title: KVM: SVM: Use online_vcpus, not created_vcpus, to iterate over vCPUs
description: In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Use online_vcpus, not created_vcpus, to iterate over vCPUs
Use the kvm_for_each_vcpu() helper to iterate over vCPUs when encrypting
VMSAs for SEV, which effectively switches to use online_vcpus instead of
created_vcpus.  This fixes a possible null-pointer dereference as
created_vcpus does not guarantee a vCPU exists, since it is updated at
the very beginning of KVM_CREATE_VCPU.  created_vcpus exists to allow the
bulk of vCPU creation to run in parallel, while still correctly
restricting the max number of max vCPUs.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: ad73109ae7ec, lessThan: bd0cced2ae93, status: affected, versionType: git
version: ad73109ae7ec, lessThan: ba7bf5d6336a, status: affected, versionType: git
version: ad73109ae7ec, lessThan: c36b16d29f3a, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.11, status: affected
version: 0, lessThan: 5.11, status: unaffected, versionType: custom
version: 5.11.21, lessThanOrEqual: 5.11.*, status: unaffected, versionType: custom
version: 5.12.4, lessThanOrEqual: 5.12.*, status: unaffected, versionType: custom
version: 5.13, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
