linux-2.6 - security update

This update fixes the CVEs described below.

• CVE-2015-2925
  Jann Horn discovered that when a subdirectory of a filesystem was
  bind-mounted into a chroot or mount namespace, a user that should
  be confined to that chroot or namespace could access the whole of
  that filesystem if they had write permission on an ancestor of
  the subdirectory. This is not a common configuration for this
  kernel version.
• CVE-2015-5257
  Moein Ghasemzadeh of Istuary Innovation Labs reported that a USB
  device could cause a denial of service (crash) by imitating a
  Whiteheat USB serial device but presenting a smaller number of
  endpoints.
• CVE-2015-7613
  Dmitry Vyukov discovered that System V IPC objects (message queues
  and shared memory segments) were made accessible before their
  ownership and other attributes were fully initialised. If a local
  user can race against another user or service creating a new IPC
  object, this may result in unauthorised information disclosure,
  unauthorised information modification, denial of service and/or
  privilege escalation.

A similar issue existed with System V semaphore arrays, but was
less severe because they were always cleared before being fully
initialised.

For the oldoldstable distribution (squeeze), these problems have been
fixed in version 2.6.32-48squeeze16.

For the oldstable distribution (wheezy), these problems will be fixed
in version 3.2.68-1+deb7u5.

For the stable distribution (jessie), these problems will be fixed
in version 3.16.7-ckt11-1+deb8u5 or have been fixed earlier.