Univention Corporate Server 4.0 erratum 428 (security)

This update addresses the following issues:
* unix: properly account for FDs passed over unix sockets (CVE-2013-4312)
* The fuse_fill_write_pages function in fs/fuse/file.c in the Linux kernel
  before 4.4 allows local users to cause a denial of service (infinite loop)
  via a writev system call that triggers a zero length for the first segment
  of an iov. (CVE-2015-8785)
* Flaw in CXGB3 driver (CVE-2015-8812)
* USB hub invalid memory access in hub_activate() (CVE-2015-8816)
* aio write triggers integer overflow in some network protocols
  (CVE-2015-8830)
* x86 Linux TLB flush bug (CVE-2016-2069)
* Double-free in snd-usbmidi-lib triggered by invalid USB descriptor
  (CVE-2016-2384)
* ALSA: seq: Fix missing NULL check at remove_events ioctl (CVE-2016-2543)
* ALSA: seq: Fix race at timer setup and close (CVE-2016-2544)
* ALSA: timer: Fix double unlink of active_list (CVE-2016-2545)
* ALSA: timer: Fix race among timer ioctls (CVE-2016-2546)
* ALSA: use-after-free in snd_timer_user_ioctl (CVE-2016-2547)
* ALSA: linked lists of slave instances not unlinked immediately
  (CVE-2016-2548)
* ALSA: hrtimer: Fix stall by hrtimer_cancel() (CVE-2016-2549)
* unix: correctly track in-flight fds in sending process user_struct
  (CVE-2016-2550
* pipe: limit the per-user amount of pages allocated in pipes (CVE-2016-2847)
* aiptek: crash on invalid USB device descriptors (CVE-2015-7515)
* aio write triggers integer overflow in some network protocols
  (CVE-2015-8830)
* Too big poison pointer space (CVE-2016-0821)
* Kernel panic on invalid USB device descriptor (snd_usb_audio driver)
  (CVE-2016-2184)
* Kernel panic on invalid USB device descriptor (ati_remote2 driver)
  (CVE-2016-2185)
* Kernel panic on invalid USB device descriptor (powermate driver)
  (CVE-2016-2186)
* Kernel panic on invalid USB device descriptor (iowarrior driver)
  (CVE-2016-2188)
* crash on invalid USB device descriptors (cdc_acm driver) (CVE-2016-3138)
* ipv4: Don't do expensive useless work during inetdev destroy
  (CVE-2016-3156)
* I/O port access privilege escalation in x86-64 Linux under Xen
  (CVE-2016-3157)
* usbnet: memory corruption triggered by invalid USB descriptor
  (CVE-2016-3951)
* Partial SMAP bypass on 64-bit Linux kernels (CVE-2016-partial-SMAP-bypass)