Merge more fixes from Andrew Morton:
 "5 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  swap_readpage(): avoid blk_wake_io_task() if !synchronous
  devres: allow const resource arguments
  mm/vmscan.c: prevent useless kswapd loops
  fs/userfaultfd.c: disable irqs for fault_pending and event locks
  mm/page_alloc.c: fix regression with deferred struct page init

Pull ARM SoC fixes from Olof Johansson:
 "Likely our final small batch of fixes for 5.2:

   - Some fixes for USB on davinci, regressions were due to the recent
     conversion of the OCHI driver to use GPIO regulators

   - A fixup of kconfig dependencies for a TI irq controller

   - A switch of armada-38x to avoid dropped characters on uart, caused
     by switch of base inherited platform description earlier this year"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  ARM: davinci: da830-evm: fix GPIO lookup for OHCI
  ARM: davinci: omapl138-hawk: add missing regulator constraints for OHCI
  ARM: davinci: da830-evm: add missing regulator constraints for OHCI
  soc: ti: fix irq-ti-sci link error
  ARM: dts: armada-xp-98dx3236: Switch to armada-38x-uart serial node

Pull dax fix from Dan Williams:
 "A single dax fix that has been soaking awaiting other fixes under
  discussion to join it. As it is getting late in the cycle lets proceed
  with this fix and save follow-on changes for post-v5.3-rc1.

   - Fix xarray entry association for mixed mappings"

* tag 'dax-fix-5.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: Fix xarray entry association for mixed mappings

Pull do_move_mount() fix from Al Viro:
 "Regression fix"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: move_mount: reject moving kernel internal mounts

swap_readpage() sets waiter = bio->bi_private even if synchronous = F,
this means that the caller can get the spurious wakeup after return.

This can be fatal if blk_wake_io_task() does
set_current_state(TASK_RUNNING) after the caller does
set_special_state(), in the worst case the kernel can crash in
do_task_dead().

Link: http://lkml.kernel.org/r/20190704160301.GA5956@redhat.com
Fixes: 0619317f ("block: add polled wakeup task helper")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Qian Cai <cai@lca.pw>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

devm_ioremap_resource() does not currently take 'const' arguments, which
results in a warning from the first driver trying to do it anyway:

  drivers/gpio/gpio-amd-fch.c: In function 'amd_fch_gpio_probe':
  drivers/gpio/gpio-amd-fch.c:171:49: error: passing argument 2 of 'devm_ioremap_resource' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
    priv->base = devm_ioremap_resource(&pdev->dev, &amd_fch_gpio_iores);
                                                   ^~~~~~~~~~~~~~~~~~~

Change the prototype to allow it, as there is no real reason not to.

Link: http://lkml.kernel.org/r/20190628150049.1108048-1-arnd@arndb.de
Fixes: 9bb2e0452508 ("gpio: amd: Make resource struct const")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In production we have noticed hard lockups on large machines running
large jobs due to kswaps hoarding lru lock within isolate_lru_pages when
sc->reclaim_idx is 0 which is a small zone.  The lru was couple hundred
GiBs and the condition (page_zonenum(page) > sc->reclaim_idx) in
isolate_lru_pages() was basically skipping GiBs of pages while holding
the LRU spinlock with interrupt disabled.

On further inspection, it seems like there are two issues:

(1) If kswapd on the return from balance_pgdat() could not sleep (i.e.
    node is still unbalanced), the classzone_idx is unintentionally set
    to 0 and the whole reclaim cycle of kswapd will try to reclaim only
    the lowest and smallest zone while traversing the whole memory.

(2) Fundamentally isolate_lru_pages() is really bad when the
    allocation has woken kswapd for a smaller zone on a very large machine
    running very large jobs.  It can hoard the LRU spinlock while skipping
    over 100s of GiBs of pages.

This patch only fixes (1).  (2) needs a more fundamental solution.  To
fix (1), in the kswapd context, if pgdat->kswapd_classzone_idx is
invalid use the classzone_idx of the previous kswapd loop otherwise use
the one the waker has requested.

Link: http://lkml.kernel.org/r/20190701201847.251028-1-shakeelb@google.com
Fixes: e716f2eb ("mm, vmscan: prevent kswapd sleeping prematurely due to mismatched classzone_idx")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When IOCB_CMD_POLL is used on a userfaultfd, aio_poll() disables IRQs
and takes kioctx::ctx_lock, then userfaultfd_ctx::fd_wqh.lock.

