UBUNTU-CVE-2026-46147: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix pin leak and publication ordering in pkvminitvcpu() Two bugs exist in the vCPU initialisation path: 1. If a check fails after hyppinsharedmem() succeeds, the cleanup path jumps to 'unlock' without calling unpinhostvcpu() or unpinhostsvestate(), permanently leaking pin references on the host vCPU and SVE state pages. Extract a registerhypvcpu() helper that performs the checks and the store. When registerhypvcpu() returns an error, call unpinhostvcpu() and unpinhostsvestate() inline before falling through to the existing 'unlock' label. 2. registerhypvcpu() publishes the new vCPU pointer into 'hypvm->vcpus[]' with a bare store, allowing a concurrent caller of pkvmloadhypvcpu() to observe a partially initialised vCPU object. Ensure the store uses smpstorerelease() and the load uses smploadacquire(). While 'vmtablelock' currently serialises the store and the load, these barriers ensure the reader sees the fully initialised 'hypvcpu' object even if there were a lockless path or if the lock's own ordering guarantees were insufficient for nested object initialization.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-28.28~24.04.1 - Upgrade
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ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-28.28 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1009.9 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1010.10 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1009.9 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1008.8 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1003.4 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1010.10 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
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ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2016.16 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1009.9 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1008.8 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-28.28.1 - Compensating control
Fix __pkvm_init_vcpu() publication ordering by extracting a register_hyp_vcpu() helper that performs the checks and publishes the vCPU pointer with smp_store_release(); make pkvm_load_hyp_vcpu() use smp_load_acquire().
- Compensating control
Fix the pin-reference leak by calling unpin_host_vcpu() and unpin_host_sve_state() inline when register_hyp_vcpu() returns an error after hyp_pin_shared_mem() succeeds, before falling through to the existing unlock cleanup path.