[USN-4984-1] Linux kernel vulnerabilities

========================================================================== Ubuntu Security Notice USN-4984-1 June 04, 2021
linux, linux-aws, linux-azure, linux-gcp, linux-hwe-5.8, linux-kvm, linux-oracle vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 20.10 – 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-oracle: Linux kernel for Oracle Cloud systems – linux-hwe-5.8: Linux hardware enablement (HWE) kernel
Details:
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 Realtek RTL8188EU Wireless device driver in the Linux kernel did not properly validate ssid lengths in some situations. An attacker could use this to cause a denial of service (system crash). (CVE-2021-28660)
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 fuse user space file system implementation in the Linux kernel did not properly handle bad inodes in some situations. A local attacker could possibly use this to cause a denial of service. (CVE-2021-28950)
John Stultz discovered that the audio driver for Qualcomm SDM845 systems in the Linux kernel did not properly validate port ID numbers. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-28952)
Zygo Blaxell discovered that the btrfs file system implementation in the Linux kernel contained a race condition during certain cloning operations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-28964)
Vince Weaver discovered that the perf subsystem in the Linux kernel did not properly handle certain PEBS records properly for some Intel Haswell processors. A local attacker could use this to cause a denial of service (system crash). (CVE-2021-28971)
It was discovered that the RPA PCI Hotplug driver implementation in the Linux kernel did not properly handle device name writes via sysfs, leading to a buffer overflow. A privileged attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-28972)
It was discovered that the Qualcomm IPC router implementation in the Linux kernel did not properly initialize memory passed to user space. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-29647)
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)
Dan Carpenter discovered that the block device manager (dm) implementation in the Linux kernel contained a buffer overflow in the ioctl for listing devices. A privileged local attacker could use this to cause a denial of service (system crash). (CVE-2021-31916)
It was discovered that the CIPSO implementation in the Linux kernel did not properly perform reference counting in some situations, leading to use- after-free vulnerabilities. An attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33033)
马哲宇 discovered that the IEEE 1394 (Firewire) nosy packet sniffer driver in the Linux kernel did not properly perform reference counting in some situations, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-3483)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.10: linux-image-5.8.0-1028-kvm 5.8.0-1028.30 linux-image-5.8.0-1031-oracle 5.8.0-1031.32 linux-image-5.8.0-1032-gcp 5.8.0-1032.34 linux-image-5.8.0-1033-azure 5.8.0-1033.35 linux-image-5.8.0-1035-aws 5.8.0-1035.37 linux-image-5.8.0-55-generic 5.8.0-55.62 linux-image-5.8.0-55-generic-64k 5.8.0-55.62 linux-image-5.8.0-55-generic-lpae 5.8.0-55.62 linux-image-5.8.0-55-lowlatency 5.8.0-55.62 linux-image-aws 5.8.0.1035.37 linux-image-azure 5.8.0.1033.33 linux-image-gcp 5.8.0.1032.32 linux-image-generic 5.8.0.55.60 linux-image-generic-64k 5.8.0.55.60 linux-image-generic-lpae 5.8.0.55.60 linux-image-gke 5.8.0.1032.32 linux-image-kvm 5.8.0.1028.30 linux-image-lowlatency 5.8.0.55.60 linux-image-oracle 5.8.0.1031.30 linux-image-virtual 5.8.0.55.60
Ubuntu 20.04 LTS: linux-image-5.8.0-55-generic 5.8.0-55.62~20.04.1 linux-image-5.8.0-55-generic-64k 5.8.0-55.62~20.04.1 linux-image-5.8.0-55-generic-lpae 5.8.0-55.62~20.04.1 linux-image-5.8.0-55-lowlatency 5.8.0-55.62~20.04.1 linux-image-generic-64k-hwe-20.04 5.8.0.55.62~20.04.39 linux-image-generic-hwe-20.04 5.8.0.55.62~20.04.39 linux-image-generic-lpae-hwe-20.04 5.8.0.55.62~20.04.39 linux-image-lowlatency-hwe-20.04 5.8.0.55.62~20.04.39 linux-image-virtual-hwe-20.04 5.8.0.55.62~20.04.39
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-4984-1 CVE-2021-28038, CVE-2021-28660, CVE-2021-28688, CVE-2021-28950, CVE-2021-28952, CVE-2021-28964, CVE-2021-28971, CVE-2021-28972, CVE-2021-29647, CVE-2021-30002, CVE-2021-31916, CVE-2021-33033, CVE-2021-3483
Package Information: launchpad.net/ubuntu/+source/linux/5.8.0-55.62 launchpad.net/ubuntu/+source/linux-aws/5.8.0-1035.37 launchpad.net/ubuntu/+source/linux-azure/5.8.0-1033.35 launchpad.net/ubuntu/+source/linux-gcp/5.8.0-1032.34 launchpad.net/ubuntu/+source/linux-kvm/5.8.0-1028.30 launchpad.net/ubuntu/+source/linux-oracle/5.8.0-1031.32 launchpad.net/ubuntu/+source/linux-hwe-5.8/5.8.0-55.62~20.04.1