This may have to wait for userfaultfd_ctx::fd_wqh.lock to be released by
userfaultfd_ctx_read(), which in turn can be waiting for
userfaultfd_ctx::fault_pending_wqh.lock or
userfaultfd_ctx::event_wqh.lock.

But elsewhere the fault_pending_wqh and event_wqh locks are taken with
IRQs enabled.  Since the IRQ handler may take kioctx::ctx_lock, lockdep
reports that a deadlock is possible.

Fix it by always disabling IRQs when taking the fault_pending_wqh and
event_wqh locks.

Commit ae62c16e ("userfaultfd: disable irqs when taking the
waitqueue lock") didn't fix this because it only accounted for the
fd_wqh lock, not the other locks nested inside it.

Link: http://lkml.kernel.org/r/20190627075004.21259-1-ebiggers@kernel.org
Fixes: bfe4037e ("aio: implement IOCB_CMD_POLL")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reported-by: syzbot+fab6de82892b6b9c6191@syzkaller.appspotmail.com
Reported-by: syzbot+53c0b767f7ca0dc0c451@syzkaller.appspotmail.com
Reported-by: syzbot+a3accb352f9c22041cfa@syzkaller.appspotmail.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>	[4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 0e56acae ("mm: initialize MAX_ORDER_NR_PAGES at a time
instead of doing larger sections") is causing a regression on some
systems when the kernel is booted as Xen dom0.

The system will just hang in early boot.

Reason is an endless loop in get_page_from_freelist() in case the first
zone looked at has no free memory.  deferred_grow_zone() is always
returning true due to the following code snipplet:

  /* If the zone is empty somebody else may have cleared out the zone */
  if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
                                           first_deferred_pfn)) {
          pgdat->first_deferred_pfn = ULONG_MAX;
          pgdat_resize_unlock(pgdat, &flags);
          return true;
  }

This in turn results in the loop as get_page_from_freelist() is assuming
forward progress can be made by doing some more struct page
initialization.

Link: http://lkml.kernel.org/r/20190620160821.4210-1-jgross@suse.com
Fixes: 0e56acae ("mm: initialize MAX_ORDER_NR_PAGES at a time instead of doing larger sections")
Signed-off-by: Juergen Gross <jgross@suse.com>
Suggested-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Acked-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull sound fixes from Takashi Iwai:
 "Here are a collection of small fixes for:

   - A race with ASoC HD-audio registration

   - LINE6 usb-audio memory overwrite by malformed descriptor

   - FireWire MIDI handling

   - Missing cast for bit shifts in a few USB-audio quirks

   - The wrong function calls in minor OSS sequencer code paths

   - A couple of HD-audio quirks"

* tag 'sound-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: line6: Fix write on zero-sized buffer
  ALSA: hda: Fix widget_mutex incomplete protection
  ALSA: firewire-lib/fireworks: fix miss detection of received MIDI messages
  ALSA: seq: fix incorrect order of dest_client/dest_ports arguments
  ALSA: hda/realtek - Change front mic location for Lenovo M710q
  ALSA: usb-audio: fix sign unintended sign extension on left shifts
  ALSA: hda/realtek: Add quirks for several Clevo notebook barebones

Fix two issues:

When called for PTRACE_TRACEME, ptrace_link() would obtain an RCU
reference to the parent's objective credentials, then give that pointer
to get_cred().  However, the object lifetime rules for things like
struct cred do not permit unconditionally turning an RCU reference into
a stable reference.

PTRACE_TRACEME records the parent's credentials as if the parent was
acting as the subject, but that's not the case.  If a malicious
unprivileged child uses PTRACE_TRACEME and the parent is privileged, and
at a later point, the parent process becomes attacker-controlled
(because it drops privileges and calls execve()), the attacker ends up
with control over two processes with a privileged ptrace relationship,
which can be abused to ptrace a suid binary and obtain root privileges.

Fix both of these by always recording the credentials of the process
that is requesting the creation of the ptrace relationship:
current_cred() can't change under us, and current is the proper subject
for access control.

This change is theoretically userspace-visible, but I am not aware of
any code that it will actually break.

