USN-2847-1: Linux kernel (Trusty HWE) vulnerabilities

19 December 2015

Several security issues were fixed in the kernel.

Releases

Packages

  • linux-lts-trusty - Linux hardware enablement kernel from Trusty

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://bugs.launchpad.net/bugs/1527374, CVE-2015-8709)

Update instructions

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

Ubuntu 12.04

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.

Related notices

  • USN-2854-1: linux-image-3.19.0-42-generic-lpae, linux-image-3.19.0-42-lowlatency, linux-image-3.19.0-42-powerpc-smp, linux-image-3.19.0-42-powerpc64-smp, linux-image-3.19.0-42-powerpc64-emb, linux-image-3.19.0-42-powerpc-e500mc, linux-lts-vivid, linux-image-3.19.0-42-generic
  • USN-2891-1: qemu-system-misc, qemu-system-sparc, qemu-system-x86, qemu-system, qemu-kvm, qemu-system-aarch64, qemu-system-arm, qemu, qemu-system-mips, qemu-system-ppc
  • USN-2852-1: linux-image-4.2.0-1017-raspi2, linux-raspi2
  • USN-2886-2: linux-ti-omap4, linux-image-3.2.0-1476-omap4
  • USN-2851-1: linux-image-4.2.0-22-powerpc64-smp, linux-image-4.2.0-22-powerpc-e500mc, linux-image-4.2.0-22-powerpc64-emb, linux-image-4.2.0-22-lowlatency, linux-image-4.2.0-22-generic-lpae, linux-image-4.2.0-22-powerpc-smp, linux, linux-image-4.2.0-22-generic
  • USN-2849-1: linux-image-3.16.0-57-powerpc64-emb, linux-image-3.16.0-57-lowlatency, linux-image-3.16.0-57-powerpc-smp, linux-image-3.16.0-57-generic, linux-image-3.16.0-57-generic-lpae, linux-lts-utopic, linux-image-3.16.0-57-powerpc64-smp, linux-image-3.16.0-57-powerpc-e500mc
  • USN-2848-1: linux-image-3.13.0-74-powerpc-e500, linux-image-3.13.0-74-generic-lpae, linux-image-3.13.0-74-powerpc64-emb, linux-image-3.13.0-74-powerpc-e500mc, linux-image-3.13.0-74-lowlatency, linux-image-3.13.0-74-powerpc64-smp, linux-image-3.13.0-74-generic, linux, linux-image-3.13.0-74-powerpc-smp
  • USN-2850-1: linux-image-3.19.0-42-generic-lpae, linux-image-3.19.0-42-lowlatency, linux-image-3.19.0-42-powerpc-smp, linux-image-3.19.0-42-powerpc64-smp, linux-image-3.19.0-42-powerpc64-emb, linux-image-3.19.0-42-powerpc-e500mc, linux, linux-image-3.19.0-42-generic
  • USN-2853-1: linux-image-4.2.0-22-powerpc64-smp, linux-image-4.2.0-22-powerpc-e500mc, linux-image-4.2.0-22-powerpc64-emb, linux-image-4.2.0-22-lowlatency, linux-lts-wily, linux-image-4.2.0-22-generic-lpae, linux-image-4.2.0-22-powerpc-smp, linux-image-4.2.0-22-generic
  • USN-2846-1: linux-image-3.2.0-97-virtual, linux-image-3.2.0-97-highbank, linux-image-3.2.0-97-powerpc64-smp, linux-image-3.2.0-97-generic, linux-image-3.2.0-97-powerpc-smp, linux-image-3.2.0-97-omap, linux, linux-image-3.2.0-97-generic-pae