USN-3903-1: Linux kernel vulnerabilities
linux, linux-azure, linux-gcp, linux-kvm, linux-raspi2 vulnerabilities
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.10
Summary
Several security issues were fixed in the Linux kernel.
Software Description
- linux – Linux kernel
- 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-raspi2 – Linux kernel for Raspberry Pi 2
Details
Jason Wang discovered that the vhost net driver in the Linux kernel
contained an out of bounds write vulnerability. An attacker in a guest
virtual machine could use this to cause a denial of service (host system
crash) or possibly execute arbitrary code in the host kernel.
(CVE-2018-16880)
Jann Horn discovered that the userfaultd implementation in the Linux kernel
did not properly restrict access to certain ioctls. A local attacker could
use this possibly to modify files. (CVE-2018-18397)
Jann Horn discovered a race condition in the fork() system call in the
Linux kernel. A local attacker could use this to gain access to services
that cache authorizations. (CVE-2019-6133)
Update instructions
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 18.10
- linux-image-4.18.0-1007-gcp – 4.18.0-1007.8
- linux-image-4.18.0-1008-kvm – 4.18.0-1008.8
- linux-image-4.18.0-1010-raspi2 – 4.18.0-1010.12
- linux-image-4.18.0-1013-azure – 4.18.0-1013.13
- linux-image-4.18.0-16-generic – 4.18.0-16.17
- linux-image-4.18.0-16-generic-lpae – 4.18.0-16.17
- linux-image-4.18.0-16-lowlatency – 4.18.0-16.17
- linux-image-4.18.0-16-snapdragon – 4.18.0-16.17
- linux-image-azure – 4.18.0.1013.14
- linux-image-gcp – 4.18.0.1007.7
- linux-image-generic – 4.18.0.16.17
- linux-image-generic-lpae – 4.18.0.16.17
- linux-image-gke – 4.18.0.1007.7
- linux-image-kvm – 4.18.0.1008.8
- linux-image-lowlatency – 4.18.0.16.17
- linux-image-raspi2 – 4.18.0.1010.7
- linux-image-snapdragon – 4.18.0.16.17
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
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.