It is very useful to be able to know whether or not get_random_bytes_wait
/ wait_for_random_bytes is going to block or not, or whether plain
get_random_bytes is going to return good randomness or bad randomness.

The particular use case is for mitigating certain attacks in WireGuard.
A handshake packet arrives and is queued up. Elsewhere a worker thread
takes items from the queue and processes them. In replying to these
items, it needs to use some random data, and it has to be good random
data. If we simply block until we can have good randomness, then it's
possible for an attacker to fill the queue up with packets waiting to be
processed. Upon realizing the queue is full, WireGuard will detect that
it's under a denial of service attack, and behave accordingly. A better
approach is just to drop incoming handshake packets if the crng is not
yet initialized.

This patch, therefore, makes that information directly accessible.
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

No need to keep preemption disabled across the whole function.

mix_pool_bytes() uses a spin_lock() to protect the pool and there are
other places like write_pool() whhich invoke mix_pool_bytes() without
disabling preemption.
credit_entropy_bits() is invoked from other places like
add_hwgenerator_randomness() without disabling preemption.

Before commit 95b709b6 ("random: drop trickle mode") the function
used __this_cpu_inc_return() which would require disabled preemption.
The preempt_disable() section was added in commit 43d5d3018c37 ("[PATCH]
random driver preempt robustness", history tree).  It was claimed that
the code relied on "vt_ioctl() being called under BKL".

Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
[bigeasy: enhance the commit message]
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

This gives the user building their own kernel (or a Linux
distribution) the option of deciding whether or not to trust the CPU's
hardware random number generator (e.g., RDRAND for x86 CPU's) as being
correctly implemented and not having a back door introduced (perhaps
courtesy of a Nation State's law enforcement or intelligence
agencies).

This will prevent getrandom(2) from blocking, if there is a
willingness to trust the CPU manufacturer.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently printing [hashed] pointers requires enough entropy to be
available.  Early in the boot sequence this may not be the case
resulting in a dummy string '(____ptrval____)' being printed.  This
makes debugging the early boot sequence difficult.  We can relax the
requirement to use cryptographically secure hashing during debugging.
This enables debugging while keeping development/production kernel
behaviour the same.

If new command line option debug_boot_weak_hash is enabled use
cryptographically insecure hashing and hash pointer value immediately.
Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NTobin C. Harding <me@tobin.cc>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently we must wait for enough entropy to become available before
hashed pointers can be printed.  We can remove this wait by using the
hw RNG if available.

Use hw RNG to get keying material.
Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Suggested-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTobin C. Harding <me@tobin.cc>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently the function get_random_bytes_arch() has return value 'void'.
If the hw RNG fails we currently fall back to using get_random_bytes().
This defeats the purpose of requesting random material from the hw RNG
in the first place.

There are currently no intree users of get_random_bytes_arch().

Only get random bytes from the hw RNG, make function return the number
of bytes retrieved from the hw RNG.
Acked-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NTobin C. Harding <me@tobin.cc>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

There are a couple of whitespace issues around the function
get_random_bytes_arch().  In preparation for patching this function
let's clean them up.
Acked-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NTobin C. Harding <me@tobin.cc>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Fedora has integrated the jitter entropy daemon to work around slow
boot problems, especially on VM's that don't support virtio-rng:

    https://bugzilla.redhat.com/show_bug.cgi?id=1572944

It's understandable why they did this, but the Jitter entropy daemon
works fundamentally on the principle: "the CPU microarchitecture is
**so** complicated and we can't figure it out, so it *must* be
random".  Yes, it uses statistical tests to "prove" it is secure, but
AES_ENCRYPT(NSA_KEY, COUNTER++) will also pass statistical tests with
flying colors.

So if RDRAND is available, mix it into entropy submitted from
userspace.  It can't hurt, and if you believe the NSA has backdoored
RDRAND, then they probably have enough details about the Intel
microarchitecture that they can reverse engineer how the Jitter
entropy daemon affects the microarchitecture, and attack its output
stream.  And if RDRAND is in fact an honest DRNG, it will immeasurably
improve on what the Jitter entropy daemon might produce.

