CVE-2021-3656
published 2022-03-04CVE-2021-3656: A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block)…
PriorityP345high8.8CVSS 3.1
AVLACLPRLUINSCCHIHAH
EPSS
0.66%
47.4th percentile
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
Affected
66 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 5.14.6-1 (bookworm) | linux 5.14.6-1 (bookworm) |
| fedoraproject | fedora | — | — |
| fedoraproject | fedora | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 5.10.46-5 | 5.10.46-5 |
| linux | linux_kernel | >= 0 < 5.14.6-1 | 5.14.6-1 |
| linux | linux_kernel | >= 0 < 5.14.6-1 | 5.14.6-1 |
| linux | linux_kernel | >= 0 < 5.14.6-1 | 5.14.6-1 |
| linux | linux_kernel | >= 0 < 4.15.0-156.163 | 4.15.0-156.163 |
| linux | linux_kernel | >= 0 < 5.4.0-84.94 | 5.4.0-84.94 |
| linux | linux_kernel | >= 0 < 4.4.0-214.246 | 4.4.0-214.246 |
| linux | linux_kernel | >= 0 < 4.15.0-156.163 | 4.15.0-156.163 |
| linux | linux_kernel | >= 0 < 5.4.0-84.94 | 5.4.0-84.94 |
| linux | linux_kernel | >= 4.13 < 4.14.245 | 4.14.245 |
| linux | linux_kernel | >= 4.15 < 4.19.205 | 4.19.205 |
| linux | linux_kernel | >= 4.20 < 5.4.142 | 5.4.142 |
| linux | linux_kernel | >= 5.11 < 5.13.12 | 5.13.12 |
| linux | linux_kernel | >= 5.5 < 5.10.60 | 5.10.60 |
| msrc | cm1_kernel_5.10.102.1-1_on_cbl_mariner_1.0 | — | — |
| redhat | 3scale_api_management | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux_desktop | — | — |
| redhat | enterprise_linux_eus | — | — |
| redhat | enterprise_linux_eus | — | — |
| redhat | enterprise_linux_eus | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
nvdv2.07.2HIGHAV:L/AC:L/Au:N/C:C/I:C/A:C
osv8.8HIGH
vendor_debian8.8HIGH
vendor_msrc8.8HIGH
vendor_redhat8.8HIGH
vendor_ubuntu8.8HIGH
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Microsoft
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nes
vendor_msrc·2022-03-08·CVSS 8.8
CVE-2021-3656 [HIGH] CWE-862 A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nes
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result the L2 guest would be allowed to read/write physical pages of the host resulting in a crash of the entire system leak of sensitive data or potential guest-to-host escape.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Lin
Ubuntu
Linux kernel (GCP) vulnerabilities
vendor_ubuntu·2021-09-17·CVSS 5.5
CVE-2021-38160 [MEDIUM] Linux kernel (GCP) vulnerabilities
Title: Linux kernel (GCP) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
Norbert Slusarek discovered that the CAN broadcast manger (bcm) protocol
implementati
Ubuntu
Linux kernel (OEM) vulnerabilities
vendor_ubuntu·2021-09-16·CVSS 7.0
CVE-2021-3653 [HIGH] Linux kernel (OEM) vulnerabilities
Title: Linux kernel (OEM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
Norbert Slusarek discovered a race condition in the CAN BCM networking
protocol of th
Ubuntu
Linux kernel (HWE) vulnerabilities
vendor_ubuntu·2021-09-16·CVSS 5.5
CVE-2021-3656 [MEDIUM] Linux kernel (HWE) vulnerabilities
Title: Linux kernel (HWE) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
USN-5071-1 fixed vulnerabilities in the Linux kernel for Ubuntu 20.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 20.04 LTS for Ubuntu
18.04 LTS.
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in
Ubuntu
Kernel Live Patch Security Notice
vendor_ubuntu·2021-09-13·CVSS 8.3
CVE-2021-3653 [HIGH] Kernel Live Patch Security Notice
Title: Kernel Live Patch Security Notice
Summary: Several security issues were fixed in the kernel.
