USN-4680-1: Linux kernel vulnerabilities

06 January 2021

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-aws-hwe - Linux kernel for Amazon Web Services (AWS-HWE) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-azure-4.15 - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-4.15 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke-4.15 - Linux kernel for Google Container Engine (GKE) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • 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

Details

It was discovered that debugfs in the Linux kernel as used by blktrace
contained a use-after-free in some situations. A privileged local attacker
could possibly use this to cause a denial of service (system crash).
(CVE-2019-19770)

It was discovered that a race condition existed in the binder IPC
implementation in the Linux kernel, 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-2020-0423)

Daniele Antonioli, Nils Ole Tippenhauer, and Kasper Rasmussen discovered
that legacy pairing and secure-connections pairing authentication in the
Bluetooth protocol could allow an unauthenticated user to complete
authentication without pairing credentials via adjacent access. A
physically proximate attacker could use this to impersonate a previously
paired Bluetooth device. (CVE-2020-10135)

It was discovered that the console keyboard driver in the Linux kernel
contained a race condition. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2020-25656)

Minh Yuan discovered that the tty driver in the Linux kernel contained race
conditions when handling fonts. A local attacker could possibly use this to
expose sensitive information (kernel memory). (CVE-2020-25668)

Keyu Man discovered that the ICMP global rate limiter in the Linux kernel
could be used to assist in scanning open UDP ports. A remote attacker could
use to facilitate attacks on UDP based services that depend on source port
randomization. (CVE-2020-25705)

Jinoh Kang discovered that the Xen event channel infrastructure in the
Linux kernel contained a race condition. An attacker in guest could
possibly use this to cause a denial of service (dom0 crash).
(CVE-2020-27675)

Daniel Axtens discovered that PowerPC RTAS implementation in the Linux
kernel did not properly restrict memory accesses in some situations. A
privileged local attacker could use this to arbitrarily modify kernel
memory, potentially bypassing kernel lockdown restrictions.
(CVE-2020-27777)

Minh Yuan discovered that the framebuffer console driver in the Linux
kernel did not properly handle fonts in some conditions. A local attacker
could use this to cause a denial of service (system crash) or possibly
expose sensitive information (kernel memory). (CVE-2020-28974)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 18.04
Ubuntu 16.04
Ubuntu 14.04

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.