This also provides some protection against someone who is able to read
or set the entropy seed file.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>

Pull ARM SoC fixes from Olof Johansson:
 "A small collection of fixes, sort of the usual at this point, all for
  i.MX or OMAP:

   - Enable ULPI drivers on i.MX to avoid a hang

   - Pinctrl fix for touchscreen on i.MX51 ZII RDU1

   - Fixes for ethernet clock references on am3517

   - mmc0 write protect detection fix for am335x

   - kzalloc->kcalloc conversion in an OMAP driver

   - USB metastability fix for USB on dra7

   - Fix touchscreen wakeup on am437x"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: imx_v4_v5_defconfig: Select ULPI support
  ARM: imx_v6_v7_defconfig: Select ULPI support
  ARM: dts: omap3: Fix am3517 mdio and emac clock references
  ARM: dts: am335x-bone-common: Fix mmc0 Write Protect
  bus: ti-sysc: Use 2-factor allocator arguments
  ARM: dts: dra7: Disable metastability workaround for USB2
  ARM: dts: imx51-zii-rdu1: fix touchscreen pinctrl
  ARM: dts: am437x: make edt-ft5x06 a wakeup source

Pull x86/pti updates from Thomas Gleixner:
 "Two small fixes correcting the handling of SSB mitigations on AMD
  processors"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bugs: Fix the AMD SSBD usage of the SPEC_CTRL MSR
  x86/bugs: Update when to check for the LS_CFG SSBD mitigation

Pull x86 fixes from Thomas Gleixner:

 - Prevent an out-of-bounds access in mtrr_write()

 - Break a circular dependency in the new hyperv IPI acceleration code

 - Address the build breakage related to inline functions by enforcing
   gnu_inline and explicitly bringing native_save_fl() out of line,
   which also adds a set of _ARM_ARG macros which provide 32/64bit
   safety.

 - Initialize the shadow CR4 per cpu variable before using it.

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mtrr: Don't copy out-of-bounds data in mtrr_write
  x86/hyper-v: Fix the circular dependency in IPI enlightenment
  x86/paravirt: Make native_save_fl() extern inline
  x86/asm: Add _ASM_ARG* constants for argument registers to <asm/asm.h>
  compiler-gcc.h: Add __attribute__((gnu_inline)) to all inline declarations
  x86/mm/32: Initialize the CR4 shadow before __flush_tlb_all()

Pull scheduler fixes from Thomas Gleixner:

 - The hopefully final fix for the reported race problems in
   kthread_parkme(). The previous attempt still left a hole and was
   partially wrong.

 - Plug a race in the remote tick mechanism which triggers a warning
   about updates not being done correctly. That's a false positive if
   the race condition is hit as the remote CPU is idle. Plug it by
   checking the condition again when holding run queue lock.

 - Fix a bug in the utilization estimation of a run queue which causes
   the estimation to be 0 when a run queue is throttled.

 - Advance the global expiration of the period timer when the timer is
   restarted after a idle period. Otherwise the expiry time is stale and
   the timer fires prematurely.

 - Cure the drift between the bandwidth timer and the runqueue
   accounting, which leads to bogus throttling of runqueues

 - Place the call to cpufreq_update_util() correctly so the function
   will observe the correct number of running RT tasks and not a stale
   one.

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kthread, sched/core: Fix kthread_parkme() (again...)
  sched/util_est: Fix util_est_dequeue() for throttled cfs_rq
  sched/fair: Advance global expiration when period timer is restarted
  sched/fair: Fix bandwidth timer clock drift condition
  sched/rt: Fix call to cpufreq_update_util()
  sched/nohz: Skip remote tick on idle task entirely

Pull objtool fix from Thomas Gleixner:
 "A single fix for objtool to address a bug in handling the cold
  subfunction detection for aliased functions which was added recently.
  The bug causes objtool to enter an infinite loop"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Support GCC 8 '-fnoreorder-functions'

Pull crypto fixes from Herbert Xu:

 - add missing RETs in x86 aegis/morus

 - fix build error in arm speck

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: x86 - Add missing RETs
  crypto: arm/speck - fix building in Thumb2 mode

Pull ext4 bugfixes from Ted Ts'o:
 "Bug fixes for ext4; most of which relate to vulnerabilities where a
  maliciously crafted file system image can result in a kernel OOPS or
  hang.

