
masking the real error.

More seriously, the S2D_PHYS_ADDR_LOW/HIGH return values are ignored, so
on failure phys_addr_low/hi are left uninitialised and the assembled
address is passed straight to devm_ioremap().  When the SMU leaves them at
zero this maps physical address 0 and trips the ioremap-on-RAM warning:

  amd_pmc AMDI000B:00: SMU cmd failed. err: 0xff
  ioremap on RAM at 0x0000000000000000 - 0x0000000000ffffff
  WARNING: CPU: 13 PID: 4592 at arch/x86/mm/ioremap.c:...

Check the return value of each SMU command and propagate it, and reject a
zero physical address before calling devm_ioremap().

## Which versions are affected by CVE-2026-81016?


## How do I fix CVE-2026-81016?

Apply the vendor's patch.

## Is CVE-2026-81016 being exploited?

There is no known exploitation of CVE-2026-81016 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81016 and fix it if it is affected.

What it is: CVE-2026-81016 is a high-severity vulnerability in Linux, published on 11 Sep 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-2026-81016 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-2026-81016/ (Markdown: https://insights.sbomify.com/CVE-2026-81016/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81016
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81016
- OSV: https://osv.dev/vulnerability/CVE-2026-81016

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-81016/
Summaries are generated and may contain mistakes; the official description above is the record.