# CVE-2026-81015: platform/x86/amd/pmc: Fix LPS0 and debugfs leaks when STB init fails

> A kernel bug in the AMD PMC driver causes memory corruption and system crashes when initialization fails, leading to denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-81015, DEBIAN-CVE-2026-81015, GHSA-4m25-x3hr-48wm, UBUNTU-CVE-2026-81015

## What is CVE-2026-81015?

CVE-2026-81015 is a high-severity memory corruption 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: Fix LPS0 and debugfs leaks when STB init fails

amd_pmc_probe() registers the LPS0 s2idle handler with
acpi_register_lps0_dev() and creates the driver's debugfs directory before
calling amd_stb_s2d_init(), which is the last step in probe that can fail.

When amd_stb_s2d_init() fails (for example the S2D telemetry region cannot
be ioremapped on a long-running system, or the SMU rejects the S2D setup)
the error path only calls pci_dev_put() and returns.  This leaves
amd_pmc_s2idle_dev_ops on the global lps0_s2idle_devops_head list and leaks
the debugfs directory, while the devm-managed resources backing the handler
are torn down.

Reloading the module then walks the corrupted list in
acpi_register_lps0_dev() and hits:

  list_add corruption. next->prev should be prev, but was NULL.
  kernel BUG at lib/list_debug.c:29!
   acpi_register_lps0_dev+0x44/0x80
   amd_pmc_probe+0x224/0x380 [amd_pmc]
   platform_probe+0x67/0x90

Even without a reload, the stale registration means the next s2idle
transition calls into torn-down driver state.

Unwind the debugfs directory and the LPS0 registration on the
amd_stb_s2d_init() error path.  acpi_unregister_lps0_dev() is safe to call
unconditionally here: it is guarded on the same conditions as
acpi_register_lps0_dev(), which is exactly what amd_pmc_remove() already
relies on.

## Which versions are affected by CVE-2026-81015?


## How do I fix CVE-2026-81015?

Apply the vendor's patch.

## Is CVE-2026-81015 being exploited?

There is no known exploitation of CVE-2026-81015 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81015 and fix it if it is affected.

What it is: CVE-2026-81015 is a high-severity memory corruption 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-2026-81015 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-2026-81015/ (Markdown: https://insights.sbomify.com/CVE-2026-81015/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81015
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81015
- OSV: https://osv.dev/vulnerability/CVE-2026-81015

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-81015/
Summaries are generated and may contain mistakes; the official description above is the record.