  At least one fix addresses an inline data bug could be triggered by
  userspace without the need of a crafted file system (although it does
  require that the inline data feature be enabled)"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: check superblock mapped prior to committing
  ext4: add more mount time checks of the superblock
  ext4: add more inode number paranoia checks
  ext4: avoid running out of journal credits when appending to an inline file
  jbd2: don't mark block as modified if the handle is out of credits
  ext4: never move the system.data xattr out of the inode body
  ext4: clear i_data in ext4_inode_info when removing inline data
  ext4: include the illegal physical block in the bad map ext4_error msg
  ext4: verify the depth of extent tree in ext4_find_extent()
  ext4: only look at the bg_flags field if it is valid
  ext4: make sure bitmaps and the inode table don't overlap with bg descriptors
  ext4: always check block group bounds in ext4_init_block_bitmap()
  ext4: always verify the magic number in xattr blocks
  ext4: add corruption check in ext4_xattr_set_entry()
  ext4: add warn_on_error mount option

Pull PCI fixes from Bjorn Helgaas:

 - Fix a use-after-free in the endpoint code (Dan Carpenter)

 - Stop defaulting CONFIG_PCIE_DW_PLAT_HOST to yes (Geert Uytterhoeven)

 - Fix an nfp regression caused by a change in how we limit the number
   of VFs we can enable (Jakub Kicinski)

 - Fix failure path cleanup issues in the new R-Car gen3 PHY support
   (Marek Vasut)

 - Fix leaks of OF nodes in faraday, xilinx-nwl, xilinx (Nicholas Mc
   Guire)

* tag 'pci-v4.18-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  nfp: stop limiting VFs to 0
  PCI/IOV: Reset total_VFs limit after detaching PF driver
  PCI: faraday: Add missing of_node_put()
  PCI: xilinx-nwl: Add missing of_node_put()
  PCI: xilinx: Add missing of_node_put()
  PCI: endpoint: Use after free in pci_epf_unregister_driver()
  PCI: controller: dwc: Do not let PCIE_DW_PLAT_HOST default to yes
  PCI: rcar: Clean up PHY init on failure
  PCI: rcar: Shut the PHY down in failpath

Pull cifs fixes from Steve French:
 "Five smb3/cifs fixes for stable (including for some leaks and memory
  overwrites) and also a few fixes for recent regressions in packet
  signing.

  Additional testing at the recent SMB3 test event, and some good work
  by Paulo and others spotted the issues fixed here. In addition to my
  xfstest runs on these, Aurelien and Stefano did additional test runs
  to verify this set"

* tag '4.18-rc3-smb3fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Fix stack out-of-bounds in smb{2,3}_create_lease_buf()
  cifs: Fix infinite loop when using hard mount option
  cifs: Fix slab-out-of-bounds in send_set_info() on SMB2 ACE setting
  cifs: Fix memory leak in smb2_set_ea()
  cifs: fix SMB1 breakage
  cifs: Fix validation of signed data in smb2
  cifs: Fix validation of signed data in smb3+
  cifs: Fix use after free of a mid_q_entry

Pull dma-mapping fix from Christoph Hellwig:
 "Revert an incorrect dma-mapping commit for 4.18-rc"

* tag 'dma-mapping-4.18-3' of git://git.infradead.org/users/hch/dma-mapping:
  Revert "iommu/intel-iommu: Enable CONFIG_DMA_DIRECT_OPS=y and clean up intel_{alloc,free}_coherent()"

Pull dmaengine fixes from Vinod Koul:
 "We have few odd driver fixes and one email update change for you this
  time:

   - Driver fixes for k3dma (off by one), pl330 (burst residue
     granularity) and omap-dma (incorrect residue_granularity)

   - Sinan's email update"

* tag 'dmaengine-fix-4.18-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: k3dma: Off by one in k3_of_dma_simple_xlate()
  dmaengine: pl330: report BURST residue granularity
  MAINTAINERS: Update email-id of Sinan Kaya
  dmaengine: ti: omap-dma: Fix OMAP1510 incorrect residue_granularity

Pull IPMI fixes from Corey Minyard:
 "A couple of small fixes: one to the BMC side of things that fixes an
  interrupt issue, and one oops fix if init fails in a certain way on
  the client driver"