Related notices

  • USN-4658-1: linux-image-snapdragon-hwe-18.04, linux-image-5.4.0-56-generic, linux-oracle, linux, linux-image-lowlatency-hwe-18.04-edge, linux-gcp-5.4, linux-image-raspi, linux-image-lowlatency-hwe-18.04, linux-image-aws-edge, linux-image-5.4.0-1030-oracle, linux-image-5.4.0-1028-kvm, linux-image-kvm, linux-image-virtual-hwe-18.04, linux-image-virtual, linux-image-generic, linux-aws, linux-image-generic-lpae-hwe-18.04-edge, linux-image-oem, linux-image-5.4.0-1030-gcp, linux-image-generic-hwe-20.04, linux-image-generic-lpae-hwe-20.04, linux-image-generic-lpae-hwe-18.04, linux-image-5.4.0-56-lowlatency, linux-hwe-5.4, linux-azure, linux-image-azure-edge, linux-image-raspi2, linux-image-5.4.0-1032-azure, linux-image-5.4.0-1023-raspi, linux-image-snapdragon-hwe-18.04-edge, linux-image-gcp, linux-image-5.4.0-1030-aws, linux-image-aws, linux-image-raspi2-hwe-18.04-edge, linux-image-gcp-edge, linux-image-raspi2-hwe-18.04, linux-kvm, linux-gcp, linux-image-generic-hwe-18.04-edge, linux-image-gke, linux-image-lowlatency, linux-image-oracle, linux-image-raspi-hwe-18.04-edge, linux-image-virtual-hwe-18.04-edge, linux-aws-5.4, linux-image-raspi-hwe-18.04, linux-image-5.4.0-56-generic-lpae, linux-image-lowlatency-hwe-20.04, linux-image-oem-osp1, linux-image-virtual-hwe-20.04, linux-raspi, linux-image-generic-lpae, linux-image-oracle-edge, linux-raspi-5.4, linux-image-azure, linux-image-generic-hwe-18.04, linux-oracle-5.4, linux-azure-5.4
  • USN-4681-1: linux-image-4.4.0-1083-aws, linux-image-lowlatency-lts-wily, linux, linux-image-powerpc-smp-lts-xenial, linux-image-4.4.0-1147-snapdragon, linux-image-powerpc64-smp, linux-image-generic-lts-vivid, linux-image-snapdragon, linux-image-powerpc-smp, linux-image-powerpc64-smp-lts-wily, linux-image-4.4.0-1119-aws, linux-image-virtual-lts-utopic, linux-image-4.4.0-1143-raspi2, linux-image-4.4.0-198-powerpc-smp, linux-image-generic-lts-utopic, linux-image-kvm, linux-image-virtual-lts-vivid, linux-image-powerpc64-emb-lts-utopic, linux-image-virtual, linux-image-generic, linux-aws, linux-image-4.4.0-198-powerpc64-emb, linux-image-4.4.0-198-powerpc64-smp, linux-image-generic-lts-xenial, linux-image-generic-lpae-lts-utopic, linux-image-powerpc-e500mc-lts-vivid, linux-image-powerpc-smp-lts-vivid, linux-image-lowlatency-lts-xenial, linux-image-powerpc-e500mc-lts-xenial, linux-image-raspi2, linux-image-generic-lpae-lts-xenial, linux-image-4.4.0-198-generic-lpae, linux-raspi2, linux-image-powerpc-e500mc, linux-image-4.4.0-1085-kvm, linux-image-virtual-lts-xenial, linux-image-aws, linux-snapdragon, linux-image-4.4.0-198-lowlatency, linux-image-powerpc64-smp-lts-utopic, linux-image-virtual-lts-wily, linux-image-powerpc64-smp-lts-xenial, linux-kvm, linux-image-powerpc64-emb, linux-lts-xenial, linux-image-powerpc64-smp-lts-vivid, linux-image-lowlatency, linux-image-powerpc-smp-lts-wily, linux-image-lowlatency-lts-vivid, linux-image-powerpc64-emb-lts-wily, linux-image-powerpc-smp-lts-utopic, linux-image-powerpc64-emb-lts-xenial, linux-image-generic-lpae-lts-vivid, linux-image-4.4.0-198-generic, linux-image-generic-lpae, linux-image-generic-lts-wily, linux-image-powerpc-e500mc-lts-utopic, linux-image-generic-lpae-lts-wily, linux-image-lowlatency-lts-utopic, linux-image-powerpc64-emb-lts-vivid, linux-image-4.4.0-198-powerpc-e500mc, linux-image-powerpc-e500mc-lts-wily
  • USN-4912-1: linux-image-5.6.0-1053-oem, linux-oem-5.6, linux-image-oem-20.04