Fixes: 64b875f7 ("ptrace: Capture the ptracer's creds not PT_PTRACE_CAP")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull tracing fixes from Steven Rostedt:
 "This includes three fixes:

   - Fix a deadlock from a previous fix to keep module loading and
     function tracing text modifications from stepping on each other
     (this has a few patches to help document the issue in comments)

   - Fix a crash when the snapshot buffer gets out of sync with the main
     ring buffer

   - Fix a memory leak when reading the memory logs"

* tag 'trace-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/x86: Anotate text_mutex split between ftrace_arch_code_modify_post_process() and ftrace_arch_code_modify_prepare()
  tracing/snapshot: Resize spare buffer if size changed
  tracing: Fix memory leak in tracing_err_log_open()
  ftrace/x86: Add a comment to why we take text_mutex in ftrace_arch_code_modify_prepare()
  ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()

Pull GPIO fix from Linus Walleij:
 "A single fixup for the SPI CS gpios that regressed in the current
  kernel cycle"

* tag 'gpio-v5.2-4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio/spi: Fix spi-gpio regression on active high CS

Fix minimum encryption key size check so that HCI_MIN_ENC_KEY_SIZE is
also allowed as stated in the comment.

This bug caused connection problems with devices having maximum
encryption key size of 7 octets (56-bit).

Fixes: 693cd8ce ("Bluetooth: Fix regression with minimum encryption key size alignment")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203997Signed-off-by: Matias Karhumaa <matias.karhumaa@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull cifs fix from Steve French:
 "SMB3 fix (for stable as well) for crash mishandling one of the Windows
  reparse point symlink tags"

* tag '5.2-rc6-smb3-fix' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix crash querying symlinks stored as reparse-points

Pull pidfd fork() fix from Christian Brauner:
 "A single small fix for copy_process() in kernel/fork.c:

  With Al's removal of ksys_close() from cleanup paths in copy_process()
  a bug was introduced. When anon_inode_getfile() failed the cleanup was
  correctly performed but the error code was not propagated to callers
  of copy_process() causing them to operate on a nonsensical pointer.

  The fix is a simple on-liner which makes sure that a proper negative
  error code is returned from copy_process().

  syzkaller has also verified that the bug is not reproducible with this
  fix"

* tag 'for-linus-20190701' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  fork: return proper negative error code

Pull arm64 fixes from Will Deacon:
 "Fix a build failure with the LLVM linker and a module allocation
  failure when KASLR is active:

   - Fix module allocation when running with KASLR enabled

   - Fix broken build due to bug in LLVM linker (ld.lld)"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/efi: Mark __efistub_stext_offset as an absolute symbol explicitly
  arm64: kaslr: keep modules inside module region when KASAN is enabled

Merge tag 'davinci-fixes-for-v5.2-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci into arm/fixes

This set of patches fixes regressions introduced in v5.2 kernel when DA8xx
OHCI driver was converted over to use GPIO regulators.

* tag 'davinci-fixes-for-v5.2-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci:
  ARM: davinci: da830-evm: fix GPIO lookup for OHCI
  ARM: davinci: omapl138-hawk: add missing regulator constraints for OHCI
  ARM: davinci: da830-evm: add missing regulator constraints for OHCI
  + Linux 5.2-rc7
Signed-off-by: Olof Johansson <olof@lixom.net>

I ran into an intriguing bug caused by
commit ""spi: gpio: Don't request CS GPIO in DT use-case"
affecting all SPI GPIO devices with an active high
chip select line.

The commit switches the CS gpio handling over to the GPIO
core, which will parse and handle "cs-gpios" from the OF
node without even calling down to the driver to get the
job done.

However the GPIO core handles the standard bindings in
Documentation/devicetree/bindings/spi/spi-controller.yaml
that specifies that active high CS needs to be specified
using "spi-cs-high" in the DT node.

The code in drivers/spi/spi-gpio.c never respected this
and never tried to inspect subnodes to see if they contained
"spi-cs-high" like the gpiolib OF quirks does. Instead the
only way to get an active high CS was to tag it in the
device tree using the flags cell such as
cs-gpios = <&gpio 4 GPIO_ACTIVE_HIGH>;

This alters the quirks to not inspect the subnodes of SPI
masters on "spi-gpio" for the standard attribute "spi-cs-high",
making old device trees work as expected.

This semantic is a bit ambigous, but just allowing the
flags on the GPIO descriptor to modify polarity is what
the kernel at large mostly uses so let's encourage that.

Fixes: 249e2632 ("spi: gpio: Don't request CS GPIO in DT use-case")
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-spi@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

ftrace/x86: Anotate text_mutex split between ftrace_arch_code_modify_post_process() and ftrace_arch_code_modify_prepare()

ftrace_arch_code_modify_prepare() is acquiring text_mutex, while the
corresponding release is happening in ftrace_arch_code_modify_post_process().