* tag 'for-linus-4.18-2' of git://github.com/cminyard/linux-ipmi:
  ipmi: kcs_bmc: fix IRQ exception if the channel is not open
  ipmi: Cleanup oops on initialization failure

Pull arm64 LDFLAGS clean-up from Catalin Marinas:

 - use aarch64elf instead of aarch64linux

 - move endianness options to LDFLAGS instead from LD

 - remove no-op '-p' linker flag

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: remove no-op -p linker flag
  arm64: add endianness option to LDFLAGS instead of LD
  arm64: Use aarch64elf and aarch64elfb emulation mode variants

Don't access the provided buffer out of bounds - this can cause a kernel
out-of-bounds read when invoked through sys_splice() or other things that
use kernel_write()/__kernel_write().

Fixes: 7f8ec5a4 ("x86/mtrr: Convert to use strncpy_from_user() helper")
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180706215003.156702-1-jannh@google.com

Pull SCSI fixes from James Bottomley:
 "This is two minor bug fixes (aacraid, target) and a fix for a
  potential exploit in the way sg handles teardown"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: sg: mitigate read/write abuse
  scsi: aacraid: Fix PD performance regression over incorrect qd being set
  scsi: target: Fix truncated PR-in ReadKeys response

Pull block fixes from Jens Axboe:
 "Two minor fixes for this series:

   - add LOOP_SET_BLOCK_SIZE as compat ioctl (Evan Green)

   - drbd use-after-free fix (Lars Ellenberg)"

* tag 'for-linus-20180706' of git://git.kernel.dk/linux-block:
  loop: Add LOOP_SET_BLOCK_SIZE in compat ioctl
  drbd: fix access after free

Pull clk fixes from Stephen Boyd:
 "The usual collection of driver fixlets:

   - build cleanup/fix for the sunxi makefile that tried to save size
     but failed and prevented dead code elimination from working

   - two Davinci clk driver fixes for a typo causing build failures in
     different configurations and an error check that checks the wrong
     variable.

   - undo the DT ABI breaking imx6ul binding header shuffle that got
     merged this cycle"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  dt-bindings: clock: imx6ul: Do not change the clock definition order
  clk: davinci: fix a typo (which leads to build failures)
  clk: davinci: cfgchip: testing the wrong variable
  clk: sunxi-ng: replace lib-y with obj-y

Pull VFIO fixes from Alex Williamson:

 - Make vfio-pci IGD extensions optional via Kconfig (Alex Williamson)

 - Remove unused and soon to be removed map_atomic callback from mbochs
   sample driver, add unmap callback to avoid dmabuf leaks (Gerd
   Hoffmann)

 - Fix usage of get_user_pages_longterm() (Jason Gunthorpe)

 - Fix sample mbochs driver vm_operations_struct.fault return type
   (Souptick Joarder)

* tag 'vfio-v4.18-rc4' of git://github.com/awilliam/linux-vfio:
  sample/vfio-mdev: Change return type to vm_fault_t
  vfio: Use get_user_pages_longterm correctly
  sample/mdev/mbochs: add mbochs_kunmap_dmabuf
  sample/mdev/mbochs: remove mbochs_kmap_atomic_dmabuf
  vfio/pci: Make IGD support a configurable option

Pull s390 fixes from Martin Schwidefsky:
 "A few more changes for v4.18:

   - wire up the two new system calls io_pgetevents and rseq

   - fix a register corruption in the expolines code for machines
     without EXRL

   - drastically reduce the memory utilization of the dasd driver

   - fix reference counting for KVM page table pages"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: wire up rseq system call
  s390: wire up io_pgetevents system call
  s390/mm: fix refcount usage for 4K pgste
  s390/dasd: reduce the default queue depth and nr of hardware queues
  s390: Correct register corruption in critical section cleanup

The IPI hypercalls depend on being able to map the Linux notion of CPU ID
to the hypervisor's notion of the CPU ID. The array hv_vp_index[] provides
this mapping. Code for populating this array depends on the IPI functionality.
Break this circular dependency.

