USN-2849-1: Linux kernel (Utopic HWE) vulnerabilities
Ubuntu Security Notice USN-2849-1
19th December, 2015
linux-lts-utopic vulnerabilities
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 14.04 LTS
Summary
Several security issues were fixed in the kernel.
Software description
- linux-lts-utopic - Linux hardware enablement kernel from Utopic
Details
Felix Wilhelm discovered a race condition in the Xen paravirtualized
drivers which can cause double fetch vulnerabilities. An attacker in the
paravirtualized guest could exploit this flaw to cause a denial of service
(crash the host) or potentially execute arbitrary code on the host.
(CVE-2015-8550)
Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not
perform sanity checks on the device's state. An attacker could exploit this
flaw to cause a denial of service (NULL dereference) on the host.
(CVE-2015-8551)
Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not
perform sanity checks on the device's state. An attacker could exploit this
flaw to cause a denial of service by flooding the logging system with
WARN() messages causing the initial domain to exhaust disk space.
(CVE-2015-8552)
Jann Horn discovered a ptrace issue with user namespaces in the Linux
kernel. The namespace owner could potentially exploit this flaw by ptracing
a root owned process entering the user namespace to elevate its privileges
and potentially gain access outside of the namespace.
(http://ift.tt/1NvLaK8)
Update instructions
The problem can be corrected by updating your system to the following package version:
- Ubuntu 14.04 LTS:
- linux-image-3.16.0-57-generic-lpae 3.16.0-57.77~14.04.1
- linux-image-3.16.0-57-lowlatency 3.16.0-57.77~14.04.1
- linux-image-3.16.0-57-powerpc-e500mc 3.16.0-57.77~14.04.1
- linux-image-3.16.0-57-powerpc64-emb 3.16.0-57.77~14.04.1
- linux-image-3.16.0-57-powerpc64-smp 3.16.0-57.77~14.04.1
- linux-image-3.16.0-57-generic 3.16.0-57.77~14.04.1
- linux-image-3.16.0-57-powerpc-smp 3.16.0-57.77~14.04.1
To update your system, please follow these instructions: http://ift.tt/17VXqjU.
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-2015-8550, CVE-2015-8551, CVE-2015-8552, CVE-2015-NNN2
from Ubuntu Security Notices http://ift.tt/1OfNZCl