[ELSA-2018-4041] Unbreakable Enterprise kernel security update

[2.6.39-400.298.3]
- ext4: limit group search loop for non-extent files (Lachlan McIlroy) [Orabug: 17488415]
- ext4: fixup 64-bit divides in 3.0-stable backport of upstream fix (Todd Poynor) [Orabug: 17488415]
- ext4: use atomic64_t for the per-flexbg free_clusters count (Theodore Ts'o) [Orabug: 17488415]
- ext4: init pagevec in ext4_da_block_invalidatepages (Eric Sandeen) [Orabug: 17488415]
- ext4: do not try to write superblock on ro remount w/o journal (Michael Tokarev) [Orabug: 17488415]
- xen-netback: fix grant_copy_op array size (Niranjan Patil) [Orabug: 25653941]
- xen-netback: explicitly check max_slots_needed against meta_prod counter (Niranjan Patil) [Orabug: 25653941]
- xen-netback: Fix handling of skbs requiring too many slots (Zoltan Kiss) [Orabug: 25653941]
- xen-netback: worse-case estimate in xenvif_rx_action is underestimating (Paul Durrant) [Orabug: 25653941]
- xen-netback: Add worse-case estimates of max_slots_needed in netbk_rx_action (Niranjan Patil) [Orabug: 25653941]
- KEYS: Remove key_type::match in favour of overriding default by match_preparse (Tim Tianyang Chen) [Orabug: 25757946] {CVE-2017-6951}
- xen/mmu: Call xen_cleanhighmap() with 4MB aligned for page tables mapping (Zhenzhong Duan) [Orabug: 26737475]
- tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0 (Wei Wang) [Orabug: 26813391] {CVE-2017-14106}
- rxrpc: Fix several cases where a padded len isn't checked in ticket decode (David Howells) [Orabug: 26880520] {CVE-2017-7482} {CVE-2017-7482}
- ocfs2: fstrim: Fix start offset of first cluster group during fstrim (Ashish Samant) [Orabug: 27099836]
- Check validity of cl_rpcclient in nfs_server_list_show (Malahal Naineni) [Orabug: 27112186]
- USB: serial: console: fix use-after-free after failed setup (Johan Hovold) [Orabug: 27206839] {CVE-2017-16525}
- ALSA: usb-audio: Check out-of-bounds access by corrupted buffer descriptor (Takashi Iwai) [Orabug: 27206934] {CVE-2017-16529}
- USB: fix out-of-bounds in usb_set_configuration (Greg Kroah-Hartman) [Orabug: 27207243] {CVE-2017-16531}
- dccp: CVE-2017-8824: use-after-free in DCCP code (Mohamed Ghannam) [Orabug: 27290308] {CVE-2017-8824}