USN-4254-1: Linux kernel vulnerabilities

28 January 2020

Several security issues were fixed in the Linux kernel.

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Releases

Packages

Details

It was discovered that the Linux kernel did not properly clear data
structures on context switches for certain Intel graphics processors. A
local attacker could use this to expose sensitive information.
(CVE-2019-14615)

It was discovered that a race condition existed in the Virtual Video Test
Driver in the Linux kernel. An attacker with write access to /dev/video0 on
a system with the vivid module loaded could possibly use this to gain
administrative privileges. (CVE-2019-18683)

It was discovered that the btrfs file system in the Linux kernel did not
properly validate metadata, leading to a NULL pointer dereference. An
attacker could use this to specially craft a file system image that, when
mounted, could cause a denial of service (system crash). (CVE-2019-18885)

It was discovered that multiple memory leaks existed in the Marvell WiFi-Ex
Driver for the Linux kernel. A local attacker could possibly use this to
cause a denial of service (kernel memory exhaustion). (CVE-2019-19057)

It was discovered that the crypto subsystem in the Linux kernel did not
properly deallocate memory in certain error conditions. A local attacker
could use this to cause a denial of service (kernel memory exhaustion).
(CVE-2019-19062)

It was discovered that the Realtek rtlwifi USB device driver in the Linux
kernel did not properly deallocate memory in certain error conditions. A
local attacker could possibly use this to cause a denial of service (kernel
memory exhaustion). (CVE-2019-19063)

Dan Carpenter discovered that the AppleTalk networking subsystem of the
Linux kernel did not properly handle certain error conditions, leading to a
NULL pointer dereference. A local attacker could use this to cause a denial
of service (system crash). (CVE-2019-19227)

It was discovered that the KVM hypervisor implementation in the Linux
kernel did not properly handle ioctl requests to get emulated CPUID
features. An attacker with access to /dev/kvm could use this to cause a
denial of service (system crash). (CVE-2019-19332)

It was discovered that the B2C2 FlexCop USB device driver in the Linux
kernel did not properly validate device metadata. A physically proximate
attacker could use this to cause a denial of service (system crash).
(CVE-2019-15291)

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Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

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Update instructions

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

Ubuntu 16.04

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.