CVE-2021-46977

Summary

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

KVM: VMX: Disable preemption when probing user return MSRs

Disable preemption when probing a user return MSR via RDSMR/WRMSR. If the MSR holds a different value per logical CPU, the WRMSR could corrupt the host's value if KVM is preempted between the RDMSR and WRMSR, and then rescheduled on a different CPU.

Opportunistically land the helper in common x86, SVM will use the helper in a future commit.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux4be5341026246870818e28b53202b001426a5aec < 31f29749ee970c251b3a7e5b914108425940d089affected
LinuxLinux4be5341026246870818e28b53202b001426a5aec < 5adcdeb57007ccf8ab7ac20bf787ffb6fafb1a94affected
LinuxLinux4be5341026246870818e28b53202b001426a5aec < e3ea1895df719c4ef87862501bb10d95f4177bedaffected
LinuxLinux4be5341026246870818e28b53202b001426a5aec < 5104d7ffcf24749939bea7fdb5378d186473f890affected
LinuxLinux5.5affected
LinuxLinux0 < 5.5unaffected
LinuxLinux5.10.38 <= 5.10.*unaffected
LinuxLinux5.11.22 <= 5.11.*unaffected
LinuxLinux5.12.5 <= 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