CVE-2021-47062

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinuxad73109ae7ec30d5bfb76be108e304f9f0af4829 < bd0cced2ae93195668f983d443f7f17e8efd24d2affected
LinuxLinuxad73109ae7ec30d5bfb76be108e304f9f0af4829 < ba7bf5d6336aa9c0d977b161bfa420c56d46ee40affected
LinuxLinuxad73109ae7ec30d5bfb76be108e304f9f0af4829 < c36b16d29f3af5f32fc1b2a3401bf48f71cabee1affected
LinuxLinux5.11affected
LinuxLinux0 < 5.11unaffected
LinuxLinux5.11.21 <= 5.11.*unaffected
LinuxLinux5.12.4 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References