linux-2.6 - security update

This update fixes the CVEs described below.

• 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
  郭永刚 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.
• CVE-2015-7990
  It was discovered that the fix for CVE-2015-6937 was incomplete. A
  race condition when sending a message on unbound socket can still
  cause a NULL pointer dereference. A remote attacker might be able to
  cause a denial of service (crash) by sending a crafted packet.
• CVE-2015-8324
  Valintinr reported that an attempt to mount a corrupted ext4
  filesystem may result in a kernel panic. A user permitted to
  mount filesystems could use this flaw to crash the system.

For the oldoldstable distribution (squeeze), these problems have been
fixed in version 2.6.32-48squeeze17. We recommend that you upgrade your
linux-2.6 packages.

For the oldstable (wheezy) and stable (jessie) distributions,
CVE-2015-7833, CVE-2015-7990 and CVE-2015-8324 have been fixed and the
other issues will be fixed soon.