USN-4749-1: Linux kernel vulnerabilities

Releases

• Ubuntu 18.04 ESM
• Ubuntu 16.04 ESM
• Ubuntu 14.04 ESM

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-dell300x - Linux kernel for Dell 300x platforms
• 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

Bodong Zhao discovered a use-after-free in the Sun keyboard driver
implementation in the Linux kernel. A local attacker could use this to
cause a denial of service or possibly execute arbitrary code.
(CVE-2020-25669)

It was discovered that the jfs file system implementation in the Linux
kernel contained an out-of-bounds read vulnerability. A local attacker
could use this to possibly cause a denial of service (system crash).
(CVE-2020-27815)

Shisong Qin and Bodong Zhao discovered that Speakup screen reader driver in
the Linux kernel did not correctly handle setting line discipline in some
situations. A local attacker could use this to cause a denial of service
(system crash). (CVE-2020-27830, CVE-2020-28941)

It was discovered that the memory management subsystem in the Linux kernel
did not properly handle copy-on-write operations in some situations. A
local attacker could possibly use this to gain unintended write access to
read-only memory pages. (CVE-2020-29374)

Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event
processing backend in the Linux kernel did not properly limit the number of
events queued. An attacker in a guest VM could use this to cause a denial
of service in the host OS. (CVE-2020-29568)

Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the
Xen paravirt block backend in the Linux kernel, leading to a use-after-free
vulnerability. An attacker in a guest VM could use this to cause a denial
of service in the host OS. (CVE-2020-29569)

Jann Horn discovered that the tty subsystem of the Linux kernel did not use
consistent locking in some situations, leading to a read-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly expose sensitive information (kernel memory).
(CVE-2020-29660)

Jann Horn discovered a race condition in the tty subsystem of the Linux
kernel in the locking for the TIOCSPGRP ioctl(), 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-2020-29661)

Update instructions

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

Ubuntu 18.04

• linux-image-4.15.0-1012-dell300x - 4.15.0-1012.16
• linux-image-4.15.0-1065-oracle - 4.15.0-1065.73
• linux-image-4.15.0-1079-gke - 4.15.0-1079.84
• linux-image-4.15.0-1079-raspi2 - 4.15.0-1079.84
• linux-image-4.15.0-1085-kvm - 4.15.0-1085.87
• linux-image-4.15.0-1093-gcp - 4.15.0-1093.106
• linux-image-4.15.0-1094-aws - 4.15.0-1094.101
• linux-image-4.15.0-1096-snapdragon - 4.15.0-1096.105
• linux-image-4.15.0-1108-azure - 4.15.0-1108.120
• linux-image-4.15.0-136-generic - 4.15.0-136.140
• linux-image-4.15.0-136-generic-lpae - 4.15.0-136.140
• linux-image-4.15.0-136-lowlatency - 4.15.0-136.140
• linux-image-aws-lts-18.04 - 4.15.0.1094.97
• linux-image-azure-lts-18.04 - 4.15.0.1108.81
• linux-image-dell300x - 4.15.0.1012.14
• linux-image-gcp-lts-18.04 - 4.15.0.1093.111
• linux-image-generic - 4.15.0.136.123
• linux-image-generic-lpae - 4.15.0.136.123
• linux-image-gke - 4.15.0.1079.83
• linux-image-gke-4.15 - 4.15.0.1079.83
• linux-image-kvm - 4.15.0.1085.81
• linux-image-lowlatency - 4.15.0.136.123
• linux-image-oracle-lts-18.04 - 4.15.0.1065.75
• linux-image-raspi2 - 4.15.0.1079.76
• linux-image-snapdragon - 4.15.0.1096.99
• linux-image-virtual - 4.15.0.136.123

