Xenial update to 4.4.151 stable release

[Stefan Bader]

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 a mainline/stable Linux tree or
       a minimally backported form of that patch. The 4.4.151 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 from the 4.4.151 stable release shall be applied:
* dccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart()
* l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cache
* llc: use refcount_inc_not_zero() for llc_sap_find()
* net_sched: Fix missing res info when create new tc_index filter
* vsock: split dwork to avoid reinitializations
* net_sched: fix NULL pointer dereference when delete tcindex filter
* ALSA: hda - Sleep for 10ms after entering D3 on Conexant codecs
* ALSA: hda - Turn CX8200 into D3 as well upon reboot
* ALSA: vx222: Fix invalid endian conversions
* ALSA: virmidi: Fix too long output trigger loop
* ALSA: cs5535audio: Fix invalid endian conversion
* ALSA: hda: Correct Asrock B85M-ITX power_save blacklist entry
* ALSA: memalloc: Don't exceed over the requested size
* ALSA: vxpocket: Fix invalid endian conversions
* USB: serial: sierra: fix potential deadlock at close
* USB: option: add support for DW5821e
* ACPI: save NVS memory for Lenovo G50-45
* ACPI / PM: save NVS memory for ASUS 1025C laptop
* serial: 8250_dw: always set baud rate in dw8250_set_termios
* Bluetooth: avoid killing an already killed socket
* isdn: Disable IIOCDBGVAR
* Linux 4.4.151

[Stefan Bader (smb)]

Skipped "x86/mm: Simplify p[g4um]d_page() macros" because we already picked that up as prerequisite for L1TF.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.4.0-138.164

---------------
linux (4.4.0-138.164) xenial; urgency=medium

  * linux: 4.4.0-138.164 -proposed tracker (LP: #1795582)

  * Linux 4.4.155 stable release build is broken on ppc64 (LP: #1795662)
    - powerpc/fadump: Return error when fadump registration fails

  * Kernel hang on drive pull caused by regression introduced by commit
    287922eb0b18 (LP: #1791790)
    - block: Fix a race between blk_cleanup_queue() and timeout handling

  * qeth: use vzalloc for QUERY OAT buffer (LP: #1793086)
    - s390/qeth: use vzalloc for QUERY OAT buffer

  * Page leaking in cachefiles_read_backing_file while vmscan is active
    (LP: #1793430)
    - SAUCE: cachefiles: Page leaking in cachefiles_read_backing_file while vmscan
      is active

  * Bugfix for handling of shadow doorbell buffer (LP: #1788222)
    - nvme-pci: add a memory barrier to nvme_dbbuf_update_and_check_event

  * Xenial update to 4.4.155 stable release (LP: #1792419)
    - net: 6lowpan: fix reserved space for single frames
    - net: mac802154: tx: expand tailroom if necessary
    - 9p/net: Fix zero-copy path in the 9p virtio transport
    - net: lan78xx: Fix misplaced tasklet_schedule() call
    - spi: davinci: fix a NULL pointer dereference
    - drm/i915/userptr: reject zero user_size
    - powerpc/fadump: handle crash memory ranges array index overflow
    - powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.
    - fs/9p/xattr.c: catch the error of p9_client_clunk when setting xattr failed
    - 9p/virtio: fix off-by-one error in sg list bounds check
    - net/9p/client.c: version pointer uninitialized
    - net/9p/trans_fd.c: fix race-condition by flushing workqueue before the
      kfree()
    - dm cache metadata: save in-core policy_hint_size to on-disk superblock
    - iio: ad9523: Fix displayed phase
    - iio: ad9523: Fix return value for ad952x_store()
    - vmw_balloon: fix inflation of 64-bit GFNs
    - vmw_balloon: do not use 2MB without batching
    - vmw_balloon: VMCI_DOORBELL_SET does not check status
    - vmw_balloon: fix VMCI use when balloon built into kernel
    - tracing: Do not call start/stop() functions when tracing_on does not change
    - tracing/blktrace: Fix to allow setting same value
    - kthread, tracing: Don't expose half-written comm when creating kthreads
    - uprobes: Use synchronize_rcu() not synchronize_sched()
    - 9p: fix multiple NULL-pointer-dereferences
    - PM / sleep: wakeup: Fix build error caused by missing SRCU support
    - pnfs/blocklayout: off by one in bl_map_stripe()
    - ARM: tegra: Fix Tegra30 Cardhu PCA954x reset
    - mm/tlb: Remove tlb_remove_table() non-concurrent condition
    - iommu/vt-d: Add definitions for PFSID
    - iommu/vt-d: Fix dev iotlb pfsid use
    - osf_getdomainname(): use copy_to_user()
    - sys: don't hold uts_sem while accessing userspace memory
    - userns: move user access out of the mutex
    - ubifs: Fix memory leak in lprobs self-check
    - Revert "UBIFS: Fix potential integer overflow in allocation"
    - ubifs: Check data node size before truncate
    - ubifs: Fix synced_i_size calculation for xattr inodes
    - pwm: ti...