# CVE-2026-89972: nvme: add missing SRCU grace period in error path

> A missing SRCU grace period in the Linux kernel NVMe driver error path allows a use-after-free, potentially leading to code execution or system crashes.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-101552, BELL-CVE-2026-89972, DEBIAN-CVE-2026-89972, GHSA-cjx2-56hv-4vc4, UBUNTU-CVE-2026-89972

## What is CVE-2026-89972?

CVE-2026-89972 is a critical use after free vulnerability in Linux, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

nvme: add missing SRCU grace period in error path

nvme_alloc_ns() error path at out_unlink_ns removes ns from the
namespace head siblings list with list_del_rcu(&ns->siblings) but
does not wait for SRCU readers before freeing the namespace struct.
Multipath code iterates the head->list under srcu_read_lock() in
nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent
reader can still hold a reference to ns when kfree(ns) runs.

The normal removal path in nvme_ns_remove() correctly calls
synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for
in-progress readers. Add the same grace period in the error path.

## Which versions are affected by CVE-2026-89972?


## How do I fix CVE-2026-89972?

Apply the vendor's patch.

## Is CVE-2026-89972 being exploited?

There is no known exploitation of CVE-2026-89972 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89972 and fix it if it is affected.

What it is: CVE-2026-89972 is a critical use after free vulnerability in Linux, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-89972 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-2026-89972/ (Markdown: https://insights.sbomify.com/CVE-2026-89972/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89972
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89972
- OSV: https://osv.dev/vulnerability/CVE-2026-89972

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89972/
Summaries are generated and may contain mistakes; the official description above is the record.