This has already been documented in the code, but let's also make the fact
that this is intentional clear to the semantic analysis tools such as sparse.

Link: http://lkml.kernel.org/r/nycvar.YFH.7.76.1906292321170.27227@cbobk.fhfr.pm

Fixes: 39611265 ("ftrace/x86: Add a comment to why we take text_mutex in ftrace_arch_code_modify_prepare()")
Fixes: d5b844a2 ("ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

LINE6 drivers allocate the buffers based on the value returned from
usb_maxpacket() calls.  The manipulated device may return zero for
this, and this results in the kmalloc() with zero size (and it may
succeed) while the other part of the driver code writes the packet
data with the fixed size -- which eventually overwrites.

This patch adds a simple sanity check for the invalid buffer size for
avoiding that problem.

Reported-by: syzbot+219f00fb49874dcaea17@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The fixed regulator driver doesn't specify any con_id for gpio lookup
so it must be NULL in the table entry.

Fixes: 274e4c33 ("ARM: davinci: da830-evm: add a fixed regulator for ohci-da8xx")
Cc: stable@vger.kernel.org
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

We need to enable status changes for the fixed power supply for the USB
controller.

Fixes: 1d272894 ("ARM: davinci: omapl138-hawk: add a fixed regulator for ohci-da8xx")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

We need to enable status changes for the fixed power supply for the USB
controller.

Fixes: 274e4c33 ("ARM: davinci: da830-evm: add a fixed regulator for ohci-da8xx")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

The irqchip driver depends on the SoC specific driver, but we want
to be able to compile-test it elsewhere:

WARNING: unmet direct dependencies detected for TI_SCI_INTA_MSI_DOMAIN
  Depends on [n]: SOC_TI [=n]
  Selected by [y]:
  - TI_SCI_INTA_IRQCHIP [=y] && TI_SCI_PROTOCOL [=y]

drivers/irqchip/irq-ti-sci-inta.o: In function `ti_sci_inta_irq_domain_probe':
irq-ti-sci-inta.c:(.text+0x204): undefined reference to `ti_sci_inta_msi_create_irq_domain'

Rearrange the Kconfig and Makefile so we build the soc driver whenever
its users are there, regardless of the SOC_TI option.

Fixes: 49b32315 ("soc: ti: Add MSI domain bus support for Interrupt Aggregator")
Fixes: f011df61 ("irqchip/ti-sci-inta: Add msi domain support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

mvebu fixes for 5.2 (part 2)

Use the armada-38x-uart compatible strings for Armada XP 98dx3236 SoCs
in order to not loose character anymore.

* tag 'mvebu-fixes-5.2-2' of git://git.infradead.org/linux-mvebu:
  ARM: dts: armada-xp-98dx3236: Switch to armada-38x-uart serial node
Signed-off-by: Olof Johansson <olof@lixom.net>

The widget_mutex was introduced to serialize callers to
hda_widget_sysfs_{re}init. However, its protection of the sysfs widget array
is incomplete. For example, it is acquired around the call to
hda_widget_sysfs_reinit(), which actually creates the new array, but isn't
still acquired when codec->num_nodes and codec->start_nid is updated. So
the lock ensures one thread sets up the new array at a time, but doesn't
ensure which thread's value will end up in codec->num_nodes. If a larger
num_nodes wins but a smaller array was set up, the next call to
refresh_widgets() will touch free memory as it iterates over codec->num_nodes
that aren't there.

The widget_lock really protects both the tree as well as codec->num_nodes,
start_nid, and end_nid, so make sure it's held across that update. It should
also be held during snd_hdac_get_sub_nodes(), so that a very old read from that
function doesn't end up clobbering a later update.

Fixes: ed180abb ("ALSA: hda: Fix race between creating and refreshing sysfs entries")
Signed-off-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

In IEC 61883-6, 8 MIDI data streams are multiplexed into single
MIDI conformant data channel. The index of stream is calculated by
modulo 8 of the value of data block counter.

In fireworks, the value of data block counter in CIP header has a quirk
with firmware version v5.0.0, v5.7.3 and v5.8.0. This brings ALSA
IEC 61883-1/6 packet streaming engine to miss detection of MIDI
messages.

This commit fixes the miss detection to modify the value of data block
counter for the modulo calculation.

