[USN-5116-1] Linux kernel vulnerabilities

========================================================================== Ubuntu Security Notice USN-5116-1 October 20, 2021
linux, linux-bluefield, linux-gcp-5.4, linux-hwe-5.4, linux-kvm vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 20.04 LTS – Ubuntu 18.04 LTS
Summary:
Several security issues were fixed in the Linux kernel.
Software Description: – linux: Linux kernel – linux-bluefield: Linux kernel for NVIDIA BlueField platforms – linux-kvm: Linux kernel for cloud environments – linux-gcp-5.4: Linux kernel for Google Cloud Platform (GCP) systems – linux-hwe-5.4: Linux hardware enablement (HWE) kernel
Details:
It was discovered that a race condition existed in the Atheros Ath9k WiFi driver in the Linux kernel. An attacker could possibly use this to expose sensitive information (WiFi network traffic). (CVE-2020-3702)
Alois Wohlschlager discovered that the overlay file system in the Linux kernel did not restrict private clones in some situations. An attacker could use this to expose sensitive information. (CVE-2021-3732)
It was discovered that the KVM hypervisor implementation in the Linux kernel did not properly compute the access permissions for shadow pages in some situations. A local attacker could use this to cause a denial of service. (CVE-2021-38198)
It was discovered that the Xilinx 10/100 Ethernet Lite device driver in the Linux kernel could report pointer addresses in some situations. An attacker could use this information to ease the exploitation of another vulnerability. (CVE-2021-38205)
It was discovered that the ext4 file system in the Linux kernel contained a race condition when writing xattrs to an inode. A local attacker could use this to cause a denial of service or possibly gain administrative privileges. (CVE-2021-40490)
It was discovered that the 6pack network protocol driver in the Linux kernel did not properly perform validation checks. A privileged attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-42008)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.04 LTS: linux-image-5.4.0-1020-bluefield 5.4.0-1020.23 linux-image-5.4.0-1048-kvm 5.4.0-1048.50 linux-image-5.4.0-89-generic 5.4.0-89.100 linux-image-5.4.0-89-generic-lpae 5.4.0-89.100 linux-image-5.4.0-89-lowlatency 5.4.0-89.100 linux-image-bluefield 5.4.0.1020.21 linux-image-generic 5.4.0.89.93 linux-image-generic-lpae 5.4.0.89.93 linux-image-kvm 5.4.0.1048.47 linux-image-lowlatency 5.4.0.89.93 linux-image-oem 5.4.0.89.93 linux-image-oem-osp1 5.4.0.89.93 linux-image-virtual 5.4.0.89.93
Ubuntu 18.04 LTS: linux-image-5.4.0-1055-gcp 5.4.0-1055.59~18.04.1 linux-image-5.4.0-89-generic 5.4.0-89.100~18.04.1 linux-image-5.4.0-89-generic-lpae 5.4.0-89.100~18.04.1 linux-image-5.4.0-89-lowlatency 5.4.0-89.100~18.04.1 linux-image-gcp 5.4.0.1055.41 linux-image-generic-hwe-18.04 5.4.0.89.100~18.04.79 linux-image-generic-lpae-hwe-18.04 5.4.0.89.100~18.04.79 linux-image-lowlatency-hwe-18.04 5.4.0.89.100~18.04.79 linux-image-oem 5.4.0.89.100~18.04.79 linux-image-oem-osp1 5.4.0.89.100~18.04.79 linux-image-snapdragon-hwe-18.04 5.4.0.89.100~18.04.79 linux-image-virtual-hwe-18.04 5.4.0.89.100~18.04.79
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-5116-1 CVE-2020-3702, CVE-2021-3732, CVE-2021-38198, CVE-2021-38205, CVE-2021-40490, CVE-2021-42008
Package Information: launchpad.net/ubuntu/+source/linux/5.4.0-89.100 launchpad.net/ubuntu/+source/linux-bluefield/5.4.0-1020.23 launchpad.net/ubuntu/+source/linux-kvm/5.4.0-1048.50 launchpad.net/ubuntu/+source/linux-gcp-5.4/5.4.0-1055.59~18.04.1 launchpad.net/ubuntu/+source/linux-hwe-5.4/5.4.0-89.100~18.04.1