Vulnerability CVE-2021-46977
Published: 2024-02-28

Description:
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.

 References:
https://git.kernel.org/stable/c/31f29749ee970c251b3a7e5b914108425940d089
https://git.kernel.org/stable/c/5adcdeb57007ccf8ab7ac20bf787ffb6fafb1a94
https://git.kernel.org/stable/c/e3ea1895df719c4ef87862501bb10d95f4177bed
https://git.kernel.org/stable/c/5104d7ffcf24749939bea7fdb5378d186473f890
Copyright 2026, cxsecurity.com

 

Back to Top