USN-3901-1: Linux kernel vulnerabilities
linux, linux-aws, linux-gcp, linux-kvm, linux-oem, linux-oracle, linux-raspi2 vulnerabilities
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.04 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-gcp – Linux kernel for Google Cloud Platform (GCP) systems
- linux-kvm – Linux kernel for cloud environments
- linux-oem – Linux kernel for OEM processors
- linux-oracle – Linux kernel for Oracle Cloud systems
- linux-raspi2 – Linux kernel for Raspberry Pi 2
Details
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)
It was discovered that the crypto subsystem of the Linux kernel leaked
uninitialized memory to user space in some situations. A local attacker
could use this to expose sensitive information (kernel memory).
(CVE-2018-19854)
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 18.04 LTS
- linux-image-4.15.0-1009-oracle – 4.15.0-1009.11
- linux-image-4.15.0-1028-gcp – 4.15.0-1028.29
- linux-image-4.15.0-1030-kvm – 4.15.0-1030.30
- linux-image-4.15.0-1032-raspi2 – 4.15.0-1032.34
- linux-image-4.15.0-1033-aws – 4.15.0-1033.35
- linux-image-4.15.0-1034-oem – 4.15.0-1034.39
- linux-image-4.15.0-46-generic – 4.15.0-46.49
- linux-image-4.15.0-46-generic-lpae – 4.15.0-46.49
- linux-image-4.15.0-46-lowlatency – 4.15.0-46.49
- linux-image-4.15.0-46-snapdragon – 4.15.0-46.49
- linux-image-aws – 4.15.0.1033.32
- linux-image-gcp – 4.15.0.1028.30
- linux-image-generic – 4.15.0.46.48
- linux-image-generic-lpae – 4.15.0.46.48
- linux-image-gke – 4.15.0.1028.30
- linux-image-kvm – 4.15.0.1030.30
- linux-image-lowlatency – 4.15.0.46.48
- linux-image-oem – 4.15.0.1034.39
- linux-image-oracle – 4.15.0.1009.12
- linux-image-raspi2 – 4.15.0.1032.30
- linux-image-snapdragon – 4.15.0.46.48
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.