# CVE-2026-98002: iommu/amd: Fix ineffective error check in nested domain allocation

> An integer overflow in AMD IOMMU nested domain allocation causes error checks to fail, potentially leading to undefined behavior or resource exhaustion.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/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:** 25 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-98002, GHSA-38jm-2gpc-m9wh, UBUNTU-CVE-2026-98002

## What is CVE-2026-98002?

CVE-2026-98002 is a high-severity 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:

iommu/amd: Fix ineffective error check in nested domain allocation

amd_iommu_pdom_id_alloc() returns an int: a domain ID on success, or the
negative errno from ida_alloc_range() when the ID space is exhausted or
memory is short.  amd_iommu_alloc_domain_nested() stores that return value
in gdom_info->hdom_id, which is a u32, and only then tests it:

	gdom_info->hdom_id = amd_iommu_pdom_id_alloc();
	if (gdom_info->hdom_id <= 0) {

The assignment discards the sign, so -ENOSPC becomes 0xffffffe4 and the
test never fires.  The nested domain is then set up with a host domain ID
that was never allocated, instead of the allocation failing with -ENOSPC.

Keep the value in an int, test it there, and store it only once it is
known to be valid, which is what the other amd_iommu_pdom_id_alloc()
callers already do.

## Which versions are affected by CVE-2026-98002?


## How do I fix CVE-2026-98002?

Apply the vendor's patch.

## Is CVE-2026-98002 being exploited?

There is no known exploitation of CVE-2026-98002 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98002 and fix it if it is affected.

What it is: CVE-2026-98002 is a high-severity 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-2026-98002 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-2026-98002/ (Markdown: https://insights.sbomify.com/CVE-2026-98002/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98002
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98002
- OSV: https://osv.dev/vulnerability/CVE-2026-98002

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98002/
Summaries are generated and may contain mistakes; the official description above is the record.