linux - security update

Several vulnerabilities have been discovered in the Linux kernel that
may lead to a denial of service:

• CVE-2014-3610
  Lars Bull of Google and Nadav Amit reported a flaw in how KVM
  handles noncanonical writes to certain MSR registers. A privileged
  guest user can exploit this flaw to cause a denial of service
  (kernel panic) on the host.
• CVE-2014-3611
  Lars Bull of Google reported a race condition in the PIT
  emulation code in KVM. A local guest user with access to PIT i/o
  ports could exploit this flaw to cause a denial of service (crash)
  on the host.
• CVE-2014-3645

/ CVE-2014-3646
The Advanced Threat Research team at Intel Security discovered
that the KVM subsystem did not handle the VM exits gracefully
for the invept (Invalidate Translations Derived from EPT) and
invvpid (Invalidate Translations Based on VPID) instructions. On
hosts with an Intel processor and invept/invppid VM exit
support, an unprivileged guest user could use these instructions
to crash the guest.

• CVE-2014-3647
  Nadav Amit reported that KVM mishandles noncanonical addresses when
  emulating instructions that change rip, potentially causing a failed
  VM-entry. A guest user with access to I/O or the MMIO can use this
  flaw to cause a denial of service (system crash) of the guest.
• CVE-2014-3673
  Liu Wei of Red Hat discovered a flaw in net/core/skbuff.c leading to
  a kernel panic when receiving malformed ASCONF chunks. A remote
  attacker could use this flaw to crash the system.
• CVE-2014-3687
  A flaw in the sctp stack was discovered leading to a kernel panic
  when receiving duplicate ASCONF chunks. A remote attacker could use
  this flaw to crash the system.
• CVE-2014-3688
  It was found that the sctp stack is prone to a remotely triggerable
  memory pressure issue caused by excessive queueing. A remote
  attacker could use this flaw to cause denial-of-service conditions
  on the system.
• CVE-2014-3690
  Andy Lutomirski discovered that incorrect register handling in KVM
  may lead to denial of service.
• CVE-2014-7207
  Several Debian developers reported an issue in the IPv6 networking
  subsystem. A local user with access to tun or macvtap devices, or a
  virtual machine connected to such a device, can cause a denial of
  service (system crash).

This update includes a bug fix related to CVE-2014-7207 that disables
UFO (UDP Fragmentation Offload) in the macvtap, tun, and virtio_net
drivers. This will cause migration of a running VM from a host running
an earlier kernel version to a host running this kernel version to fail,
if the VM has been assigned a virtio network device. In order to migrate
such a VM, it must be shut down first.

For the stable distribution (wheezy), these problems have been fixed in
version 3.2.63-2+deb7u1.

We recommend that you upgrade your linux packages.