linux - security update

Several vulnerabilities have been discovered in the Linux kernel that
may lead to a privilege escalation or denial of service.

• CVE-2015-8215
  It was discovered that NetworkManager would set IPv6 MTUs based on
  the values received in IPv6 RAs (Router Advertisements), without
  sufficiently validating these values. A remote attacker could
  exploit this attack to disable IPv6 connectivity. This has been
  mitigated by adding validation in the kernel.
• CVE-2015-2925
  Jann Horn discovered that when a subdirectory of a filesystem is
  bind-mounted into a container that has its own user and mount
  namespaces, a process with CAP_SYS_ADMIN capability in the user
  namespace can access files outside of the subdirectory. The
  default Debian configuration mitigated this as it does not allow
  unprivileged users to create new user namespaces.
• CVE-2015-5156
  Jason Wang discovered that when a virtio_net device is connected
  to a bridge in the same VM, a series of TCP packets forwarded
  through the bridge may cause a heap buffer overflow. A remote
  attacker could use this to cause a denial of service (crash) or
  possibly for privilege escalation.
• CVE-2015-6252
  Michael S. Tsirkin of Red Hat Engineering found that the vhost
  driver leaked file descriptors passed to it with the
  VHOST_SET_LOG_FD ioctl command. A privileged local user with access
  to the /dev/vhost-net file, either directly or via libvirt, could
  use this to cause a denial of service (hang or crash).
• CVE-2015-6937
  It was found that the Reliable Datagram Sockets (RDS) protocol
  implementation did not verify that an underlying transport exists
  when creating a connection. Depending on how a local RDS
  application initialised its sockets, a remote attacker might be
  able to cause a denial of service (crash) by sending a crafted
  packet.
• CVE-2015-7312
  Xavier Chantry discovered that the patch provided by the aufs
  project to correct behaviour of memory-mapped files from an aufs
  mount introduced a race condition in the msync() system call.
  Ben Hutchings found that it also introduced a similar bug in the
  madvise_remove() function. A local attacker could use this to
  cause a denial of service or possibly for privilege escalation.

For the oldstable distribution (wheezy), these problems have been fixed
in version 3.2.68-1+deb7u4.
CVE-2015-2925 and
CVE-2015-7312 do
not affect the wheezy distribution.

For the stable distribution (jessie), these problems have been fixed in
version 3.16.7-ckt11-1+deb8u4.

We recommend that you upgrade your linux packages.