CVE-2021-46977

KVM: VMX: Disable preemption when probing user return MSRs

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.

5.5

CVSS

Severity: Medium

CVSS 3.1 •

EPSS 0.05%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/31f29749ee970c251b3a7e5b914108425940d089	patch
https://git.kernel.org/stable/c/5adcdeb57007ccf8ab7ac20bf787ffb6fafb1a94	patch
https://git.kernel.org/stable/c/e3ea1895df719c4ef87862501bb10d95f4177bed	patch
https://git.kernel.org/stable/c/5104d7ffcf24749939bea7fdb5378d186473f890	patch

Frequently Asked Questions

What is the severity of CVE-2021-46977?: CVE-2021-46977 has been scored as a medium severity vulnerability.
How to fix CVE-2021-46977?: To fix CVE-2021-46977, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-46977 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2021-46977 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-46977?: CVE-2021-46977 affects Linux Linux, Linux Linux.

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