1. Ubuntu Security Notices
  2. USN-2840-1

USN-2840-1: Linux kernel vulnerabilities

Publication date

17 December 2015

Overview

Several security issues were fixed in the kernel.

Releases

Packages

Details

Dmitry Vyukov discovered that the Linux kernel's keyring handler attempted
to garbage collect incompletely instantiated keys. A local unprivileged
attacker could use this to cause a denial of service (system crash).
(CVE-2015-7872)

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)

Dmitry Vyukov discovered that the Linux kernel's keyring handler attempted
to garbage collect incompletely instantiated keys. A local unprivileged
attacker could use this to cause a denial of service (system crash).
(CVE-2015-7872)

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)

Update instructions

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
12.04 precise linux-image-3.2.0-96-generic –  3.2.0-96.136
linux-image-3.2.0-96-powerpc-smp –  3.2.0-96.136
linux-image-3.2.0-96-virtual –  3.2.0-96.136
linux-image-3.2.0-96-highbank –  3.2.0-96.136
linux-image-3.2.0-96-omap –  3.2.0-96.136
linux-image-3.2.0-96-generic-pae –  3.2.0-96.136
linux-image-3.2.0-96-powerpc64-smp –  3.2.0-96.136

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References

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