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory.(CVE-2021-3653)
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory.(CVE-2021-3656)
Andy Nguyen discovered that the netfilter subsystem in the Linux kernel
contained an out-of-bo
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2021-09-09·CVSS 5.5
CVE-2021-3612 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
Norbert Slusarek discovered that the CAN broadcast manger (bcm) protocol
implementation in
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2021-09-08·CVSS 6.5
CVE-2021-3612 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
It was discovered that the Linux kernel did not properly enforce certain
types of entries i
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2021-09-08·CVSS 8.8
CVE-2021-3656 [HIGH] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
Instructions: After a standard system update you need to reboot your computer to make
all t
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2021-09-08·CVSS 5.5
CVE-2020-36311 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
It was discovered that the KVM hypervisor implementation for AMD processors
in the Linux ke
Red Hat
kernel: SVM nested virtualization issue in KVM (VMLOAD/VMSAVE)
vendor_redhat·2021-08-16·CVSS 8.8
CVE-2021-3656 [HIGH] CWE-862 kernel: SVM nested virtualization issue in KVM (VMLOAD/VMSAVE)
kernel: SVM nested virtualization issue in KVM (VMLOAD/VMSAVE)
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block
Debian
CVE-2021-3656: linux - A flaw was found in the KVM's AMD code for supporting SVM nested virtualization....
vendor_debian·2021·CVSS 8.8
CVE-2021-3656 [HIGH] CVE-2021-3656: linux - A flaw was found in the KVM's AMD code for supporting SVM nested virtualization....
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
Scope: local
bookworm: resolved (fixed in 5.14.6-1)
bullseye: resolved (fixed in 5.10.46-5)
forky: resolved (fixed in 5.14.6-1)
sid: resolved (fixed in 5.14.6-1)
trixie: resolved (fixed in 5.14.6-1)
OSV
CVE-2021-3656: A flaw was found in the KVM's AMD code for supporting SVM nested virtualization
osv·2022-03-04·CVSS 8.8
CVE-2021-3656 [HIGH] CVE-2021-3656: A flaw was found in the KVM's AMD code for supporting SVM nested virtualization
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
OSV
linux-gcp, linux-gcp-4.15 vulnerabilities
osv·2021-09-17·CVSS 5.5
CVE-2021-3656 [MEDIUM] linux-gcp, linux-gcp-4.15 vulnerabilities
linux-gcp, linux-gcp-4.15 vulnerabilities
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
Norbert Slusarek discovered that the CAN broadcast manger (bcm) protocol
implementation in the Linux kernel did not properly initialize memory in
some
OSV
linux-oem-5.13 vulnerabilities
osv·2021-09-16·CVSS 7.0
CVE-2021-3656 [HIGH] linux-oem-5.13 vulnerabilities
linux-oem-5.13 vulnerabilities
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
Norbert Slusarek discovered a race condition in the CAN BCM networking
protocol of the Linux kernel leading to multiple use-after-free
vulnerabilities. A local at
OSV
linux-hwe-5.4 vulnerabilities
osv·2021-09-16·CVSS 5.5
[MEDIUM] linux-hwe-5.4 vulnerabilities
linux-hwe-5.4 vulnerabilities
USN-5071-1 fixed vulnerabilities in the Linux kernel for Ubuntu 20.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 20.04 LTS for Ubuntu
18.04 LTS.
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portio
Kernel
KVM: x86: nSVM: don't copy virt_ext from vmcb12
kernel_security·2021-09-14·CVSS 8.8
CVE-2021-3653 [HIGH] KVM: x86: nSVM: don't copy virt_ext from vmcb12
KVM: x86: nSVM: don't copy virt_ext from vmcb12
These field correspond to features that we don't expose yet to L2
While currently there are no CVE worthy features in this field,
if AMD adds more features to this field, that could allow guest
escapes similar to CVE-2021-3653 and CVE-2021-3656.
