USN-4076-1: Linux kernel vulnerabilities

25 July 2019

Several security issues were fixed in the Linux kernel.

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Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-kvm - Linux kernel for cloud environments
  • linux-raspi2 - Linux kernel for Raspberry Pi 2

Details

It was discovered that a race condition existed in the Serial Attached SCSI
(SAS) implementation in the Linux kernel. A local attacker could possibly
use this to cause a denial of service (system crash) or execute arbitrary
code. (CVE-2018-20836)

It was discovered that the ext4 file system implementation in the Linux
kernel did not properly zero out memory in some situations. A local
attacker could use this to expose sensitive information (kernel memory).
(CVE-2019-11833)

It was discovered that the Bluetooth Human Interface Device Protocol (HIDP)
implementation in the Linux kernel did not properly verify strings were
NULL terminated in certain situations. A local attacker could use this to
expose sensitive information (kernel memory). (CVE-2019-11884)

It was discovered that the Linux kernel on ARM processors allowed a tracing
process to modify a syscall after a seccomp decision had been made on that
syscall. A local attacker could possibly use this to bypass seccomp
restrictions. (CVE-2019-2054)

Hugues Anguelkov discovered that the Broadcom Wifi driver in the Linux
kernel did not properly prevent remote firmware events from being processed
for USB Wifi devices. A physically proximate attacker could use this to
send firmware events to the device. (CVE-2019-9503)

It was discovered that an integer overflow existed in the Freescale
(PowerPC) hypervisor manager in the Linux kernel. A local attacker with
write access to /dev/fsl-hv could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2019-10142)

Reduce your security exposure

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.

Learn more about Ubuntu Pro

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.