Wily update to v4.2.8 stable release

[Kamal Mostafa]

SRU Justification

    Impact:
       The upstream process for stable tree updates is quite similar
       in scope to the Ubuntu SRU process, e.g., each patch has to
       demonstrably fix a bug, and each patch is vetted by upstream
       by originating either directly from Linus' tree or in a minimally
       backported form of that patch. The v4.2.8 upstream stable
       patch set is now available. It should be included in the Ubuntu
       kernel as well.

       git://git.kernel.org/

    TEST CASE: TBD

       The following patches are in the v4.2.8 stable release:

Linux 4.2.8
Btrfs: fix regression running delayed references when using qgroups
cobalt: fix Kconfig dependency
ALSA: hda/hdmi - apply Skylake fix-ups to Broxton display codec
ceph: fix message length computation
ocfs2: fix umask ignored issue
nfs: if we have no valid attrs, then don't declare the attribute cache valid
nfs4: start callback_ident at idr 1
debugfs: fix refcount imbalance in start_creating
nfsd: eliminate sending duplicate and repeated delegations
nfsd: serialize state seqid morphing operations
firewire: ohci: fix JMicron JMB38x IT context discovery
ext4, jbd2: ensure entering into panic after recording an error in superblock
ext4: fix potential use after free in __ext4_journal_stop
ext4 crypto: replace some BUG_ON()'s with error checks
ext4 crypto: fix memory leak in ext4_bio_write_page()
rbd: don't put snap_context twice in rbd_queue_workfn()
btrfs: fix signed overflows in btrfs_sync_file
Btrfs: fix race when listing an inode's xattrs
Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow
Btrfs: fix race leading to incorrect item deletion when dropping extents
Btrfs: fix regression when running delayed references
Btrfs: fix truncation of compressed and inlined extents
Btrfs: fix file corruption and data loss after cloning inline extents
btrfs: fix resending received snapshot with parent
via-rhine: fix VLAN receive handling regression.
net_sched: fix qdisc_tree_decrease_qlen() races
ipv6: sctp: implement sctp_v6_destroy_sock()
net/neighbour: fix crash at dumping device-agnostic proxy entries
ipv6: add complete rcu protection around np->opt
bpf, array: fix heap out-of-bounds access when updating elements
RDS: fix race condition when sending a message on unbound socket
ipv6: distinguish frag queues by device for multicast and link-local packets
broadcom: fix PHY_ID_BCM5481 entry in the id table
net: ip6mr: fix static mfc/dev leaks on table destruction
net: ipmr: fix static mfc/dev leaks on table destruction
net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds
tcp: initialize tp->copied_seq in case of cross SYN connection
tcp: fix potential huge kmalloc() calls in TCP_REPAIR
tcp: disable Fast Open on timeouts after handshake
tcp: md5: fix lockdep annotation
net: qmi_wwan: add XS Stick W100-2 from 4G Systems
snmp: Remove duplicate OUTMCAST stat increment
net: thunder: Check for driver data in nicvf_remove()
net: switchdev: fix return code of fdb_dump stub
ip_tunnel: disable preemption when updating per-cpu tstats
net/mlx4_core: Fix sleeping while holding spinlock at rem_slave_counters
sctp: translate host order to network order when setting a hmacid
packet: fix tpacket_snd max frame len
packet: infer protocol from ethernet header if unset
packet: only allow extra vlan len on ethernet devices
packet: always probe for transport header
packet: do skb_probe_transport_header when we actually have data
tools/net: Use include/uapi with __EXPORTED_HEADERS__
ipv6: Check rt->dst.from for the DST_NOCACHE route
ipv6: Check expire on DST_NOCACHE route
ipv6: Avoid creating RTF_CACHE from a rt that is not managed by fib6 tree
af-unix: passcred support for sendpage
unix: avoid use-after-free in ep_remove_wait_queue
af_unix: take receive queue lock while appending new skb
af_unix: don't append consumed skbs to sk_receive_queue
af-unix: fix use-after-free with concurrent readers while splicing

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Andy Whitcroft (apw)]

Fix released in 4.2.0-27.32