[USN-5014-1] Linux kernel vulnerability

========================================================================== Ubuntu Security Notice USN-5014-1 July 20, 2021
linux, linux-aws, linux-azure, linux-gcp, linux-gke-5.3, linux-hwe, linux-lts-xenial, linux-kvm, linux-oracle, linux-raspi, linux-raspi2-5.3 vulnerability ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 21.04 – Ubuntu 18.04 LTS – Ubuntu 16.04 ESM – Ubuntu 14.04 ESM
Summary:
The system could be made to run programs as an administrator.
Software Description: – linux: Linux kernel – linux-aws: Linux kernel for Amazon Web Services (AWS) systems – linux-azure: Linux kernel for Microsoft Azure Cloud systems – linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems – linux-kvm: Linux kernel for cloud environments – linux-oracle: Linux kernel for Oracle Cloud systems – linux-raspi: Linux kernel for Raspberry Pi (V8) systems – linux-gke-5.3: Linux kernel for Google Container Engine (GKE) systems – linux-hwe: Linux hardware enablement (HWE) kernel – linux-raspi2-5.3: Linux kernel for Raspberry Pi (V8) systems – linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty
Details:
It was discovered that the virtual file system implementation in the Linux kernel contained an unsigned to signed integer conversion error. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code.
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 21.04: linux-image-5.11.0-1012-azure 5.11.0-1012.13 linux-image-5.11.0-1012-kvm 5.11.0-1012.13 linux-image-5.11.0-1013-oracle 5.11.0-1013.14 linux-image-5.11.0-1014-aws 5.11.0-1014.15 linux-image-5.11.0-1014-gcp 5.11.0-1014.16 linux-image-5.11.0-1015-raspi 5.11.0-1015.16 linux-image-5.11.0-1015-raspi-nolpae 5.11.0-1015.16 linux-image-5.11.0-25-generic 5.11.0-25.27 linux-image-5.11.0-25-generic-64k 5.11.0-25.27 linux-image-5.11.0-25-generic-lpae 5.11.0-25.27 linux-image-5.11.0-25-lowlatency 5.11.0-25.27 linux-image-aws 5.11.0.1014.15 linux-image-azure 5.11.0.1012.13 linux-image-gcp 5.11.0.1014.14 linux-image-generic 5.11.0.25.27 linux-image-generic-64k 5.11.0.25.27 linux-image-generic-lpae 5.11.0.25.27 linux-image-gke 5.11.0.1014.14 linux-image-kvm 5.11.0.1012.13 linux-image-lowlatency 5.11.0.25.27 linux-image-oem-20.04 5.11.0.25.27 linux-image-oracle 5.11.0.1013.14 linux-image-raspi 5.11.0.1015.13 linux-image-raspi-nolpae 5.11.0.1015.13 linux-image-virtual 5.11.0.25.27
Ubuntu 18.04 LTS: linux-image-5.3.0-1042-raspi2 5.3.0-1042.44 linux-image-5.3.0-1045-gke 5.3.0-1045.48 linux-image-5.3.0-76-generic 5.3.0-76.72 linux-image-5.3.0-76-lowlatency 5.3.0-76.72 linux-image-gke-5.3 5.3.0.1045.28 linux-image-gkeop-5.3 5.3.0.76.133 linux-image-raspi2-hwe-18.04 5.3.0.1042.31
Ubuntu 16.04 ESM: linux-image-4.4.0-1095-kvm 4.4.0-1095.104 linux-image-4.4.0-1130-aws 4.4.0-1130.144 linux-image-4.4.0-212-generic 4.4.0-212.244 linux-image-4.4.0-212-lowlatency 4.4.0-212.244 linux-image-aws 4.4.0.1130.135 linux-image-generic 4.4.0.212.219 linux-image-kvm 4.4.0.1095.93 linux-image-lowlatency 4.4.0.212.219 linux-image-virtual 4.4.0.212.219
Ubuntu 14.04 ESM: linux-image-3.13.0-186-generic 3.13.0-186.237 linux-image-3.13.0-186-generic-lpae 3.13.0-186.237 linux-image-3.13.0-186-lowlatency 3.13.0-186.237 linux-image-3.13.0-186-powerpc-e500 3.13.0-186.237 linux-image-3.13.0-186-powerpc-e500mc 3.13.0-186.237 linux-image-3.13.0-186-powerpc-smp 3.13.0-186.237 linux-image-3.13.0-186-powerpc64-emb 3.13.0-186.237 linux-image-3.13.0-186-powerpc64-smp 3.13.0-186.237 linux-image-4.4.0-1094-aws 4.4.0-1094.99 linux-image-4.4.0-212-generic 4.4.0-212.244~14.04.1 linux-image-4.4.0-212-lowlatency 4.4.0-212.244~14.04.1 linux-image-aws 4.4.0.1094.92 linux-image-generic 3.13.0.186.195 linux-image-generic-lpae 3.13.0.186.195 linux-image-generic-lts-xenial 4.4.0.212.185 linux-image-generic-pae 3.13.0.186.195 linux-image-highbank 3.13.0.186.195 linux-image-lowlatency 3.13.0.186.195 linux-image-lowlatency-lts-xenial 4.4.0.212.185 linux-image-lowlatency-pae 3.13.0.186.195 linux-image-omap 3.13.0.186.195 linux-image-powerpc-e500 3.13.0.186.195 linux-image-powerpc-e500mc 3.13.0.186.195 linux-image-powerpc-smp 3.13.0.186.195 linux-image-powerpc64-emb 3.13.0.186.195 linux-image-powerpc64-smp 3.13.0.186.195 linux-image-server 3.13.0.186.195 linux-image-virtual 3.13.0.186.195 linux-image-virtual-lts-xenial 4.4.0.212.185
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-5014-1 CVE-2021-33909
Package Information: launchpad.net/ubuntu/+source/linux/5.11.0-25.27 launchpad.net/ubuntu/+source/linux-aws/5.11.0-1014.15 launchpad.net/ubuntu/+source/linux-azure/5.11.0-1012.13 launchpad.net/ubuntu/+source/linux-gcp/5.11.0-1014.16 launchpad.net/ubuntu/+source/linux-kvm/5.11.0-1012.13 launchpad.net/ubuntu/+source/linux-oracle/5.11.0-1013.14 launchpad.net/ubuntu/+source/linux-raspi/5.11.0-1015.16 launchpad.net/ubuntu/+source/linux-gke-5.3/5.3.0-1045.48 launchpad.net/ubuntu/+source/linux-hwe/5.3.0-76.72 launchpad.net/ubuntu/+source/linux-raspi2-5.3/5.3.0-1042.44