CVE-2021-47255

Summary

In the Linux kernel, the following vulnerability has been resolved:

kvm: LAPIC: Restore guard to prevent illegal APIC register access

Per the SDM, "any access that touches bytes 4 through 15 of an APIC register may cause undefined behavior and must not be executed." Worse, such an access in kvm_lapic_reg_read can result in a leak of kernel stack contents. Prior to commit 01402cf81051 ("kvm: LAPIC: write down valid APIC registers"), such an access was explicitly disallowed. Restore the guard that was removed in that commit.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux01402cf81051f796dac7c60ca11d6147153ca46a < bf99ea52970caeb4583bdba1192c1f9b53b12c84affected
LinuxLinux01402cf81051f796dac7c60ca11d6147153ca46a < 018685461a5b9a9a70e664ac77aef0d7415a3fd5affected
LinuxLinux01402cf81051f796dac7c60ca11d6147153ca46a < a2aff09807fbe4018c269d3773a629949058b210affected
LinuxLinux01402cf81051f796dac7c60ca11d6147153ca46a < 218bf772bddd221489c38dde6ef8e917131161f6affected
LinuxLinux5.3affected
LinuxLinux0 < 5.3unaffected
LinuxLinux5.4.128 <= 5.4.*unaffected
LinuxLinux5.10.46 <= 5.10.*unaffected
LinuxLinux5.12.13 <= 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