USN-2824-1: Linux kernel (Utopic HWE) vulnerability

Ubuntu Security Notice USN-2824-1

1st December, 2015

linux-lts-utopic vulnerability

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

• Ubuntu 14.04 LTS

Summary

The system could be made to crash under certain conditions.

Software description

• linux-lts-utopic - Linux hardware enablement kernel from Utopic

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).

Update instructions

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

Ubuntu 14.04 LTS:

linux-image-3.16.0-55-powerpc64-smp 3.16.0-55.74~14.04.1

linux-image-3.16.0-55-lowlatency 3.16.0-55.74~14.04.1

linux-image-3.16.0-55-generic 3.16.0-55.74~14.04.1

linux-image-3.16.0-55-generic-lpae 3.16.0-55.74~14.04.1

linux-image-3.16.0-55-powerpc-e500mc 3.16.0-55.74~14.04.1

linux-image-3.16.0-55-powerpc64-emb 3.16.0-55.74~14.04.1

linux-image-3.16.0-55-powerpc-smp 3.16.0-55.74~14.04.1

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-2015-7872