# CVE-2026-89913: KVM: arm64: vgic-v3: take an LPI reference in vgic_v3_save_pending_tables

> A race condition in the Linux kernel's KVM arm64 VGIC implementation allows a use-after-free, potentially leading to code execution or privilege escalation.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/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:** 16 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-101282, BELL-CVE-2026-89913, DEBIAN-CVE-2026-89913, GHSA-x7mw-48gf-2rxm, UBUNTU-CVE-2026-89913

## What is CVE-2026-89913?

CVE-2026-89913 is a high-severity use after free vulnerability in Linux, published on 16 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:

KVM: arm64: vgic-v3: take an LPI reference in vgic_v3_save_pending_tables

vgic_v3_save_pending_tables() iterates dist->lpi_xa using xa_for_each()
and dereferences the returned struct vgic_irq in the loop body without
holding a reference on the LPI.

The xarray iterator only provides temporary RCU coverage while looking up
the current entry. That is not sufficient for this loop body, which reads
fields from struct vgic_irq and performs guest memory accesses before the
iteration completes.

A concurrent path can trigger this race: the irqfd cached injection path
(vgic_its_inject_cached_translation) obtains a transient LPI reference
via vgic_its_check_cache() without holding kvm->lock, vcpu->mutex,
config_lock, or its_lock. If guest ITS DISCARD then drops the cache and
ITE references under its_lock, the transient inject reference may become
the final one. When vgic_put_irq() drops it, the LPI is erased from
lpi_xa and freed via kfree_rcu(). Meanwhile, vgic_v3_save_pending_tables()
may still hold a stale pointer obtained from the xarray iterator and
dereference it after the RCU grace period completes.

Fix this by re-fetching each iterated LPI via vgic_get_irq(), which takes
a stable reference, and dropping it with vgic_put_irq() on all paths.
This matches the pattern already used by other lpi_xa iterators in the
vgic ITS code.

## Which versions are affected by CVE-2026-89913?


## How do I fix CVE-2026-89913?

Apply the vendor's patch.

## Is CVE-2026-89913 being exploited?

There is no known exploitation of CVE-2026-89913 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89913 and fix it if it is affected.

What it is: CVE-2026-89913 is a high-severity use after free vulnerability in Linux, published on 16 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-2026-89913 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-2026-89913/ (Markdown: https://insights.sbomify.com/CVE-2026-89913/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89913
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89913
- OSV: https://osv.dev/vulnerability/CVE-2026-89913

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89913/
Summaries are generated and may contain mistakes; the official description above is the record.