[USN-4946-1] Linux kernel vulnerabilities

========================================================================== Ubuntu Security Notice USN-4946-1 May 11, 2021
linux, linux-aws, lnux-aws-hwe, linux-azure, inux-azure-4.15, linux-dell300x, linux-gcp, linux-hwe, linux-gcp-4.15, linux-kvm, linux-oracle, linux-raspi2, 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-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-raspi2: Linux kernel for Raspberry Pi (V8) systems – linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors – linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems – linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems – linux-hwe: Linux hardware enablement (HWE) kernel – linux-azure: Linux kernel for Microsoft Azure Cloud systems
Details:
It was discovered that the DRM subsystem in the Linux kernel contained double-free vulnerabilities. A privileged attacker could possibly use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-20292)
Olivier Benjamin, Norbert Manthey, Martin Mazein, and Jan H. Schönherr discovered that the Xen paravirtualization backend in the Linux kernel did not properly propagate errors to frontend drivers in some situations. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26930)
Jan Beulich discovered that multiple Xen backends in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26931)
Jan Beulich discovered that the Xen netback backend in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-28038)
It was discovered that the Xen paravirtualization backend in the Linux kernel did not properly deallocate memory in some situations. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2021-28688)
It was discovered that the Freescale Gianfar Ethernet driver for the Linux kernel did not properly handle receive queue overrun when jumbo frames were enabled in some situations. An attacker could use this to cause a denial of service (system crash). (CVE-2021-29264)
It was discovered that the USB/IP driver in the Linux kernel contained race conditions during the update of local and shared status. An attacker could use this to cause a denial of service (system crash). (CVE-2021-29265)
It was discovered that a race condition existed in the netfilter subsystem of the Linux kernel when replacing tables. A local attacker could use this to cause a denial of service (system crash). (CVE-2021-29650)
Arnd Bergmann discovered that the video4linux subsystem in the Linux kernel did not properly deallocate memory in some situations. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2021-30002)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 18.04 LTS: linux-image-4.15.0-1018-dell300x 4.15.0-1018.22 linux-image-4.15.0-1071-oracle 4.15.0-1071.79 linux-image-4.15.0-1085-raspi2 4.15.0-1085.90 linux-image-4.15.0-1091-kvm 4.15.0-1091.93 linux-image-4.15.0-1099-gcp 4.15.0-1099.112 linux-image-4.15.0-1102-aws 4.15.0-1102.109 linux-image-4.15.0-1102-snapdragon 4.15.0-1102.111 linux-image-4.15.0-1114-azure 4.15.0-1114.127 linux-image-4.15.0-143-generic 4.15.0-143.147 linux-image-4.15.0-143-generic-lpae 4.15.0-143.147 linux-image-4.15.0-143-lowlatency 4.15.0-143.147 linux-image-aws-lts-18.04 4.15.0.1102.105 linux-image-azure-lts-18.04 4.15.0.1114.87 linux-image-dell300x 4.15.0.1018.20 linux-image-gcp-lts-18.04 4.15.0.1099.117 linux-image-generic 4.15.0.143.130 linux-image-generic-lpae 4.15.0.143.130 linux-image-kvm 4.15.0.1091.87 linux-image-lowlatency 4.15.0.143.130 linux-image-oracle-lts-18.04 4.15.0.1071.81 linux-image-raspi2 4.15.0.1085.82 linux-image-snapdragon 4.15.0.1102.105 linux-image-virtual 4.15.0.143.130
Ubuntu 16.04 ESM: linux-image-4.15.0-1071-oracle 4.15.0-1071.79~16.04.1 linux-image-4.15.0-1099-gcp 4.15.0-1099.112~16.04.1 linux-image-4.15.0-1102-aws 4.15.0-1102.109~16.04.1 linux-image-4.15.0-143-generic 4.15.0-143.147~16.04.3 linux-image-4.15.0-143-lowlatency 4.15.0-143.147~16.04.3 linux-image-aws-hwe 4.15.0.1102.93 linux-image-gcp 4.15.0.1099.100 linux-image-generic-hwe-16.04 4.15.0.143.139 linux-image-gke 4.15.0.1099.100 linux-image-lowlatency-hwe-16.04 4.15.0.143.139 linux-image-oem 4.15.0.143.139 linux-image-oracle 4.15.0.1071.59 linux-image-virtual-hwe-16.04 4.15.0.143.139
Ubuntu 14.04 ESM: linux-image-4.15.0-1114-azure 4.15.0-1114.127~14.04.1 linux-image-azure 4.15.0.1114.87
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-4946-1 CVE-2021-20292, CVE-2021-26930, CVE-2021-26931, CVE-2021-28038, CVE-2021-28688, CVE-2021-29264, CVE-2021-29265, CVE-2021-29650, CVE-2021-30002
Package Information: launchpad.net/ubuntu/+source/linux/4.15.0-143.147 launchpad.net/ubuntu/+source/linux-aws/4.15.0-1102.109 launchpad.net/ubuntu/+source/linux-azure-4.15/4.15.0-1114.127 launchpad.net/ubuntu/+source/linux-dell300x/4.15.0-1018.22 launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1099.112 launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1091.93 launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1071.79 launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1085.90 launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1102.111