[ tglx: Use a proper define instead of '-1' with a u32 variable as pointed
  	out by Vitaly ]

Fixes: 68bb7bfb ("X86/Hyper-V: Enable IPI enlightenments")
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NMichael Kelley <mikelley@microsoft.com>
Cc: gregkh@linuxfoundation.org
Cc: devel@linuxdriverproject.org
Cc: olaf@aepfle.de
Cc: apw@canonical.com
Cc: jasowang@redhat.com
Cc: hpa@zytor.com
Cc: sthemmin@microsoft.com
Cc: Michael.H.Kelley@microsoft.com
Cc: vkuznets@redhat.com
Link: https://lkml.kernel.org/r/20180703230155.15160-1-kys@linuxonhyperv.com

Pull drm fixes from Dave Airlie:
 "This is the drm fixes for rc4.

  It's a bit larger than I'd like but the exynos cleanups are pretty
  mechanical, and I'd rather have them in sooner rather than later so we
  can avoid too much conflicts around them. The non-mechanincal exynos
  changes are mostly fixes for new feature recently introduced.

  Apart from the exynos updates, we have:

  i915:
   - GVT and GGTT mapping fixes

  amdgpu:
   - fix HDMI2.0 4K@60 Hz regression
   - Hotplug fixes for dual-GPU laptops to make power management better
   - misc vega12 bios fixes, a race fix and some typos.

  sii8620 bridge:
   - small fixes around mode setting

  core:
   - use kvzalloc to allocate blob property memory"

* tag 'drm-fixes-2018-07-06' of git://anongit.freedesktop.org/drm/drm: (34 commits)
  drm/amd/display: add a check for display depth validity
  drm/amd/display: adding ycbcr420 pixel encoding for hdmi
  drm/udl: fix display corruption of the last line
  drm/bridge/sii8620: Fix link mode selection
  drm/bridge/sii8620: Fix display of packed pixel modes
  drm/bridge/sii8620: Send AVI infoframe in all MHL versions
  drm/amdgpu: fix user fence write race condition
  drm/i915: Try GGTT mmapping whole object as partial
  drm/amdgpu/pm: fix display count in non-DC path
  drm/amdgpu: fix swapped emit_ib_size in vce3
  drm: Use kvzalloc for allocating blob property memory
  drm/i915/gvt: changed DDI mode emulation type
  drm/i915/gvt: fix a bug of partially write ggtt enties
  drm/exynos: Replace drm_dev_unref with drm_dev_put
  drm/exynos: Replace drm_gem_object_unreference_unlocked with put function
  drm/exynos: Replace drm_framebuffer_{un/reference} with put,get functions
  drm/exynos: ipp: use correct enum type
  drm/exynos: decon5433: Fix WINCONx reset value
  drm/exynos: decon5433: Fix per-plane global alpha for XRGB modes
  drm/exynos: fimc: Use real buffer width for configuring the hardware
  ...

Pull tracing fixes and cleanups from Steven Rostedt:
 "While cleaning out my INBOX, I found a few patches that were lost in
  the noise. These are minor bug fixes and clean ups. Those include:

   - avoid a string overflow

   - code that didn't match the comment (but should)

   - a small code optimization (use of a conditional)

   - quiet printf warnings

   - nuke unused code

   - fix function graph interrupt annotation"

* tag 'trace-v4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix missing return symbol in function_graph output
  ftrace: Nuke clear_ftrace_function
  tracing: Use __printf markup to silence compiler
  tracing: Optimize trace_buffer_iter() logic
  tracing: Make create_filter() code match the comments
  tracing: Avoid string overflow

Merge tag 'exynos-drm-fixes-for-v4.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-fixes

Fixups
- Fix several problems to IPPv2 merged to mainline recentely.
  . An align problem of width size that IPP driver incorrectly
    calculated the real buffer size.
  . Horizontal and vertical flip problem.
  . Per-plane global alpha for XRGB modes.
  . Incorrect variant of the YUV modes.
- Fix plane overlapping problem.
  . The stange order of overlapping planes on XRGB modes
    by setting global alpha value to maximum value.

