UBUNTU-CVE-2021-29657
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.
02 / AFFECTED SOFTWARE
Affected packages
23 explicit affected versions
6 explicit affected versions
10 explicit affected versions
44 explicit affected versions
16 explicit affected versions
4 explicit affected versions
38 explicit affected versions
13 explicit affected versions
12 explicit affected versions
33 explicit affected versions
43 explicit affected versions
10 explicit affected versions
50 explicit affected versions
7 explicit affected versions
9 explicit affected versions
10 explicit affected versions
6 explicit affected versions
12 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES