Univention Corporate Server 4.2 erratum 257 (security)

This update of the Linux kernel to version 4.9.75 addresses the following
issues:
* ALSA: pcm: prevent UAF in snd_pcm_info (CVE-2017-0861)
* "Dirty COW" variant on transparent huge pages (CVE-2017-1000405)
* KVM: DoS via write flood to I/O port 0x80 (CVE-2017-1000407)
* bpf: fix incorrect sign extension in check_alu_op() (CVE-2017-16995)
* memory corruption in USB core subsystem (CVE-2017-17558)
* crypto: salsa20 - fix blkcipher_walk API usage (CVE-2017-17805)
* crypto: hmac - require that the underlying hash algorithm is unkeyed
  (CVE-2017-17806)
* KEYS: add missing permission check for request_key() destination
  (CVE-2017-17807)
* bpf: fix branch pruning logic (CVE-2017-17862)
* sctp: use-after-free in sctp_cmp_addr_exact() (CVE-2017-15115)
* cx231xx-cards: fix NULL-deref on missing association descriptor
  (CVE-2017-16536)
* net: usb: asix: fill null-ptr-deref in asix_suspend (CVE-2017-16647)
* net: cdc_ether: fix divide by 0 on bad descriptors (CVE-2017-16649)
* net: qmi_wwan: fix divide by 0 on bad descriptors (CVE-2017-16650)
* Information Leak in mincore() (CVE-2017-16994)
* bpf: reject out-of-bounds stack pointer calculation (CVE-2017-17863)
* netlink: Add netns check on taps (CVE-2017-17449)
* net: ipv4: fix for a race condition in raw_sendmsg (CVE-2017-17712)
* Systems with microprocessors utilizing speculative execution and indirect
  branch prediction may allow unauthorized disclosure of information to an
  attacker with local user access via a side-channel analysis of the data
  cache. (CVE-2017-5754)