Cleanup
- Rename a enum type, drm_ipp_size_id, to one specific to Exynos,
  drm_exynos_ipp_limit_type.
- Replace {un/reference} with {put,get} functions.
  . it replaces several reference/unreference functions with Linux
    kernel nameing standard.
Signed-off-by: NDave Airlie <airlied@redhat.com>

Link: https://patchwork.freedesktop.org/patch/msgid/1530512041-21392-1-git-send-email-inki.dae@samsung.com

- Fix an HDMI 2.0 4k@60 regression
- Hotplug fixes for PX/HG laptops
- Fixes for vbios changes in vega12
- Fix a race in the user fence code
- Fix a couple of misc typos
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180705155206.2752-1-alexander.deucher@amd.com

Merge tag 'drm-intel-fixes-2018-07-05' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

A couple of GVT fixes, and a GGTT mmapping fix.
Signed-off-by: NDave Airlie <airlied@redhat.com>

Link: https://patchwork.freedesktop.org/patch/msgid/8736wxq35t.fsf@intel.com

Fixes for v4.18-rc4:
- A few small fixes for the sii8620 bridge.
- Allocate blob property memory using kvzalloc instead of kmalloc.
Signed-off-by: NDave Airlie <airlied@redhat.com>

Link: https://patchwork.freedesktop.org/patch/msgid/4267636e-bb7c-8f69-eeff-12e045b3e7e1@linux.intel.com

Merge tag 'omap-for-v4.18/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

Fixes for omap for v4.18-rc cycle

Few dts fixes for regressions for various SoCs and
devices for touchscreen wake, dra7 USB quirk, pinmux
for beaglebone mmc, and emac clock.

Also included is a change for ti-sysc to use kcalloc
that Kees wanted to get into v4.18 as that's the last
one he wanted to fix for improved defense against
allocation overflows.

* tag 'omap-for-v4.18/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: dts: omap3: Fix am3517 mdio and emac clock references
  ARM: dts: am335x-bone-common: Fix mmc0 Write Protect
  bus: ti-sysc: Use 2-factor allocator arguments
  ARM: dts: dra7: Disable metastability workaround for USB2
  ARM: dts: am437x: make edt-ft5x06 a wakeup source
Signed-off-by: NOlof Johansson <olof@lixom.net>

sgid directories have special semantics, making newly created files in
the directory belong to the group of the directory, and newly created
subdirectories will also become sgid.  This is historically used for
group-shared directories.

But group directories writable by non-group members should not imply
that such non-group members can magically join the group, so make sure
to clear the sgid bit on non-directories for non-members (but remember
that sgid without group execute means "mandatory locking", just to
confuse things even more).
Reported-by: NJann Horn <jannh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Revert "iommu/intel-iommu: Enable CONFIG_DMA_DIRECT_OPS=y and clean up intel_{alloc,free}_coherent()"

This commit may cause a less than required dma mask to be used for
some allocations, which apparently leads to module load failures for
iwlwifi sometimes.

This reverts commit d657c5c7.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reported-by: NFabio Coatti <fabio.coatti@gmail.com>
Tested-by: NFabio Coatti <fabio.coatti@gmail.com>

smb{2,3}_create_lease_buf() store a lease key in the lease
context for later usage on a lease break.

In most paths, the key is currently sourced from data that
happens to be on the stack near local variables for oplock in
SMB2_open() callers, e.g. from open_shroot(), whereas
smb2_open_file() properly allocates space on its stack for it.

The address of those local variables holding the oplock is then
passed to create_lease_buf handlers via SMB2_open(), and 16
bytes near oplock are used. This causes a stack out-of-bounds
access as reported by KASAN on SMB2.1 and SMB3 mounts (first
out-of-bounds access is shown here):

