USN-4135-2: Linux kernel vulnerabilities

18 September 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-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-lts-trusty - Linux hardware enablement kernel from Trusty for Precise ESM
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

Peter Pi discovered a buffer overflow in the virtio network backend
(vhost_net) implementation in the Linux kernel. An attacker in a guest may
be able to use this to cause a denial of service (host OS crash) or
possibly execute arbitrary code in the host OS. (CVE-2019-14835)

It was discovered that the Linux kernel on PowerPC architectures did not
properly handle Facility Unavailable exceptions in some situations. A local
attacker could use this to expose sensitive information. (CVE-2019-15030)

It was discovered that the Linux kernel on PowerPC architectures did not
properly handle exceptions on interrupts in some situations. A local
attacker could use this to expose sensitive information. (CVE-2019-15031)

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 14.04
Ubuntu 12.04

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.

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