Ubuntu 16.04

• linux-image-4.15.0-1065-oracle - 4.15.0-1065.73~16.04.1
• linux-image-4.15.0-1093-gcp - 4.15.0-1093.106~16.04.1
• linux-image-4.15.0-1094-aws - 4.15.0-1094.101~16.04.1
• linux-image-4.15.0-1108-azure - 4.15.0-1108.120~16.04.1
• linux-image-4.15.0-136-generic - 4.15.0-136.140~16.04.1
• linux-image-4.15.0-136-generic-lpae - 4.15.0-136.140~16.04.1
• linux-image-4.15.0-136-lowlatency - 4.15.0-136.140~16.04.1
• linux-image-aws-hwe - 4.15.0.1094.87
• linux-image-azure - 4.15.0.1108.99
• linux-image-gcp - 4.15.0.1093.94
• linux-image-generic-hwe-16.04 - 4.15.0.136.132
• linux-image-generic-lpae-hwe-16.04 - 4.15.0.136.132
• linux-image-gke - 4.15.0.1093.94
• linux-image-lowlatency-hwe-16.04 - 4.15.0.136.132
• linux-image-oem - 4.15.0.136.132
• linux-image-oracle - 4.15.0.1065.53
• linux-image-virtual-hwe-16.04 - 4.15.0.136.132

Ubuntu 14.04

• linux-image-4.15.0-1108-azure - 4.15.0-1108.120~14.04.1
• linux-image-azure - 4.15.0.1108.81

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

• CVE-2020-27815
• CVE-2020-29660
• CVE-2020-27830
• CVE-2020-29568
• CVE-2020-29374
• CVE-2020-29569
• CVE-2020-29661
• CVE-2020-25669
• CVE-2020-28941

