============================================================================
Ubuntu Security Notice USN-2448-1
December 12, 2014

linux vulnerabilities
============================================================================

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

- Ubuntu 14.10

Summary:

Several security issues were fixed in the kernel.

Software Description:
- linux: Linux kernel

Details:

An information leak in the Linux kernel was discovered that could leak the
high 16 bits of the kernel stack address on 32-bit Kernel Virtual Machine
(KVM) paravirt guests. A user in the guest OS could exploit this leak to
obtain information that could potentially be used to aid in attacking the
kernel. (CVE-2014-8134)

Rabin Vincent, Robert Swiecki, Russell King discovered that the ftrace
subsystem of the Linux kernel does not properly handle private syscall
numbers. A local user could exploit this flaw to cause a denial of service
(OOPS). (CVE-2014-7826)

A flaw in the handling of malformed ASCONF chunks by SCTP (Stream Control
Transmission Protocol) implementation in the Linux kernel was discovered. A
remote attacker could exploit this flaw to cause a denial of service
(system crash). (CVE-2014-3673)

A flaw in the handling of duplicate ASCONF chunks by SCTP (Stream Control
Transmission Protocol) implementation in the Linux kernel was discovered. A
remote attacker could exploit this flaw to cause a denial of service
(panic). (CVE-2014-3687)

It was discovered that excessive queuing by SCTP (Stream Control
Transmission Protocol) implementation in the Linux kernel can cause memory
pressure. A remote attacker could exploit this flaw to cause a denial of
service. (CVE-2014-3688)

Rabin Vincent, Robert Swiecki, Russell Kinglaw discovered a flaw in how the
perf subsystem of the Linux kernel handles private systecall numbers. A
local user could exploit this to cause a denial of service (OOPS) or bypass
ASLR protections via a crafted application. (CVE-2014-7825)

Andy Lutomirski discovered a flaw in how the Linux kernel handles
pivot_root when used with a chroot directory. A local user could exploit
this flaw to cause a denial of service (mount-tree loop). (CVE-2014-7970)

Dmitry Monakhov discovered a race condition in the ext4_file_write_iter
function of the Linux kernel's ext4 filesystem. A local user could exploit
this flaw to cause a denial of service (file unavailability).
(CVE-2014-8086)

The KVM (kernel virtual machine) subsystem of the Linux kernel
miscalculates the number of memory pages during the handling of a mapping
failure. A guest OS user could exploit this to cause a denial of service
(host OS page unpinning) or possibly have unspecified other impact by
leveraging guest OS privileges. (CVE-2014-8369)

Andy Lutomirski discovered that the Linux kernel does not properly handle
faults associated with the Stack Segment (SS) register on the x86
architecture. A local attacker could exploit this flaw to cause a denial of
service (panic). (CVE-2014-9090)

Update instructions:

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

Ubuntu 14.10:
  linux-image-3.16.0-28-generic   3.16.0-28.37
  linux-image-3.16.0-28-generic-lpae  3.16.0-28.37
  linux-image-3.16.0-28-lowlatency  3.16.0-28.37
  linux-image-3.16.0-28-powerpc-e500mc  3.16.0-28.37
  linux-image-3.16.0-28-powerpc-smp  3.16.0-28.37
  linux-image-3.16.0-28-powerpc64-emb  3.16.0-28.37
  linux-image-3.16.0-28-powerpc64-smp  3.16.0-28.37

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:
  http://www.ubuntu.com/usn/usn-2448-1
  CVE-2014-3673, CVE-2014-3687, CVE-2014-3688, CVE-2014-7825,
  CVE-2014-7826, CVE-2014-7970, CVE-2014-8086, CVE-2014-8134,
  CVE-2014-8369, CVE-2014-9090

Package Information:
  https://launchpad.net/ubuntu/+source/linux/3.16.0-28.37