For maintainers, this bug exists since a commit 18f5ed36 ("ALSA:
fireworks/firewire-lib: add support for recent firmware quirk") in Linux
kernel v4.2. There're many changes since the commit.  This fix can be
backported to Linux kernel v4.4 or later. I tagged a base commit to the
backport for your convenience.

Besides, my work for Linux kernel v5.3 brings heavy code refactoring and
some structure members are renamed in 'sound/firewire/amdtp-stream.h'.
The content of this patch brings conflict when merging -rc tree with
this patch and the latest tree. I request maintainers to solve the
conflict to replace 'tx_first_dbc' with 'ctx_data.tx.first_dbc'.

Fixes: df075fee ("ALSA: firewire-lib: complete AM824 data block processing layer")
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sys_move_mount() crashes by dereferencing the pointer MNT_NS_INTERNAL,
a.k.a. ERR_PTR(-EINVAL), if the old mount is specified by fd for a
kernel object with an internal mount, such as a pipe or memfd.

Fix it by checking for this case and returning -EINVAL.

[AV: what we want is is_mounted(); use that instead of making the
condition even more convoluted]

Reproducer:

    #include <unistd.h>

    #define __NR_move_mount         429
    #define MOVE_MOUNT_F_EMPTY_PATH 0x00000004

    int main()
    {
    	int fds[2];

    	pipe(fds);
        syscall(__NR_move_mount, fds[0], "", -1, "/", MOVE_MOUNT_F_EMPTY_PATH);
    }

Reported-by: syzbot+6004acbaa1893ad013f0@syzkaller.appspotmail.com
Fixes: 2db154b3 ("vfs: syscall: Add move_mount(2) to move mounts around")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Make sure to return a proper negative error code from copy_process()
when anon_inode_getfile() fails with CLONE_PIDFD.
Otherwise _do_fork() will not detect an error and get_task_pid() will
operator on a nonsensical pointer:

R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
R13: 00007ffc15fbb0ff R14: 00007ff07e47e9c0 R15: 0000000000000000
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7990 Comm: syz-executor290 Not tainted 5.2.0-rc6+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline]
RIP: 0010:get_task_pid+0xe1/0x210 kernel/pid.c:372
Code: 89 ff e8 62 27 5f 00 49 8b 07 44 89 f1 4c 8d bc c8 90 01 00 00 eb 0c
e8 0d fe 25 00 49 81 c7 38 05 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74
08 4c 89 ff e8 31 27 5f 00 4d 8b 37 e8 f9 47 12 00
RSP: 0018:ffff88808a4a7d78 EFLAGS: 00010203
RAX: 00000000000000a7 RBX: dffffc0000000000 RCX: ffff888088180600
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88808a4a7d90 R08: ffffffff814fb3a8 R09: ffffed1015d66bf8
R10: ffffed1015d66bf8 R11: 1ffff11015d66bf7 R12: 0000000000041ffc
R13: 1ffff11011494fbc R14: 0000000000000000 R15: 000000000000053d
FS:  00007ff07e47e700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004b5100 CR3: 0000000094df2000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  _do_fork+0x1b9/0x5f0 kernel/fork.c:2360
  __do_sys_clone kernel/fork.c:2454 [inline]
  __se_sys_clone kernel/fork.c:2448 [inline]
  __x64_sys_clone+0xc1/0xd0 kernel/fork.c:2448
  do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: https://lore.kernel.org/lkml/000000000000e0dc0d058c9e7142@google.com
Reported-and-tested-by: syzbot+002e636502bc4b64eb5c@syzkaller.appspotmail.com
Fixes: 6fd2fe49 ("copy_process(): don't use ksys_close() on cleanups")
Cc: Jann Horn <jannh@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <christian@brauner.io>

Pull powerpc fix from Michael Ellerman:
 "One fix for a regression in my commit adding KUAP (Kernel User Access
  Prevention) on Radix, which incorrectly touched the AMR in the early
  machine check handler.

