USN-3443-1: Linux kernel vulnerabilities

Ubuntu Security Notice USN-3443-1

10th October, 2017

linux, linux-raspi2 vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 17.04

Summary

Several security issues were fixed in the Linux kernel.

Software description

  • linux - Linux kernel
  • linux-raspi2 - Linux kernel for Raspberry Pi 2

Details

It was discovered that on the PowerPC architecture, the kernel did not
properly sanitize the signal stack when handling sigreturn(). A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2017-1000255)

Andrey Konovalov discovered that a divide-by-zero error existed in the TCP
stack implementation in the Linux kernel. A local attacker could use this
to cause a denial of service (system crash). (CVE-2017-14106)

Update instructions

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

Ubuntu 17.04:
linux-image-powerpc-smp 4.10.0.37.37
linux-image-powerpc-e500mc 4.10.0.37.37
linux-image-4.10.0-37-lowlatency 4.10.0-37.41
linux-image-generic-lpae 4.10.0.37.37
linux-image-lowlatency 4.10.0.37.37
linux-image-virtual 4.10.0.37.37
linux-image-4.10.0-1019-raspi2 4.10.0-1019.22
linux-image-powerpc64-smp 4.10.0.37.37
linux-image-generic 4.10.0.37.37
linux-image-4.10.0-37-generic-lpae 4.10.0-37.41
linux-image-4.10.0-37-generic 4.10.0-37.41
linux-image-powerpc64-emb 4.10.0.37.37
linux-image-raspi2 4.10.0.1019.20

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.

References

CVE-2017-1000255, CVE-2017-14106