linux - security update

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

• CVE-2013-7446
  Dmitry Vyukov discovered that a particular sequence of valid
  operations on local (AF_UNIX) sockets can result in a
  use-after-free. This may be used to cause a denial of service
  (crash) or possibly for privilege escalation.
• CVE-2015-7799
  It was discovered that a user granted access to /dev/ppp can cause a
  denial of service (crash) by passing invalid parameters to the
  PPPIOCSMAXCID ioctl. This also applies to ISDN PPP device nodes.
• CVE-2015-7833
  Sergej Schumilo, Hendrik Schwartke and Ralf Spenneberg discovered a
  flaw in the processing of certain USB device descriptors in the
  usbvision driver. An attacker with physical access to the system can
  use this flaw to crash the system. This was partly fixed by the
  changes listed in DSA 3396-1.
• CVE-2015-8104
  Jan Beulich reported a guest to host denial-of-service flaw
  affecting the KVM hypervisor running on AMD processors. A malicious
  guest can trigger an infinite stream of debug (#DB) exceptions
  causing the processor microcode to enter an infinite loop where the
  core never receives another interrupt. This leads to a panic of the
  host kernel.
• CVE-2015-8374
  It was discovered that Btrfs did not correctly implement truncation
  of compressed inline extents. This could lead to an information
  leak, if a file is truncated and later made readable by other users.
  Additionally, it could cause data loss. This has been fixed for the
  stable distribution (jessie) only.
• CVE-2015-8543
  It was discovered that a local user permitted to create raw sockets
  could cause a denial-of-service by specifying an invalid protocol
  number for the socket. The attacker must have the CAP_NET_RAW
  capability in their user namespace. This has been fixed for the
  stable distribution (jessie) only.

For the oldstable distribution (wheezy), these problems have been fixed
in version 3.2.73-2+deb7u1. In addition, this update contains several
changes originally targeted for the upcoming Wheezy point release.

For the stable distribution (jessie), these problems have been fixed in
version 3.16.7-ckt20-1+deb8u1. In addition, this update contains several
changes originally targeted for the upcoming Jessie point release.

We recommend that you upgrade your linux packages.