USN-5071-1: Linux kernel vulnerabilities
8 September 2021
Several security issues were fixed in the Linux kernel.
Releases
Packages
- linux - Linux kernel
- linux-aws - Linux kernel for Amazon Web Services (AWS) systems
- linux-aws-5.4 - Linux kernel for Amazon Web Services (AWS) systems
- linux-azure - Linux kernel for Microsoft Azure Cloud systems
- linux-azure-5.4 - Linux kernel for Microsoft Azure cloud systems
- linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
- linux-gcp-5.4 - Linux kernel for Google Cloud Platform (GCP) systems
- linux-gke - Linux kernel for Google Container Engine (GKE) systems
- linux-gke-5.4 - Linux kernel for Google Container Engine (GKE) systems
- linux-gkeop - Linux kernel for Google Container Engine (GKE) systems
- linux-gkeop-5.4 - Linux kernel for Google Container Engine (GKE) systems
- linux-kvm - Linux kernel for cloud environments
- linux-oracle - Linux kernel for Oracle Cloud systems
- linux-oracle-5.4 - Linux kernel for Oracle Cloud systems
Details
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 kernel did not ensure enough processing time was given to
perform cleanups of large SEV VMs. A local attacker could use this to cause
a denial of service (soft lockup). (CVE-2020-36311)
It was discovered that the KVM hypervisor implementation in the Linux
kernel did not properly perform reference counting in some situations,
leading to a use-after-free vulnerability. An attacker who could start and
control a VM could possibly use this to expose sensitive information or
execute arbitrary code. (CVE-2021-22543)
Murray McAllister discovered that the joystick device interface in the
Linux kernel did not properly validate data passed via an ioctl(). A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code on systems with a joystick device
registered. (CVE-2021-3612)
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.04
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linux-image-5.4.0-1052-gke
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5.4.0-1052.55
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linux-image-5.4.0-84-generic-lpae
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5.4.0-84.94
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linux-image-5.4.0-1052-gcp
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5.4.0-1052.56
-
linux-image-gkeop
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5.4.0.1023.26
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linux-image-virtual
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5.4.0.84.88
-
linux-image-generic
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5.4.0.84.88
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linux-image-5.4.0-84-generic
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5.4.0-84.94
-
linux-image-5.4.0-1023-gkeop
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5.4.0-1023.24
-
linux-image-oem-osp1
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5.4.0.84.88
-
linux-image-5.4.0-1046-kvm
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5.4.0-1046.48
-
linux-image-azure-lts-20.04
-
5.4.0.1058.56
-
linux-image-5.4.0-1058-azure
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5.4.0-1058.60
-
linux-image-gkeop-5.4
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5.4.0.1023.26
-
linux-image-5.4.0-1054-oracle
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5.4.0-1054.58
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linux-image-gcp-lts-20.04
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5.4.0.1052.62
-
linux-image-aws-lts-20.04
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5.4.0.1056.59
-
linux-image-5.4.0-1056-aws
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5.4.0-1056.59
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linux-image-5.4.0-84-lowlatency
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5.4.0-84.94
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linux-image-gke
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5.4.0.1052.62
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linux-image-oracle-lts-20.04
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5.4.0.1054.54
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linux-image-gke-5.4
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5.4.0.1052.62
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linux-image-kvm
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5.4.0.1046.45
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linux-image-oem
-
5.4.0.84.88
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linux-image-generic-lpae
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5.4.0.84.88
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linux-image-lowlatency
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5.4.0.84.88
Ubuntu 18.04
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linux-image-5.4.0-1052-gke
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5.4.0-1052.55~18.04.1
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linux-image-5.4.0-1052-gcp
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5.4.0-1052.56~18.04.1
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linux-image-5.4.0-1023-gkeop
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5.4.0-1023.24~18.04.1
-
linux-image-aws
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5.4.0.1056.39
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linux-image-5.4.0-1058-azure
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5.4.0-1058.60~18.04.1
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linux-image-gkeop-5.4
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5.4.0.1023.24~18.04.24
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linux-image-5.4.0-1054-oracle
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5.4.0-1054.58~18.04.1
-
linux-image-azure
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5.4.0.1058.38
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linux-image-5.4.0-1056-aws
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5.4.0-1056.59~18.04.1
-
linux-image-gcp
-
5.4.0.1052.38
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linux-image-oracle
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5.4.0.1054.58~18.04.34
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linux-image-gke-5.4
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5.4.0.1052.55~18.04.17
After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.