# CVE-2026-97947: x86/amd_node: Fix potential NULL pointer dereference

> A local attacker can trigger a NULL pointer dereference in the Linux kernel's AMD node driver, causing a system crash.

- **Severity:** Not scored
- **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 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-97947, DEBIAN-CVE-2026-97947, GHSA-xj5r-4m42-gc82, UBUNTU-CVE-2026-97947

## What is CVE-2026-97947?

CVE-2026-97947 is a vulnerability in Linux, published on 25 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:

x86/amd_node: Fix potential NULL pointer dereference

amd_smn_read/write() are exported functions around __amd_smn_rw(), so
they are always available even if amd_smn_init() fails. In that case,
'amd_roots' is NULL and __amd_smn_rw() will access uninitialized memory.

Then, commit:

  83518453074d ("x86/amd_node: Add SMN offsets to exclusive region access")

added the 'smn_exclusive' flag, which indicated the calls to
pci_request_config_region_exclusive() succeeded, to prevent
concurrent userspace access.

Commit:

  0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")

re-ordered initialization so pci_request_config_region_exclusive() is
called earlier and a failure exits amd_smn_init() before allocating
'amd_roots'. The setting of 'smn_exclusive' moved to the end of
amd_smn_init(), after 'amd_roots' is allocated. It became redundant
and can be removed.

Replace 'smn_exclusive' with directly checking 'amd_roots', to fix a
potential NULL pointer dereference and to simplify the logic.

  [ bp: Reorg commit message, touchup comment. ]
  [ mingo: Rebase & further touchups. ]

## Which versions are affected by CVE-2026-97947?


## How do I fix CVE-2026-97947?

Apply the vendor's patch.

## Is CVE-2026-97947 being exploited?

There is no known exploitation of CVE-2026-97947 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97947 and fix it if it is affected.

What it is: CVE-2026-97947 is a vulnerability in Linux, published on 25 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-2026-97947 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-2026-97947/ (Markdown: https://insights.sbomify.com/CVE-2026-97947/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97947
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97947
- OSV: https://osv.dev/vulnerability/CVE-2026-97947

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97947/
Summaries are generated and may contain mistakes; the official description above is the record.