Описание
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Use the active VMCB's MSR bitmap when checking if MSR is intercepted
Use the MSR permission bitmap of the active VMCB instead of assuming that
KVM is always using vmcb02's bitmap when L2 is active, as KVM uses msrpm02
if and only if L1 wants to intercept MSR accesses, i.e. if and only if KVM
needs to merge msprm01 with msrpm12.
Don't bother tracking the virtual address of the bitmap that's being used,
as __va() is cheap on x86, and caching the virtual address would introduce
yet another source of potentially stale information.
A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem for AMD processors (SVM). During nested virtualization, KVM incorrectly checked whether Model-Specific Register (MSR) accesses were intercepted by referencing the wrong control structure's permission bitmap. A malicious guest could exploit this behavior to bypass register interception controls, potentially leading to unauthorized hardware state manipulation or a denial of service (DoS).
Отчет
This vulnerability is rated as Important because an attacker operating within a nested virtual machine can circumvent register interception boundaries, leading to potential hypervisor compromise or host denial of service. The risk qualifies for this severity rating due to the cross-boundary escape potential from an unprivileged guest into the host kernel environment. Exploitation is strictly constrained to AMD hardware platforms configured to run nested KVM virtualization, meaning Intel-based deployments and hypervisors operating without nested virtualization enabled remain unaffected.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 9 | kernel | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Affected |
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Дополнительная информация
Статус:
EPSS
8.8 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Use the active VMCB's MSR bitmap when checking if MSR is intercepted Use the MSR permission bitmap of the active VMCB instead of assuming that KVM is always using vmcb02's bitmap when L2 is active, as KVM uses msrpm02 if and only if L1 wants to intercept MSR accesses, i.e. if and only if KVM needs to merge msprm01 with msrpm12. Don't bother tracking the virtual address of the bitmap that's being used, as __va() is cheap on x86, and caching the virtual address would introduce yet another source of potentially stale information.
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Use the active VMCB's MSR bitmap when checking if MSR is intercepted Use the MSR permission bitmap of the active VMCB instead of assuming that KVM is always using vmcb02's bitmap when L2 is active, as KVM uses msrpm02 if and only if L1 wants to intercept MSR accesses, i.e. if and only if KVM needs to merge msprm01 with msrpm12. Don't bother tracking the virtual address of the bitmap that's being used, as __va() is cheap on x86, and caching the virtual address would introduce yet another source of potentially stale information.
KVM: SVM: Use the active VMCB's MSR bitmap when checking if MSR is intercepted
In the Linux kernel, the following vulnerability has been resolved: K ...
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Use the active VMCB's MSR bitmap when checking if MSR is intercepted Use the MSR permission bitmap of the active VMCB instead of assuming that KVM is always using vmcb02's bitmap when L2 is active, as KVM uses msrpm02 if and only if L1 wants to intercept MSR accesses, i.e. if and only if KVM needs to merge msprm01 with msrpm12. Don't bother tracking the virtual address of the bitmap that's being used, as __va() is cheap on x86, and caching the virtual address would introduce yet another source of potentially stale information.
EPSS
8.8 High
CVSS3