[USN-4890-1] Linux kernel vulnerabilities

========================================================================== Ubuntu Security Notice USN-4890-1 March 25, 2021
linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-gcp, linux-gcp-4.15, linux-hwe, linux-kvm, linux-oracle, linux-signed, linux-snapdragon vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 18.04 LTS – Ubuntu 16.04 LTS
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-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems – 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-gcp: Linux kernel for Google Cloud Platform (GCP) systems – linux-hwe: Linux hardware enablement (HWE) kernel
Details:
Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not properly compute a speculative execution limit on pointer arithmetic in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-27171)
Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not properly apply speculative execution limits on some pointer types. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-27170)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 18.04 LTS: linux-image-4.15.0-1015-dell300x 4.15.0-1015.19 linux-image-4.15.0-1068-oracle 4.15.0-1068.76 linux-image-4.15.0-1088-kvm 4.15.0-1088.90 linux-image-4.15.0-1096-gcp 4.15.0-1096.109 linux-image-4.15.0-1097-aws 4.15.0-1097.104 linux-image-4.15.0-1099-snapdragon 4.15.0-1099.108 linux-image-4.15.0-1111-azure 4.15.0-1111.123 linux-image-4.15.0-140-generic 4.15.0-140.144 linux-image-4.15.0-140-generic-lpae 4.15.0-140.144 linux-image-4.15.0-140-lowlatency 4.15.0-140.144 linux-image-aws-lts-18.04 4.15.0.1097.100 linux-image-azure-lts-18.04 4.15.0.1111.84 linux-image-dell300x 4.15.0.1015.17 linux-image-gcp-lts-18.04 4.15.0.1096.114 linux-image-generic 4.15.0.140.127 linux-image-generic-lpae 4.15.0.140.127 linux-image-kvm 4.15.0.1088.84 linux-image-lowlatency 4.15.0.140.127 linux-image-oracle-lts-18.04 4.15.0.1068.78 linux-image-powerpc-e500mc 4.15.0.140.127 linux-image-powerpc-smp 4.15.0.140.127 linux-image-powerpc64-emb 4.15.0.140.127 linux-image-powerpc64-smp 4.15.0.140.127 linux-image-snapdragon 4.15.0.1099.102 linux-image-virtual 4.15.0.140.127
Ubuntu 16.04 LTS: linux-image-4.15.0-1068-oracle 4.15.0-1068.76~16.04.1 linux-image-4.15.0-1096-gcp 4.15.0-1096.109~16.04.1 linux-image-4.15.0-1097-aws 4.15.0-1097.104~16.04.1 linux-image-4.15.0-1111-azure 4.15.0-1111.123~16.04.1 linux-image-4.15.0-140-generic 4.15.0-140.144~16.04.1 linux-image-4.15.0-140-generic-lpae 4.15.0-140.144~16.04.1 linux-image-4.15.0-140-lowlatency 4.15.0-140.144~16.04.1 linux-image-aws-hwe 4.15.0.1097.90 linux-image-azure 4.15.0.1111.102 linux-image-gcp 4.15.0.1096.97 linux-image-generic-hwe-16.04 4.15.0.140.135 linux-image-generic-lpae-hwe-16.04 4.15.0.140.135 linux-image-gke 4.15.0.1096.97 linux-image-lowlatency-hwe-16.04 4.15.0.140.135 linux-image-oem 4.15.0.140.135 linux-image-oracle 4.15.0.1068.56 linux-image-virtual-hwe-16.04 4.15.0.140.135
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-4890-1 CVE-2020-27170, CVE-2020-27171
Package Information: launchpad.net/ubuntu/+source/linux/4.15.0-140.144 launchpad.net/ubuntu/+source/linux-aws/4.15.0-1097.104 launchpad.net/ubuntu/+source/linux-azure-4.15/4.15.0-1111.123 launchpad.net/ubuntu/+source/linux-dell300x/4.15.0-1015.19 launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1096.109 launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1088.90 launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1068.76 launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1099.108 launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1097.104~16.04.1 launchpad.net/ubuntu/+source/linux-azure/4.15.0-1111.123~16.04.1 launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1096.109~16.04.1 launchpad.net/ubuntu/+source/linux-hwe/4.15.0-140.144~16.04.1 launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1068.76~16.04.1