CVE-2026-46147

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

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