[USN-5073-1] Linux kernel vulnerabilities

========================================================================== Ubuntu Security Notice USN-5073-1 September 09, 2021
linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-hwe, linux-kvm, linux-oracle, linux-snapdragon vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 18.04 LTS – Ubuntu 16.04 ESM – Ubuntu 14.04 ESM
Summary:
Several security issues were fixed in the Linux kernel.
Software Description: – linux: Linux kernel – linux-aws: Linux kernel for Amazon Web Services (AWS) systems – linux-azure-4.15: Linux kernel for Microsoft Azure Cloud systems – linux-dell300x: Linux kernel for Dell 300x platforms – linux-kvm: Linux kernel for cloud environments – linux-oracle: Linux kernel for Oracle Cloud systems – linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors – linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems – linux-azure: Linux kernel for Microsoft Azure Cloud systems – linux-hwe: Linux hardware enablement (HWE) kernel
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)
Norbert Slusarek discovered that the CAN broadcast manger (bcm) protocol implementation in the Linux kernel did not properly initialize memory in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-34693)
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)
It was discovered that the Virtio console implementation in the Linux kernel did not properly validate input lengths in some situations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-38160)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 18.04 LTS: linux-image-4.15.0-1027-dell300x 4.15.0-1027.32 linux-image-4.15.0-1080-oracle 4.15.0-1080.88 linux-image-4.15.0-1099-kvm 4.15.0-1099.101 linux-image-4.15.0-1111-aws 4.15.0-1111.118 linux-image-4.15.0-1112-snapdragon 4.15.0-1112.121 linux-image-4.15.0-1123-azure 4.15.0-1123.136 linux-image-4.15.0-156-generic 4.15.0-156.163 linux-image-4.15.0-156-generic-lpae 4.15.0-156.163 linux-image-4.15.0-156-lowlatency 4.15.0-156.163 linux-image-aws-lts-18.04 4.15.0.1111.114 linux-image-azure-lts-18.04 4.15.0.1123.96 linux-image-dell300x 4.15.0.1027.29 linux-image-generic 4.15.0.156.145 linux-image-generic-lpae 4.15.0.156.145 linux-image-kvm 4.15.0.1099.95 linux-image-lowlatency 4.15.0.156.145 linux-image-oracle-lts-18.04 4.15.0.1080.90 linux-image-snapdragon 4.15.0.1112.115 linux-image-virtual 4.15.0.156.145
Ubuntu 16.04 ESM: linux-image-4.15.0-1080-oracle 4.15.0-1080.88~16.04.1 linux-image-4.15.0-1111-aws 4.15.0-1111.118~16.04.1 linux-image-4.15.0-1123-azure 4.15.0-1123.136~16.04.1 linux-image-4.15.0-156-generic 4.15.0-156.163~16.04.1 linux-image-4.15.0-156-lowlatency 4.15.0-156.163~16.04.1 linux-image-aws-hwe 4.15.0.1111.102 linux-image-azure 4.15.0.1123.114 linux-image-generic-hwe-16.04 4.15.0.156.149 linux-image-lowlatency-hwe-16.04 4.15.0.156.149 linux-image-oem 4.15.0.156.149 linux-image-oracle 4.15.0.1080.68 linux-image-virtual-hwe-16.04 4.15.0.156.149
Ubuntu 14.04 ESM: linux-image-4.15.0-1123-azure 4.15.0-1123.136~14.04.1 linux-image-azure 4.15.0.1123.96
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.
References: ubuntu.com/security/notices/USN-5073-1 CVE-2021-34693, CVE-2021-3612, CVE-2021-3653, CVE-2021-3656, CVE-2021-38160
Package Information: launchpad.net/ubuntu/+source/linux/4.15.0-156.163 launchpad.net/ubuntu/+source/linux-aws/4.15.0-1111.118 launchpad.net/ubuntu/+source/linux-azure-4.15/4.15.0-1123.136 launchpad.net/ubuntu/+source/linux-dell300x/4.15.0-1027.32 launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1099.101 launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1080.88 launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1112.121