USN-2842-1: Linux kernel vulnerabilities

Ubuntu Security Notice USN-2842-1

17th December, 2015

linux vulnerabilities

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

  • Ubuntu 15.04

Summary

Several security issues were fixed in the kernel.

Software description

  • linux - Linux kernel

Details

Jan Beulich discovered that the KVM svm hypervisor implementation in the
Linux kernel did not properly catch Debug exceptions on AMD processors. An
attacker in a guest virtual machine could use this to cause a denial of
service (system crash) in the host OS. (CVE-2015-8104)

郭永刚 discovered that the ppp implementation in the Linux kernel did
not ensure that certain slot numbers are valid. A local attacker with the
privilege to call ioctl() on /dev/ppp could cause a denial of service
(system crash). (CVE-2015-7799)

It was discovered that the virtual video osd test driver in the Linux
kernel did not properly initialize data structures. A local attacker could
use this to obtain sensitive information from the kernel. (CVE-2015-7884)

It was discovered that the driver for Digi Neo and ClassicBoard devices did
not properly initialize data structures. A local attacker could use this to
obtain sensitive information from the kernel. (CVE-2015-7885)

Update instructions

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

Ubuntu 15.04:
linux-image-3.19.0-41-powerpc64-emb 3.19.0-41.46
linux-image-3.19.0-41-generic 3.19.0-41.46
linux-image-3.19.0-41-powerpc64-smp 3.19.0-41.46
linux-image-3.19.0-41-powerpc-e500mc 3.19.0-41.46
linux-image-3.19.0-41-lowlatency 3.19.0-41.46
linux-image-3.19.0-41-generic-lpae 3.19.0-41.46
linux-image-3.19.0-41-powerpc-smp 3.19.0-41.46

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. If
you use linux-restricted-modules, you have to update that package as
well to get modules which work with the new kernel version. Unless you
manually uninstalled the standard kernel metapackages (e.g. linux-generic,
linux-server, linux-powerpc), a standard system upgrade will automatically
perform this as well.

References

CVE-2015-7799, CVE-2015-7884, CVE-2015-7885, CVE-2015-8104