  Thanks to Nicholas Piggin"

* tag 'powerpc-5.2-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/exception: Fix machine check early corrupting AMR

Pull SMP fixes from Thomas Gleixner:
 "Two small changes for the cpu hotplug code:

   - Prevent out of bounds access which actually might crash the machine
     caused by a missing bounds check in the fail injection code

   - Warn about unsupported migitation mode command line arguments to
     make people aware that they typoed the paramater. Not necessarily a
     fix but quite some people tripped over that"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Fix out-of-bounds read when setting fail state
  cpu/speculation: Warn on unsupported mitigations= parameter

Pull x86 fixes from Ingo Molnar:
 "Misc fixes all over the place:

   - might_sleep() atomicity fix in the microcode loader

   - resctrl boundary condition fix

   - APIC arithmethics bug fix for frequencies >= 4.2 GHz

   - three 5-level paging crash fixes

   - two speculation fixes

   - a perf/stacktrace fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/unwind/orc: Fall back to using frame pointers for generated code
  perf/x86: Always store regs->ip in perf_callchain_kernel()
  x86/speculation: Allow guests to use SSBD even if host does not
  x86/mm: Handle physical-virtual alignment mismatch in phys_p4d_init()
  x86/boot/64: Add missing fixup_pointer() for next_early_pgt access
  x86/boot/64: Fix crash if kernel image crosses page table boundary
  x86/apic: Fix integer overflow on 10 bit left shift of cpu_khz
  x86/resctrl: Prevent possible overrun during bitmap operations
  x86/microcode: Fix the microcode load on CPU hotplug for real

Pull perf fixes from Ingo Molnar:
 "Various fixes, most of them related to bugs perf fuzzing found in the
  x86 code"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/regs: Use PERF_REG_EXTENDED_MASK
  perf/x86: Remove pmu->pebs_no_xmm_regs
  perf/x86: Clean up PEBS_XMM_REGS
  perf/x86/regs: Check reserved bits
  perf/x86: Disable extended registers for non-supported PMUs
  perf/ioctl: Add check for the sample_period value
  perf/core: Fix perf_sample_regs_user() mm check

Pull irq fixes from Ingo Molnar:
 "Diverse irqchip driver fixes"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Fix command queue pointer comparison bug
  irqchip/mips-gic: Use the correct local interrupt map registers
  irqchip/ti-sci-inta: Fix kernel crash if irq_create_fwspec_mapping fail
  irqchip/irq-csky-mpintc: Support auto irq deliver to all cpus

Pull EFI fixes from Ingo Molnar:
 "Four fixes:
   - fix a kexec crash on arm64
   - fix a reboot crash on some Android platforms
   - future-proof the code for upcoming ACPI 6.2 changes
   - fix a build warning on x86"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efibc: Replace variable set function in notifier call
  x86/efi: fix a -Wtype-limits compilation warning
  efi/bgrt: Drop BGRT status field reserved bits check
  efi/memreserve: deal with memreserve entries in unmapped memory

Pull power management fix from Rafael Wysocki:
 "Avoid skipping bus-level PCI power management during system resume for
  PCIe ports left in D0 during the preceding suspend transition on
  platforms where the power states of those ports can change out of the
  PCI layer's control"

* tag 'pm-5.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PCI: PM: Avoid skipping bus-level PM on platforms without ACPI

Pull XArray fixes from Matthew Wilcox:

 - Account XArray nodes for the page cache to the appropriate cgroup
   (Johannes Weiner)

 - Fix idr_get_next() when called under the RCU lock (Matthew Wilcox)

 - Add a test for xa_insert() (Matthew Wilcox)

* tag 'xarray-5.2-rc6' of git://git.infradead.org/users/willy/linux-dax:
  XArray tests: Add check_insert
  idr: Fix idr_get_next race with idr_remove
  mm: fix page cache convergence regression

Merge misc fixes from Andrew Morton:
 "15 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  linux/kernel.h: fix overflow for DIV_ROUND_UP_ULL
  mm, swap: fix THP swap out
  fork,memcg: alloc_thread_stack_node needs to set tsk->stack
  MAINTAINERS: add CLANG/LLVM BUILD SUPPORT info
  mm/vmalloc.c: avoid bogus -Wmaybe-uninitialized warning
  mm/page_idle.c: fix oops because end_pfn is larger than max_pfn
  initramfs: fix populate_initrd_image() section mismatch
  mm/oom_kill.c: fix uninitialized oc->constraint
  mm: hugetlb: soft-offline: dissolve_free_huge_page() return zero on !PageHuge
  mm: soft-offline: return -EBUSY if set_hwpoison_free_buddy_page() fails
  signal: remove the wrong signal_pending() check in restore_user_sigmask()
  fs/binfmt_flat.c: make load_flat_shared_library() work
  mm/mempolicy.c: fix an incorrect rebind node in mpol_rebind_nodemask
  fs/proc/array.c: allow reporting eip/esp for all coredumping threads
  mm/dev_pfn: exclude MEMORY_DEVICE_PRIVATE while computing virtual address