==========================================================================
Ubuntu Security Notice USN-4883-1
March 20, 2021

linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp,
linux-gcp-4.15, linux-hwe, linux-kvm, linux-raspi2, linux-snapdragon
vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM

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-4.15: Linux kernel for Microsoft Azure Cloud systems
- linux-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems
- linux-kvm: Linux kernel for cloud environments
- linux-raspi2: Linux kernel for Raspberry Pi (V8) systems
- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors
- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems
- linux-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-hwe: Linux hardware enablement (HWE) kernel

Details:

Adam Nichols discovered that heap overflows existed in the iSCSI subsystem
in the Linux kernel. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2021-27365)

Adam Nichols discovered that the iSCSI subsystem in the Linux kernel did
not properly restrict access to iSCSI transport handles. A local attacker
could use this to cause a denial of service or expose sensitive information
(kernel pointer addresses). (CVE-2021-27363)

Adam Nichols discovered that an out-of-bounds read existed in the iSCSI
subsystem in the Linux kernel. A local attacker could use this to cause a
denial of service (system crash) or expose sensitive information (kernel
memory). (CVE-2021-27364)

Update instructions:

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

Ubuntu 18.04 LTS:
  linux-image-4.15.0-1081-raspi2  4.15.0-1081.86
  linux-image-4.15.0-1087-kvm     4.15.0-1087.89
  linux-image-4.15.0-1095-gcp     4.15.0-1095.108
  linux-image-4.15.0-1096-aws     4.15.0-1096.103
  linux-image-4.15.0-1098-snapdragon  4.15.0-1098.107
  linux-image-4.15.0-1110-azure   4.15.0-1110.122
  linux-image-4.15.0-139-generic  4.15.0-139.143
  linux-image-4.15.0-139-generic-lpae  4.15.0-139.143
  linux-image-4.15.0-139-lowlatency  4.15.0-139.143
  linux-image-aws-lts-18.04       4.15.0.1096.99
  linux-image-azure-lts-18.04     4.15.0.1110.83
  linux-image-gcp-lts-18.04       4.15.0.1095.113
  linux-image-generic             4.15.0.139.126
  linux-image-generic-lpae        4.15.0.139.126
  linux-image-kvm                 4.15.0.1087.83
  linux-image-lowlatency          4.15.0.139.126
  linux-image-powerpc-e500mc      4.15.0.139.126
  linux-image-powerpc-smp         4.15.0.139.126
  linux-image-powerpc64-emb       4.15.0.139.126
  linux-image-powerpc64-smp       4.15.0.139.126
  linux-image-raspi2              4.15.0.1081.78
  linux-image-snapdragon          4.15.0.1098.101
  linux-image-virtual             4.15.0.139.126

Ubuntu 16.04 LTS:
  linux-image-4.15.0-1095-gcp     4.15.0-1095.108~16.04.1
  linux-image-4.15.0-1096-aws     4.15.0-1096.103~16.04.1
  linux-image-4.15.0-1110-azure   4.15.0-1110.122~16.04.1
  linux-image-4.15.0-139-generic  4.15.0-139.143~16.04.1
  linux-image-4.15.0-139-generic-lpae  4.15.0-139.143~16.04.1
  linux-image-4.15.0-139-lowlatency  4.15.0-139.143~16.04.1
  linux-image-4.4.0-1090-kvm      4.4.0-1090.99
  linux-image-4.4.0-1124-aws      4.4.0-1124.138
  linux-image-4.4.0-1152-snapdragon  4.4.0-1152.162
  linux-image-4.4.0-206-generic   4.4.0-206.238
  linux-image-4.4.0-206-generic-lpae  4.4.0-206.238
  linux-image-4.4.0-206-lowlatency  4.4.0-206.238
  linux-image-4.4.0-206-powerpc-e500mc  4.4.0-206.238
  linux-image-4.4.0-206-powerpc-smp  4.4.0-206.238
  linux-image-4.4.0-206-powerpc64-emb  4.4.0-206.238
  linux-image-4.4.0-206-powerpc64-smp  4.4.0-206.238
  linux-image-aws                 4.4.0.1124.129
  linux-image-aws-hwe             4.15.0.1096.89
  linux-image-azure               4.15.0.1110.101
  linux-image-azure-edge          4.15.0.1110.101
  linux-image-gcp                 4.15.0.1095.96
  linux-image-generic             4.4.0.206.212
  linux-image-generic-hwe-16.04   4.15.0.139.134
  linux-image-generic-lpae        4.4.0.206.212
  linux-image-generic-lpae-hwe-16.04  4.15.0.139.134
  linux-image-gke                 4.15.0.1095.96
  linux-image-kvm                 4.4.0.1090.88
  linux-image-lowlatency          4.4.0.206.212
  linux-image-lowlatency-hwe-16.04  4.15.0.139.134
  linux-image-oem                 4.15.0.139.134
  linux-image-powerpc-e500mc      4.4.0.206.212
  linux-image-powerpc-smp         4.4.0.206.212
  linux-image-powerpc64-emb       4.4.0.206.212
  linux-image-powerpc64-smp       4.4.0.206.212
  linux-image-snapdragon          4.4.0.1152.144
  linux-image-virtual             4.4.0.206.212
  linux-image-virtual-hwe-16.04   4.15.0.139.134

Ubuntu 14.04 ESM:
  linux-image-4.15.0-1110-azure   4.15.0-1110.122~14.04.1
  linux-image-4.4.0-1088-aws      4.4.0-1088.92
  linux-image-aws                 4.4.0.1088.85
  linux-image-azure               4.15.0.1110.83

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:
  https://ubuntu.com/security/notices/USN-4883-1
  CVE-2021-27363, CVE-2021-27364, CVE-2021-27365

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.15.0-139.143
  https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1096.103
  https://launchpad.net/ubuntu/+source/linux-azure-4.15/4.15.0-1110.122
  https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1095.108
  https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1087.89
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1081.86
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1098.107
  https://launchpad.net/ubuntu/+source/linux/4.4.0-206.238
  https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1124.138
  https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1096.103~16.04.1
  https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1110.122~16.04.1
  https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1095.108~16.04.1
  https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-139.143~16.04.1
  https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1090.99
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1152.162