Related notices

• USN-4748-1: linux-image-4.4.0-1088-kvm, linux-image-kvm, linux-image-4.4.0-1122-aws, linux-image-powerpc-e500mc-lts-vivid, linux-image-powerpc64-smp, linux-image-virtual-lts-vivid, linux, linux-image-generic-lpae-lts-vivid, linux-image-4.4.0-1150-snapdragon, linux-image-powerpc-e500mc-lts-utopic, linux-image-powerpc-smp-lts-wily, linux-image-powerpc64-emb-lts-utopic, linux-image-virtual-lts-utopic, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc64-smp-lts-wily, linux-image-powerpc-e500mc-lts-wily, linux-image-4.4.0-203-powerpc64-emb, linux-image-powerpc64-emb-lts-xenial, linux-raspi2, linux-image-powerpc-smp-lts-vivid, linux-image-lowlatency-lts-xenial, linux-image-lowlatency-lts-wily, linux-image-powerpc-e500mc, linux-snapdragon, linux-image-lowlatency, linux-image-snapdragon, linux-image-powerpc-smp, linux-lts-xenial, linux-image-generic-lpae, linux-image-powerpc64-smp-lts-vivid, linux-image-generic-lts-vivid, linux-image-generic-lpae-lts-utopic, linux-image-virtual-lts-xenial, linux-image-powerpc-e500mc-lts-xenial, linux-image-4.4.0-1086-aws, linux-image-4.4.0-203-generic, linux-image-4.4.0-203-powerpc64-smp, linux-image-generic-lts-utopic, linux-image-generic-lpae-lts-wily, linux-image-4.4.0-203-powerpc-e500mc, linux-image-4.4.0-203-lowlatency, linux-image-lowlatency-lts-utopic, linux-image-4.4.0-203-powerpc-smp, linux-image-generic, linux-image-lowlatency-lts-vivid, linux-image-powerpc64-emb-lts-wily, linux-image-raspi2, linux-image-powerpc-smp-lts-utopic, linux-image-4.4.0-203-generic-lpae, linux-image-4.4.0-1146-raspi2, linux-image-virtual, linux-image-aws, linux-image-powerpc-smp-lts-xenial, linux-kvm, linux-aws, linux-image-generic-lts-wily, linux-image-powerpc64-emb-lts-vivid, linux-image-powerpc64-smp-lts-utopic, linux-image-powerpc64-emb, linux-image-generic-lpae-lts-xenial, linux-image-generic-lts-xenial, linux-image-virtual-lts-wily
• USN-4750-1: linux-image-kvm, linux-image-snapdragon-hwe-18.04, linux, linux-gke-5.4, linux-image-lowlatency-hwe-18.04-edge, linux-oracle-5.4, linux-azure-5.4, linux-image-lowlatency-hwe-18.04, linux-image-oracle-edge, linux-image-5.4.0-1010-gkeop, linux-image-gcp-edge, linux-image-generic-hwe-18.04, linux-image-raspi, linux-oracle, linux-hwe-5.4, linux-gcp-5.4, linux-raspi, linux-gkeop-5.4, linux-image-raspi2-hwe-18.04, linux-image-azure-edge, linux-image-virtual-hwe-18.04-edge, linux-gkeop, linux-azure, linux-image-generic-hwe-18.04-edge, linux-image-lowlatency, linux-image-virtual-hwe-18.04, linux-image-generic-lpae, linux-image-generic-lpae-hwe-18.04-edge, linux-image-5.4.0-1037-gcp, linux-image-5.4.0-1036-gke, linux-image-5.4.0-1033-kvm, linux-aws-5.4, linux-image-oem-osp1, linux-image-azure, linux-raspi-5.4, linux-image-gkeop, linux-image-5.4.0-66-generic, linux-image-aws-edge, linux-gcp, linux-image-snapdragon-hwe-18.04-edge, linux-image-generic, linux-image-raspi-hwe-18.04-edge, linux-image-oem, linux-image-raspi2, linux-image-5.4.0-1038-aws, linux-image-oracle, linux-image-gcp, linux-image-raspi-hwe-18.04, linux-image-raspi2-hwe-18.04-edge, linux-image-gkeop-5.4, linux-image-generic-lpae-hwe-18.04, linux-image-gke-5.4, linux-image-virtual, linux-image-aws, linux-image-5.4.0-66-generic-lpae, linux-kvm, linux-aws, linux-image-5.4.0-1029-raspi, linux-image-5.4.0-66-lowlatency, linux-image-5.4.0-1040-azure, linux-image-5.4.0-1038-oracle