[  111.528823] BUG: KASAN: stack-out-of-bounds in smb3_create_lease_buf+0x399/0x3b0 [cifs]
[  111.530815] Read of size 8 at addr ffff88010829f249 by task mount.cifs/985
[  111.532838] CPU: 3 PID: 985 Comm: mount.cifs Not tainted 4.18.0-rc3+ #91
[  111.534656] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[  111.536838] Call Trace:
[  111.537528]  dump_stack+0xc2/0x16b
[  111.540890]  print_address_description+0x6a/0x270
[  111.542185]  kasan_report+0x258/0x380
[  111.544701]  smb3_create_lease_buf+0x399/0x3b0 [cifs]
[  111.546134]  SMB2_open+0x1ef8/0x4b70 [cifs]
[  111.575883]  open_shroot+0x339/0x550 [cifs]
[  111.591969]  smb3_qfs_tcon+0x32c/0x1e60 [cifs]
[  111.617405]  cifs_mount+0x4f3/0x2fc0 [cifs]
[  111.674332]  cifs_smb3_do_mount+0x263/0xf10 [cifs]
[  111.677915]  mount_fs+0x55/0x2b0
[  111.679504]  vfs_kern_mount.part.22+0xaa/0x430
[  111.684511]  do_mount+0xc40/0x2660
[  111.698301]  ksys_mount+0x80/0xd0
[  111.701541]  do_syscall_64+0x14e/0x4b0
[  111.711807]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  111.713665] RIP: 0033:0x7f372385b5fa
[  111.715311] Code: 48 8b 0d 99 78 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 66 78 2c 00 f7 d8 64 89 01 48
[  111.720330] RSP: 002b:00007ffff27049d8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
[  111.722601] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f372385b5fa
[  111.724842] RDX: 000055c2ecdc73b2 RSI: 000055c2ecdc73f9 RDI: 00007ffff270580f
[  111.727083] RBP: 00007ffff2705804 R08: 000055c2ee976060 R09: 0000000000001000
[  111.729319] R10: 0000000000000000 R11: 0000000000000206 R12: 00007f3723f4d000
[  111.731615] R13: 000055c2ee976060 R14: 00007f3723f4f90f R15: 0000000000000000

[  111.735448] The buggy address belongs to the page:
[  111.737420] page:ffffea000420a7c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[  111.739890] flags: 0x17ffffc0000000()
[  111.741750] raw: 0017ffffc0000000 0000000000000000 dead000000000200 0000000000000000
[  111.744216] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[  111.746679] page dumped because: kasan: bad access detected

[  111.750482] Memory state around the buggy address:
[  111.752562]  ffff88010829f100: 00 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00
[  111.754991]  ffff88010829f180: 00 00 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00
[  111.757401] >ffff88010829f200: 00 00 00 00 00 f1 f1 f1 f1 01 f2 f2 f2 f2 f2 f2
[  111.759801]                                               ^
[  111.762034]  ffff88010829f280: f2 02 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00
[  111.764486]  ffff88010829f300: f2 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  111.766913] ==================================================================

Lease keys are however already generated and stored in fid data
on open and create paths: pass them down to the lease context
creation handlers and use them.
Suggested-by: NAurélien Aptel <aaptel@suse.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Fixes: b8c32dbb ("CIFS: Request SMB2.1 leases")
Signed-off-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

For every request we send, whether it is SMB1 or SMB2+, we attempt to
reconnect tcon (cifs_reconnect_tcon or smb2_reconnect) before carrying
out the request.

So, while server->tcpStatus != CifsNeedReconnect, we wait for the
reconnection to succeed on wait_event_interruptible_timeout(). If it
returns, that means that either the condition was evaluated to true, or
timeout elapsed, or it was interrupted by a signal.

Since we're not handling the case where the process woke up due to a
received signal (-ERESTARTSYS), the next call to
wait_event_interruptible_timeout() will _always_ fail and we end up
looping forever inside either cifs_reconnect_tcon() or smb2_reconnect().

Here's an example of how to trigger that:

$ mount.cifs //foo/share /mnt/test -o
username=foo,password=foo,vers=1.0,hard

(break connection to server before executing bellow cmd)
$ stat -f /mnt/test & sleep 140
[1] 2511

$ ps -aux -q 2511
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root      2511  0.0  0.0  12892  1008 pts/0    S    12:24   0:00 stat -f
/mnt/test

$ kill -9 2511

(wait for a while; process is stuck in the kernel)
$ ps -aux -q 2511
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root      2511 83.2  0.0  12892  1008 pts/0    R    12:24  30:01 stat -f
/mnt/test

By using 'hard' mount point means that cifs.ko will keep retrying
indefinitely, however we must allow the process to be killed otherwise
it would hang the system.
Signed-off-by: NPaulo Alcantara <palcantara@suse.de>
Cc: stable@vger.kernel.org
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>