# CVE-2026-46147: KVM: arm64: Fix pin leak and publication ordering in __pkvm_init_vcpu()

> A race condition and memory leak in Linux KVM arm64 vCPU initialization can cause resource exhaustion or inconsistent state, requiring kernel patching.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 28 May 2026
- **Updated:** 14 Jun 2026
- **Also known as:** AZL-88908, BELL-CVE-2026-46147, DEBIAN-CVE-2026-46147, GHSA-m978-f9gm-gj2j, ROOT-OS-DEBIAN-11-CVE-2026-46147, ROOT-OS-DEBIAN-12-CVE-2026-46147, ROOT-OS-DEBIAN-13-CVE-2026-46147, ROOT-OS-UBUNTU-2204-CVE-2026-46147, ROOT-OS-UBUNTU-2404-CVE-2026-46147, UBUNTU-CVE-2026-46147

## What is CVE-2026-46147?

CVE-2026-46147 is a medium-severity vulnerability in Linux kernel, published on 28 May 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: Fix pin leak and publication ordering in __pkvm_init_vcpu()

Two bugs exist in the vCPU initialisation path:

1. If a check fails after hyp_pin_shared_mem() succeeds, the cleanup
   path jumps to 'unlock' without calling unpin_host_vcpu() or
   unpin_host_sve_state(), permanently leaking pin references on the
   host vCPU and SVE state pages.

   Extract a register_hyp_vcpu() helper that performs the checks and
   the store. When register_hyp_vcpu() returns an error, call
   unpin_host_vcpu() and unpin_host_sve_state() inline before falling
   through to the existing 'unlock' label.

2. register_hyp_vcpu() publishes the new vCPU pointer into
   'hyp_vm->vcpus[]' with a bare store, allowing a concurrent caller
   of pkvm_load_hyp_vcpu() to observe a partially initialised vCPU
   object.

   Ensure the store uses smp_store_release() and the load uses
   smp_load_acquire(). While 'vm_table_lock' currently serialises the
   store and the load, these barriers ensure the reader sees the fully
   initialised 'hyp_vcpu' object even if there were a lockless path or
   if the lock's own ordering guarantees were insufficient for nested
   object initialization.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-46147?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46147?

Apply the vendor's patch.

## Is CVE-2026-46147 being exploited?

There is no known exploitation of CVE-2026-46147 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46147 and fix it if it is affected.

What it is: CVE-2026-46147 is a medium-severity vulnerability in Linux kernel, published on 28 May 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-2026-46147 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-46147/ (Markdown: https://insights.sbomify.com/CVE-2026-46147/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46147
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46147
- OSV: https://osv.dev/vulnerability/CVE-2026-46147

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46147/
Summaries are generated and may contain mistakes; the official description above is the record.