• USN-4751-1: linux-hwe-5.8, linux-image-kvm, linux-image-5.8.0-1023-gcp, linux-image-5.8.0-44-generic-64k, linux-image-gke, linux, linux-image-generic-lpae-hwe-20.04, linux-image-generic-hwe-20.04, linux-image-generic-lpae-hwe-20.04-edge, linux-image-virtual-hwe-20.04, linux-image-oem-20.04, linux-image-generic-hwe-20.04-edge, linux-image-raspi, linux-raspi, linux-image-5.8.0-1016-raspi-nolpae, linux-azure, linux-image-lowlatency, linux-image-generic-lpae, linux-image-5.8.0-44-generic-lpae, linux-image-raspi-nolpae, linux-image-azure, linux-image-virtual-hwe-20.04-edge, linux-image-5.8.0-44-generic, linux-image-generic-64k-hwe-20.04-edge, linux-image-lowlatency-hwe-20.04-edge, linux-gcp, linux-image-generic, linux-image-5.8.0-44-lowlatency, linux-image-generic-64k-hwe-20.04, linux-image-5.8.0-1019-kvm, linux-image-gcp, linux-image-oracle, linux-image-virtual, linux-image-5.8.0-1021-oracle, linux-image-aws, linux-kvm, linux-image-lowlatency-hwe-20.04, linux-aws, linux-image-5.8.0-1024-aws, linux-image-5.8.0-1023-azure, linux-image-5.8.0-1016-raspi, linux-oracle, linux-image-generic-64k
• USN-4752-1: linux-image-5.6.0-1048-oem, linux-image-oem-20.04, linux-oem-5.6
• USN-5130-1: linux-signed-image-generic-lts-quantal, linux-hwe-virtual-trusty, linux-cloud-tools-lowlatency, linux-lowlatency-pae, linux-tools-generic-lpae, linux-generic-lts-saucy, linux-image-omap, linux-tools-powerpc-e500, linux-signed-image-generic, linux-headers-powerpc-smp, linux-generic-lpae-lts-saucy-eol-upgrade, linux-generic, linux-headers-3.13.0-188-lowlatency, linux-headers-server, linux-image-generic-lpae, linux-generic-lts-raring, linux-image-generic-lts-quantal, linux-powerpc-e500mc, linux-tools-lts-quantal, linux-tools-3.13.0-188-powerpc-e500, linux-modules-3.13.0-188-generic-lpae, linux-image-3.13.0-188-lowlatency, linux-signed-generic-lts-raring, linux-signed-image-generic-lts-trusty, linux-tools-lowlatency, linux-headers-3.13.0-188-powerpc64-emb, linux-image-unsigned-3.13.0-188-generic, linux-powerpc64-emb, linux-generic-lts-raring-eol-upgrade, linux-tools-lts-raring, linux-image-3.13.0-188-powerpc64-smp, linux-tools-generic-lts-trusty, linux-image-virtual, linux-tools-3.13.0-188-powerpc-e500mc, linux-signed-generic-lts-raring-eol-upgrade, linux-headers-generic-lts-saucy, linux-generic-lts-saucy-eol-upgrade, linux-headers-virtual, linux-headers-highbank, linux-hwe-generic-trusty, linux-server, linux-headers-powerpc64-emb, linux-tools-powerpc64-emb, linux-headers-powerpc-e500, linux-tools-virtual, linux-headers-lowlatency, linux-signed-generic, linux-buildinfo-3.13.0-188-powerpc-e500, linux-tools-generic-lpae-lts-saucy, linux-virtual, linux, linux-tools-powerpc-smp, linux-image-generic-lts-saucy, linux-modules-3.13.0-188-generic, linux-headers-3.13.0-188-powerpc-smp, linux-source-3.13.0, linux-image-generic-lts-raring, linux-image-generic-lpae-lts-trusty, linux-image-extra-virtual, linux-buildinfo-3.13.0-188-powerpc-smp, linux-headers-generic-lpae, linux-modules-3.13.0-188-lowlatency, linux-modules-3.13.0-188-powerpc-e500, linux-modules-3.13.0-188-powerpc-smp, linux-powerpc64-smp, linux-headers-3.13.0-188-generic, linux-headers-powerpc-e500mc, linux-image-3.13.0-188-generic, linux-buildinfo-3.13.0-188-generic-lpae, linux-headers-3.13.0-188-powerpc64-smp, linux-generic-lts-quantal, linux-powerpc-smp, linux-tools-generic-lts-saucy, linux-image-generic-pae, linux-libc-dev, linux-signed-generic-lts-saucy, linux-signed-generic-lts-trusty, linux-headers-generic-lts-trusty, linux-signed-generic-lts-quantal, linux-tools-3.13.0-188-generic, linux-cloud-tools-virtual, linux-generic-lpae, linux-headers-3.13.0-188-generic-lpae, linux-generic-pae, linux-buildinfo-3.13.0-188-powerpc64-smp, linux-cloud-tools-generic, linux-image-generic-lts-trusty, linux-powerpc-e500, linux-image-3.13.0-188-powerpc-e500mc, linux-image-powerpc64-smp, linux-doc, linux-cloud-tools-common, linux-generic-lts-quantal-eol-upgrade, linux-tools-lts-saucy, linux-omap, linux-tools-3.13.0-188-lowlatency, linux-tools-powerpc64-smp, linux-headers-generic-pae, linux-image-powerpc-e500mc, linux-source, linux-image-hwe-generic-trusty, linux-buildinfo-3.13.0-188-generic, linux-image-lowlatency-pae, linux-tools-common, linux-buildinfo-3.13.0-188-lowlatency, linux-tools-3.13.0-188-powerpc-smp, linux-image-generic-lpae-lts-saucy, linux-signed-image-generic-lts-saucy, linux-modules-3.13.0-188-powerpc64-emb, linux-signed-generic-lts-saucy-eol-upgrade, linux-modules-3.13.0-188-powerpc64-smp, linux-generic-lpae-lts-trusty, linux-generic-lpae-lts-saucy, linux-image-powerpc64-emb, linux-highbank, linux-image-3.13.0-188-powerpc-e500, linux-signed-generic-lts-quantal-eol-upgrade, linux-headers-omap, linux-tools-3.13.0-188, linux-tools-3.13.0-188-powerpc64-smp, linux-image-unsigned-3.13.0-188-lowlatency, hv-kvp-daemon-init, linux-tools-generic, linux-tools-lts-trusty, linux-headers-generic, linux-image-3.13.0-188-powerpc-smp, linux-headers-generic-lts-raring, linux-tools-generic-lpae-lts-trusty, linux-image-highbank, linux-buildinfo-3.13.0-188-powerpc-e500mc, linux-generic-lts-trusty, linux-headers-lowlatency-pae, linux-crashdump, linux-headers-3.13.0-188-powerpc-e500, linux-tools-3.13.0-188-powerpc64-emb, linux-image-lowlatency, linux-headers-generic-lts-quantal, linux-image-powerpc-smp, linux-modules-3.13.0-188-powerpc-e500mc, linux-cloud-tools-3.13.0-188-generic, linux-modules-extra-3.13.0-188-generic, linux-image-powerpc-e500, linux-tools-3.13.0-188-generic-lpae, linux-image-3.13.0-188-powerpc64-emb, linux-headers-3.13.0-188-powerpc-e500mc, linux-cloud-tools-3.13.0-188-lowlatency, linux-signed-image-generic-lts-raring, linux-headers-3.13.0-188, linux-cloud-tools-3.13.0-188, linux-image-generic, linux-tools-powerpc-e500mc, linux-image-server, linux-headers-generic-lpae-lts-saucy, linux-image-3.13.0-188-generic-lpae, linux-headers-powerpc64-smp, linux-image-hwe-virtual-trusty, linux-buildinfo-3.13.0-188-powerpc64-emb, linux-lowlatency, linux-headers-generic-lpae-lts-trusty
• LSN-0082-1: gkeop, gkeop-5.4, generic-4.4, lowlatency-5.4, generic-4.15, lowlatency-4.4, lowlatency-4.15, gke-4.15, oem, gcp, gke, gke-5.4, generic-5.4
• USN-4912-1: linux-image-5.6.0-1053-oem, linux-image-oem-20.04, linux-oem-5.6