  • USN-4751-1: linux-image-5.8.0-1016-raspi-nolpae, linux-oracle, linux, linux-image-generic-lpae-hwe-20.04-edge, linux-image-raspi, linux-image-lowlatency-hwe-20.04-edge, linux-image-5.8.0-1023-azure, linux-image-generic-hwe-20.04-edge, linux-image-kvm, linux-image-5.8.0-44-generic-64k, linux-image-virtual, linux-image-generic, linux-aws, linux-image-generic-64k-hwe-20.04, linux-image-generic-hwe-20.04, linux-image-generic-lpae-hwe-20.04, linux-azure, linux-hwe-5.8, linux-image-5.8.0-1024-aws, linux-image-gcp, linux-image-generic-64k, linux-image-5.8.0-1021-oracle, linux-image-aws, linux-kvm, linux-gcp, linux-image-gke, linux-image-oracle, linux-image-lowlatency, linux-image-5.8.0-1016-raspi, linux-image-5.8.0-44-lowlatency, linux-image-virtual-hwe-20.04, linux-image-lowlatency-hwe-20.04, linux-image-5.8.0-44-generic, linux-raspi, linux-image-5.8.0-44-generic-lpae, linux-image-generic-64k-hwe-20.04-edge, linux-image-generic-lpae, linux-image-5.8.0-1019-kvm, linux-image-oem-20.04, linux-image-5.8.0-1023-gcp, linux-image-virtual-hwe-20.04-edge, linux-image-raspi-nolpae, linux-image-azure
  • USN-4657-1: linux-image-4.4.0-1082-aws, linux-image-lowlatency-lts-wily, linux, linux-image-powerpc-smp-lts-xenial, linux-image-powerpc64-smp, linux-image-generic-lts-vivid, linux-image-snapdragon, linux-image-powerpc-smp, linux-image-powerpc64-smp-lts-wily, linux-image-virtual-lts-utopic, linux-image-generic-lts-utopic, linux-image-kvm, linux-image-virtual-lts-vivid, linux-image-4.4.0-197-powerpc64-smp, linux-image-powerpc64-emb-lts-utopic, linux-image-virtual, linux-image-generic, linux-aws, linux-image-generic-lts-xenial, linux-image-generic-lpae-lts-utopic, linux-image-powerpc-e500mc-lts-vivid, linux-image-powerpc-smp-lts-vivid, linux-image-lowlatency-lts-xenial, linux-image-4.4.0-1142-raspi2, linux-image-4.4.0-1146-snapdragon, linux-image-powerpc-e500mc-lts-xenial, linux-image-raspi2, linux-image-generic-lpae-lts-xenial, linux-raspi2, linux-image-powerpc-e500mc, linux-image-virtual-lts-xenial, linux-snapdragon, linux-image-aws, linux-image-4.4.0-197-powerpc-e500mc, linux-image-4.4.0-1118-aws, linux-image-powerpc64-smp-lts-utopic, linux-image-virtual-lts-wily, linux-image-powerpc64-smp-lts-xenial, linux-image-4.4.0-197-lowlatency, linux-image-powerpc64-emb, linux-kvm, linux-image-powerpc64-smp-lts-vivid, linux-image-4.4.0-1084-kvm, linux-image-lowlatency, linux-image-powerpc-smp-lts-wily, linux-lts-xenial, linux-image-lowlatency-lts-vivid, linux-image-powerpc64-emb-lts-wily, linux-image-powerpc-smp-lts-utopic, linux-image-powerpc64-emb-lts-xenial, linux-image-generic-lpae-lts-vivid, linux-image-4.4.0-197-generic-lpae, linux-image-generic-lpae, linux-image-generic-lts-wily, linux-image-powerpc-e500mc-lts-utopic, linux-image-generic-lpae-lts-wily, linux-image-lowlatency-lts-utopic, linux-image-4.4.0-197-powerpc-smp, linux-image-powerpc64-emb-lts-vivid, linux-image-4.4.0-197-generic, linux-image-4.4.0-197-powerpc64-emb, linux-image-powerpc-e500mc-lts-wily
  • USN-4679-1: linux-image-snapdragon-hwe-18.04, linux-image-5.4.0-1033-gke, linux-image-5.4.0-59-lowlatency, linux-oracle, linux, linux-image-5.4.0-59-generic, linux-image-lowlatency-hwe-18.04-edge, linux-gcp-5.4, linux-image-raspi, linux-image-lowlatency-hwe-18.04, linux-image-aws-edge, linux-image-kvm, linux-image-virtual-hwe-18.04, linux-image-virtual, linux-image-generic, linux-aws, linux-image-generic-lpae-hwe-18.04-edge, linux-image-oem, linux-image-5.4.0-1026-raspi, linux-image-generic-hwe-20.04, linux-image-generic-lpae-hwe-20.04, linux-image-generic-lpae-hwe-18.04, linux-image-5.4.0-1035-azure, linux-hwe-5.4, linux-oracle-5.4, linux-azure, linux-image-azure-edge, linux-image-raspi2, linux-image-gke-5.4, linux-image-snapdragon-hwe-18.04-edge, linux-image-gcp, linux-image-5.4.0-1034-aws, linux-gke-5.4, linux-image-aws, linux-image-raspi2-hwe-18.04-edge, linux-image-gcp-edge, linux-image-raspi2-hwe-18.04, linux-kvm, linux-gcp, linux-image-generic-hwe-18.04-edge, linux-image-oracle, linux-image-lowlatency, linux-image-raspi-hwe-18.04-edge, linux-image-virtual-hwe-18.04-edge, linux-aws-5.4, linux-image-5.4.0-1031-kvm, linux-image-raspi-hwe-18.04, linux-image-lowlatency-hwe-20.04, linux-image-oem-osp1, linux-image-virtual-hwe-20.04, linux-raspi, linux-image-generic-lpae, linux-image-5.4.0-1034-oracle, linux-image-oracle-edge, linux-image-5.4.0-59-generic-lpae, linux-raspi-5.4, linux-image-azure, linux-image-generic-hwe-18.04, linux-image-5.4.0-1033-gcp, linux-azure-5.4
  • USN-4659-1: linux-image-5.8.0-1011-oracle, linux-image-5.8.0-1014-aws, linux-image-5.8.0-1012-gcp, linux-oracle, linux, linux-image-generic-lpae-hwe-20.04-edge, linux-image-raspi, linux-image-lowlatency-hwe-20.04-edge, linux-image-generic-hwe-20.04-edge, linux-image-kvm, linux-image-virtual, linux-image-5.8.0-31-generic-lpae, linux-aws, linux-image-generic, linux-image-5.8.0-1008-raspi-nolpae, linux-image-generic-64k-hwe-20.04, linux-image-generic-hwe-20.04, linux-image-generic-lpae-hwe-20.04, linux-azure, linux-image-5.8.0-1008-raspi, linux-image-gcp, linux-image-generic-64k, linux-image-aws, linux-kvm, linux-gcp, linux-image-gke, linux-image-oracle, linux-image-lowlatency, linux-image-virtual-hwe-20.04, linux-image-lowlatency-hwe-20.04, linux-image-5.8.0-1011-kvm, linux-raspi, linux-image-generic-64k-hwe-20.04-edge, linux-image-generic-lpae, linux-image-oem-20.04, linux-image-5.8.0-31-generic-64k, linux-image-5.8.0-31-generic, linux-image-virtual-hwe-20.04-edge, linux-image-raspi-nolpae, linux-image-5.8.0-31-lowlatency, linux-image-5.8.0-1013-azure, linux-image-azure
  • USN-4752-1: linux-oem-5.6, linux-image-oem-20.04, linux-image-5.6.0-1048-oem
  • USN-4683-1: linux-oem-5.6, linux-image-5.6.0-1039-oem, linux-image-oem-20.04
  • USN-4708-1: linux-image-4.4.0-201-powerpc64-emb, linux-image-lowlatency-lts-wily, linux, linux-image-4.4.0-201-generic-lpae, linux-image-powerpc-smp-lts-xenial, linux-image-powerpc64-smp, linux-image-generic-lts-vivid, linux-image-powerpc-smp, linux-image-powerpc64-smp-lts-wily, linux-image-virtual-lts-utopic, linux-image-generic-lts-utopic, linux-image-4.4.0-201-generic, linux-image-virtual-lts-vivid, linux-image-powerpc64-emb-lts-utopic, linux-image-virtual, linux-image-generic, linux-image-generic-lts-xenial, linux-image-generic-lpae-lts-utopic, linux-image-powerpc-e500mc-lts-vivid, linux-image-powerpc-smp-lts-vivid, linux-image-lowlatency-lts-xenial, linux-image-powerpc-e500mc-lts-xenial, linux-image-generic-lpae-lts-xenial, linux-image-powerpc-e500mc, linux-image-virtual-lts-xenial, linux-image-4.4.0-201-lowlatency, linux-image-powerpc64-smp-lts-utopic, linux-image-virtual-lts-wily, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc64-emb, linux-lts-xenial, linux-image-powerpc64-smp-lts-vivid, linux-image-4.4.0-201-powerpc-e500mc, linux-image-lowlatency, linux-image-powerpc-smp-lts-wily, linux-image-lowlatency-lts-vivid, linux-image-powerpc64-emb-lts-wily, linux-image-powerpc-smp-lts-utopic, linux-image-powerpc64-emb-lts-xenial, linux-image-4.4.0-201-powerpc-smp, linux-image-generic-lpae-lts-vivid, linux-image-4.4.0-201-powerpc64-smp, linux-image-generic-lpae, linux-image-generic-lts-wily, linux-image-powerpc-e500mc-lts-utopic, linux-image-generic-lpae-lts-wily, linux-image-lowlatency-lts-utopic, linux-image-powerpc64-emb-lts-vivid, linux-image-powerpc-e500mc-lts-wily