Detections
Analytics
CVE-2021-29657
high
Description
arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.
References
https://security.netapp.com/advisory/ntap-20210902-0008/
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12
https://bugs.chromium.org/p/project-zero/issues/detail?id=2177
http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html