• USN-4876-1: linux-image-kvm, linux-image-powerpc-e500mc-lts-vivid, linux-image-virtual-lts-vivid, linux-image-powerpc64-smp, linux-image-4.4.0-204-generic, linux, linux-image-generic-lpae-lts-xenial, linux-image-generic-lpae-lts-vivid, linux-image-powerpc-e500mc-lts-utopic, linux-image-4.4.0-204-generic-lpae, linux-image-powerpc-smp-lts-wily, linux-image-4.4.0-204-powerpc-e500mc, linux-image-4.4.0-1123-aws, linux-image-powerpc64-emb-lts-utopic, linux-image-virtual-lts-utopic, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc64-smp-lts-wily, linux-image-powerpc-e500mc-lts-wily, linux-image-powerpc64-emb-lts-xenial, linux-raspi2, linux-image-powerpc-smp-lts-vivid, linux-image-lowlatency-lts-xenial, linux-image-lowlatency-lts-wily, linux-image-powerpc-e500mc, linux-snapdragon, linux-image-lowlatency, linux-image-4.4.0-204-powerpc-smp, linux-image-snapdragon, linux-image-powerpc-smp, linux-lts-xenial, linux-image-generic-lpae, linux-image-4.4.0-1087-aws, linux-image-powerpc64-smp-lts-vivid, linux-image-generic-lts-vivid, linux-image-generic-lpae-lts-utopic, linux-image-virtual-lts-xenial, linux-image-powerpc-e500mc-lts-xenial, linux-image-4.4.0-1089-kvm, linux-image-generic-lts-utopic, linux-image-generic-lpae-lts-wily, linux-image-lowlatency-lts-utopic, linux-image-generic, linux-image-lowlatency-lts-vivid, linux-image-powerpc64-emb-lts-wily, linux-image-raspi2, linux-image-powerpc-smp-lts-utopic, linux-image-4.4.0-204-powerpc64-smp, linux-image-virtual, linux-image-4.4.0-1151-snapdragon, linux-image-aws, linux-image-powerpc-smp-lts-xenial, linux-kvm, linux-aws, linux-image-generic-lts-wily, linux-image-powerpc64-emb-lts-vivid, linux-image-powerpc64-smp-lts-utopic, linux-image-powerpc64-emb, linux-image-4.4.0-204-powerpc64-emb, linux-image-generic-lts-xenial, linux-image-4.4.0-204-lowlatency, linux-image-4.4.0-1147-raspi2, linux-image-virtual-lts-wily
• USN-4708-1: linux-image-powerpc-e500mc-lts-vivid, linux-image-virtual-lts-vivid, linux-image-powerpc64-smp, linux, linux-image-generic-lpae-lts-vivid, linux-image-powerpc-e500mc-lts-utopic, linux-image-powerpc-smp-lts-wily, linux-image-powerpc64-emb-lts-utopic, linux-image-virtual-lts-utopic, linux-image-4.4.0-201-powerpc-smp, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc64-smp-lts-wily, linux-image-powerpc-e500mc-lts-wily, linux-image-powerpc64-emb-lts-xenial, linux-image-powerpc-smp-lts-vivid, linux-image-lowlatency-lts-xenial, linux-image-lowlatency-lts-wily, linux-image-powerpc-e500mc, linux-image-lowlatency, linux-image-4.4.0-201-powerpc64-emb, linux-image-powerpc-smp, linux-lts-xenial, linux-image-generic-lpae, linux-image-powerpc64-smp-lts-vivid, linux-image-generic-lts-vivid, linux-image-generic-lpae-lts-utopic, linux-image-virtual-lts-xenial, linux-image-powerpc-e500mc-lts-xenial, linux-image-generic-lts-utopic, linux-image-generic-lpae-lts-wily, linux-image-4.4.0-201-powerpc-e500mc, linux-image-4.4.0-201-powerpc64-smp, linux-image-lowlatency-lts-utopic, linux-image-4.4.0-201-generic-lpae, linux-image-generic, linux-image-lowlatency-lts-vivid, linux-image-4.4.0-201-lowlatency, linux-image-powerpc64-emb-lts-wily, linux-image-4.4.0-201-generic, linux-image-powerpc-smp-lts-utopic, linux-image-virtual, linux-image-powerpc-smp-lts-xenial, linux-image-generic-lts-wily, linux-image-powerpc64-emb-lts-vivid, linux-image-powerpc64-smp-lts-utopic, linux-image-powerpc64-emb, linux-image-generic-lpae-lts-xenial, linux-image-generic-lts-xenial, linux-image-virtual-lts-wily
• USN-4709-1: linux-image-kvm, linux-image-4.4.0-1149-snapdragon, linux-image-4.4.0-1087-kvm, linux-image-4.4.0-1085-aws, linux-image-4.4.0-1145-raspi2, linux-image-aws, linux-kvm, linux-snapdragon, linux-aws, linux-image-snapdragon, linux-image-4.4.0-1121-aws, linux-image-raspi2, linux-raspi2