[USN-5113-1] Linux kernel vulnerabilities

========================================================================== Ubuntu Security Notice USN-5113-1 October 19, 2021
linux, linux-aws, linux-aws-5.11, linux-azure, linux-azure-5.11, linux-gcp, linux-gcp-5.11, linux-hwe-5.11, linux-kvm, linux-raspi vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 21.04 – Ubuntu 20.04 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: 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-raspi: Linux kernel for Raspberry Pi systems – linux-aws-5.11: Linux kernel for Amazon Web Services (AWS) systems – linux-azure-5.11: Linux kernel for Microsoft Azure cloud systems – linux-gcp-5.11: Linux kernel for Google Cloud Platform (GCP) systems – linux-hwe-5.11: 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 btrfs file system in the Linux kernel did not properly handle removing a non-existent device id. An attacker with CAP_SYS_ADMIN could use this to cause a denial of service. (CVE-2021-3739)
It was discovered that the Qualcomm IPC Router protocol implementation in the Linux kernel did not properly validate metadata in some situations. A local attacker could use this to cause a denial of service (system crash) or expose sensitive information. (CVE-2021-3743)
It was discovered that the virtual terminal (vt) device implementation in the Linux kernel contained a race condition in its ioctl handling that lead to an out-of-bounds read vulnerability. A local attacker could possibly use this to expose sensitive information. (CVE-2021-3753)
It was discovered that the BPF subsystem in the Linux kernel contained an integer overflow in its hash table implementation. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-38166)
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 21.04: linux-image-5.11.0-1018-kvm 5.11.0-1018.19 linux-image-5.11.0-1020-aws 5.11.0-1020.21 linux-image-5.11.0-1020-azure 5.11.0-1020.21 linux-image-5.11.0-1021-gcp 5.11.0-1021.23 linux-image-5.11.0-1021-raspi 5.11.0-1021.22 linux-image-5.11.0-1021-raspi-nolpae 5.11.0-1021.22 linux-image-5.11.0-38-generic 5.11.0-38.42 linux-image-5.11.0-38-generic-64k 5.11.0-38.42 linux-image-5.11.0-38-generic-lpae 5.11.0-38.42 linux-image-5.11.0-38-lowlatency 5.11.0-38.42 linux-image-aws 5.11.0.1020.21 linux-image-azure 5.11.0.1020.21 linux-image-gcp 5.11.0.1021.21 linux-image-generic 5.11.0.38.39 linux-image-generic-64k 5.11.0.38.39 linux-image-generic-lpae 5.11.0.38.39 linux-image-gke 5.11.0.1021.21 linux-image-kvm 5.11.0.1018.19 linux-image-lowlatency 5.11.0.38.39 linux-image-oem-20.04 5.11.0.38.39 linux-image-raspi 5.11.0.1021.19 linux-image-raspi-nolpae 5.11.0.1021.19 linux-image-virtual 5.11.0.38.39
Ubuntu 20.04 LTS: linux-image-5.11.0-1020-aws 5.11.0-1020.21~20.04.2 linux-image-5.11.0-1020-azure 5.11.0-1020.21~20.04.1 linux-image-5.11.0-1021-gcp 5.11.0-1021.23~20.04.1 linux-image-5.11.0-38-generic 5.11.0-38.42~20.04.1 linux-image-5.11.0-38-generic-64k 5.11.0-38.42~20.04.1 linux-image-5.11.0-38-generic-lpae 5.11.0-38.42~20.04.1 linux-image-5.11.0-38-lowlatency 5.11.0-38.42~20.04.1 linux-image-aws 5.11.0.1020.21~20.04.19 linux-image-azure-edge 5.11.0.1020.21~20.04.19 linux-image-gcp 5.11.0.1021.23~20.04.20 linux-image-generic-64k-hwe-20.04 5.11.0.38.42~20.04.17 linux-image-generic-hwe-20.04 5.11.0.38.42~20.04.17 linux-image-generic-lpae-hwe-20.04 5.11.0.38.42~20.04.17 linux-image-lowlatency-hwe-20.04 5.11.0.38.42~20.04.17 linux-image-virtual-hwe-20.04 5.11.0.38.42~20.04.17
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-5113-1 CVE-2020-3702, CVE-2021-3732, CVE-2021-3739, CVE-2021-3743, CVE-2021-3753, CVE-2021-38166, CVE-2021-40490, CVE-2021-42008
Package Information: launchpad.net/ubuntu/+source/linux/5.11.0-38.42 launchpad.net/ubuntu/+source/linux-aws/5.11.0-1020.21 launchpad.net/ubuntu/+source/linux-azure/5.11.0-1020.21 launchpad.net/ubuntu/+source/linux-gcp/5.11.0-1021.23 launchpad.net/ubuntu/+source/linux-kvm/5.11.0-1018.19 launchpad.net/ubuntu/+source/linux-raspi/5.11.0-1021.22 launchpad.net/ubuntu/+source/linux-aws-5.11/5.11.0-1020.21~20.04.2 launchpad.net/ubuntu/+source/linux-azure-5.11/5.11.0-1020.21~20.04.1 launchpad.net/ubuntu/+source/linux-gcp-5.11/5.11.0-1021.23~20.04.1 launchpad.net/ubuntu/+source/linux-hwe-5.11/5.11.0-38.42~20.04.1