Signed-off-by: Maxim Levitsky
Message-Id:
Cc: [email protected]
Signed-off-by: Paolo Bonzini
OSV
Kernel Live Patch Security Notice
osv·2021-09-13·CVSS 7.8
CVE-2021-3653 [HIGH] Kernel Live Patch Security Notice
Kernel Live Patch Security Notice
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory.(CVE-2021-3653)
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory.(CVE-2021-3656)
Andy Nguyen discovered that the netfilter subsystem in the Linux kernel
contained an out-of-bounds write in its setsockopt() implementation. A
local attacker cou
OSV
linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-hwe, linux-kvm, linux-oracle, linux-snapdragon vulnerabilities
osv·2021-09-09·CVSS 5.5
CVE-2021-3656 [MEDIUM] linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-hwe, linux-kvm, linux-oracle, linux-snapdragon vulnerabilities
linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-hwe, linux-kvm, linux-oracle, linux-snapdragon vulnerabilities
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
Norbert Slusarek discovered that the CAN bro
OSV
linux-azure-5.8, linux-oem-5.10 vulnerabilities
osv·2021-09-08·CVSS 8.8
CVE-2021-3656 [HIGH] linux-azure-5.8, linux-oem-5.10 vulnerabilities
linux-azure-5.8, linux-oem-5.10 vulnerabilities
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
OSV
linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-kvm, linux-oracle, linux-oracle-5.4 vulnerabiliti
osv·2021-09-08·CVSS 5.5
[MEDIUM] linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-kvm, linux-oracle, linux-oracle-5.4 vulnerabiliti
linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-kvm, linux-oracle, linux-oracle-5.4 vulnerabilities
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-20
OSV
linux, linux-aws, linux-aws-5.11, linux-azure, linux-azure-5.11, linux-gcp, linux-hwe-5.11, linux-kvm, linux-oracle, linux-oracle-5.11, linux-raspi vulnerabilities
osv·2021-09-08·CVSS 6.5
CVE-2021-3656 [MEDIUM] linux, linux-aws, linux-aws-5.11, linux-azure, linux-azure-5.11, linux-gcp, linux-hwe-5.11, linux-kvm, linux-oracle, linux-oracle-5.11, linux-raspi vulnerabilities
linux, linux-aws, linux-aws-5.11, linux-azure, linux-azure-5.11, linux-gcp, linux-hwe-5.11, linux-kvm, linux-oracle, linux-oracle-5.11, linux-raspi vulnerabilities
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
memory. (CVE-2021-3656)
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
It was discovered that the Li
Kernel
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
kernel_security·2021-08-16·CVSS 8.8
CVE-2021-3653 [HIGH] Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"Two nested virtualization fixes for AMD processors"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: nSVM: always intercept VMLOAD/VMSAVE when nested (CVE-2021-3656)
KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653)
Kernel
KVM: nSVM: always intercept VMLOAD/VMSAVE when nested (CVE-2021-3656)
kernel_security·2021-07-19·CVSS 8.8
CVE-2021-3656 [HIGH] KVM: nSVM: always intercept VMLOAD/VMSAVE when nested (CVE-2021-3656)
KVM: nSVM: always intercept VMLOAD/VMSAVE when nested (CVE-2021-3656)
If L1 disables VMLOAD/VMSAVE intercepts, and doesn't enable
Virtual VMLOAD/VMSAVE (currently not supported for the nested hypervisor),
then VMLOAD/VMSAVE must operate on the L1 physical memory, which is only
possible by making L0 intercept these instructions.
Failure to do so allowed the nested guest to run VMLOAD/VMSAVE unintercepted,
and thus read/write portions of the host physical memory.
Fixes: 89c8a4984fc9 ("KVM: SVM: Enable Virtual VMLOAD VMSAVE feature")
Suggested-by: Paolo Bonzini
Signed-off-by: Maxim Levitsky
Signed-off-by: Paolo Bonzini
No detection rules found.
No public exploits indexed.
https://bugzilla.redhat.com/show_bug.cgi?id=1983988https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=c7dfa4009965a9b2d7b329ee970eb8da0d32f0bchttps://github.com/torvalds/linux/commit/c7dfa4009965a9b2d7b329ee970eb8da0d32f0bchttps://www.openwall.com/lists/oss-security/2021/08/16/1https://bugzilla.redhat.com/show_bug.cgi?id=1983988https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=c7dfa4009965a9b2d7b329ee970eb8da0d32f0bchttps://github.com/torvalds/linux/commit/c7dfa4009965a9b2d7b329ee970eb8da0d32f0bchttps://www.openwall.com/lists/oss-security/2021/08/16/1
2022-03-04
Published