The devm_memremap() function doesn't return NULL, it returns error
pointers.

Fixes: 9a10c7e6 ("drm/simpledrm: Add support for system memory framebuffers")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/Y9JHzImRcUaa0mi1@kili
(cherry picked from commit e566507b)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Due to holidays we started -next with more -fixes in-flight than
usual, and people have been asking where they are. Backmerge to get
things better in sync.

Conflicts:
- Tiny conflict in drm_fbdev_generic.c between variable rename and
  missing error handling that got added.
- Conflict in drm_fb_helper.c between the added call to vgaswitcheroo
  in drm_fb_helper_single_fb_probe and a refactor patch that extracted
  lots of helpers and incidentally removed the dev local variable.
  Readd it to make things compile.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

amd-drm-next-6.3-2023-01-27:

amdgpu:
- GC11 fixes
- SMU13 fixes
- Freesync fixes
- DP MST fixes
- DP MST code rework and cleanup
- AV1 fixes for VCN4
- DCN 3.2.x fixes
- PSR fixes
- DML optimizations
- DC link code rework
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230127225917.2419162-1-alexander.deucher@amd.com

drm/tegra: Changes for v6.3-rc1

This set of changes includes a rework of the custom syncpoint interrupt
code to take better advantage of existing DRM/KMS infrastructure.

There's also various bits of cleanup and fixes included.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230127170119.495943-1-thierry.reding@gmail.com

Merge tag 'drm-next-20230127' of git://git.kernel.org/pub/scm/linux/kernel/git/pinchartl/linux into drm-next

Renesas R-Car DU fixes and improvements
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/Y9QCw3SkHm6k1bwJ@pendragon.ideasonboard.com

drm/i915 feature pull #2 v6.3:

Features and functionality:
- Enable HF-EEODB by switching HDMI, DP and LVDS to use struct drm_edid (Jani)
- Start using unversioned DMC firmware paths for new platforms (Gustavo)

Refactoring and cleanups:
- ELD refactor: Stop using hardware buffer, precompute ELD, and wire up ELD in
  the state checker (Ville)
- Use generics for debugfs device parameters (Jani)
- DSB refactoring and fixes (Ville)
- Header refactoring, add new intel_display_limits.h (Jani)
- Split out GMCH code to a new file (Jani)
- Split out vblank code to a new file (Jani)
- i915_drv.h and struct drm_i915_private cleanups (Jani)
- Simplify FBC and DRRS debug attributes (Deepak R Varma)
- Remove some single-use macros (Rodrigo)

Fixes:
- Fix scaler limits for display versions 12 and 13 (Luca)
- Fix plane source size check for zero height (Drew Davenport)
- Implement PSR2 selective fetch workaround (Jouni)
- Expand a PSR workaound to more platforms and pipes (Jouni)
- Expand an HDMI infoframe workaround to all MTL steppings (Jouni)
- Enable PIPEDMC whenever its corresponding pipe is enabled (Imre)

Merges:
- Backmerge drm-next (Jani)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/87tu0c44gv.fsf@intel.com

Merge tag 'drm-habanalabs-next-2023-01-26' of https://git.kernel.org/pub/scm/linux/kernel/git/ogabbay/linux into drm-next

This tag contains habanalabs driver and accel changes for v6.3:

- Moved the driver to the accel subsystem. Currently only the files were
  moved (including the uapi file which was also renamed). This doesn't
  include registering to the accel subsystem. This will probably be only
  in the next kernel version.

- In case of decoder error (axi error) in Gaudi2, we can now find the exact
  IP that initiated the erroneous transaction and print the details for
  better debug.

- Add more trace events. We now can trace mmio transactions and communication
  with the preboot firmware.

- Add to Gaudi2 support for abrupt reset that is done by the firmware. This
  was support so far only for Gaudi1.

- Add uAPI to flush memory transactions (to the device memory). This is
  needed by the communications library in case of doing p2p with a host NIC
  which access our HBM directly through the PCI BAR.

- Add uAPI to pass-through a request from user-space to firmware and get the
  result back to user-space. This will allow the driver code to avoid the
  need to add new packet (in the communication channel with the firmware) for
  every new request type.

- Remove the option to export dma-buf by memory allocation handle in our uAPI.
  This was planned for Gaudi2 but was never used. Instead, we will do export
  by memory address (same as Gaudi1). In addition, we added the option to
  specify an offset to the address. This is needed in Gaudi2 because there
  the user allocates the entire HBM in one allocation, but would like to
  export only small part of it.

- Multiple bug fixes, refactors and small optimizations.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Oded Gabbay <ogabbay@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230126213317.GA1520525@ogabbay-vm-u20.habana-labs.com

drm-misc-next for v6.3:

UAPI Changes:

Cross-subsystem Changes:

Core Changes:

 * fbdev-helper: Streamline code in generic fbdev and its helpers

 * TTM: Fixes plus their reverts

Driver Changes:

 * accel/ivpu: Typo fixes

 * i915: TTM-related fixes

 * nouveau: Remove unused return value from disable helper
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/Y9I2nOzHxTxPeTjg@linux-uq9g

Pull irq fix from Borislav Petkov:

 - Cleanup the firmware node for the new IRQ MSI domain properly, to
   avoid leaking memory

* tag 'irq_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/msi: Free the fwnode created by msi_create_device_irq_domain()

Pull x86 fixes from Borislav Petkov:

 - Start checking for -mindirect-branch-cs-prefix clang support too now
   that LLVM 16 will support it

 - Fix a NULL ptr deref when suspending with Xen PV

 - Have a SEV-SNP guest check explicitly for features enabled by the
   hypervisor and fail gracefully if some are unsupported by the guest
   instead of failing in a non-obvious and hard-to-debug way

 - Fix a MSI descriptor leakage under Xen

 - Mark Xen's MSI domain as supporting MSI-X

 - Prevent legacy PIC interrupts from being resent in software by
   marking them level triggered, as they should be, which lead to a NULL
   ptr deref

* tag 'x86_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Move '-mindirect-branch-cs-prefix' out of GCC-only block
  acpi: Fix suspend with Xen PV
  x86/sev: Add SEV-SNP guest feature negotiation support
  x86/pci/xen: Fixup fallout from the PCI/MSI overhaul
  x86/pci/xen: Set MSI_FLAG_PCI_MSIX support in Xen MSI domain
  x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL

Pull input fixes from Dmitry Torokhov:

 - touchpads on HP 15-* laptops switched back to PS/2 emulation mode

 - a quirk for Clevo PCX0DX/TUXEDO XP1511 to make sure keyboard is
   responding after resume

* tag 'input-for-v6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: i8042 - add Clevo PCX0DX to i8042 quirk table
  Revert "Input: synaptics - switch touchpad on HP Laptop 15-da3001TU to RMI mode"

Pull cxl fixes from Dan Williams:
 "A couple of fixes for bugs introduced during the merge window. One is
  a regression, the other was a bug in the CXL AER handler:

   - Fix a crash regression due to module load order of cxl_pmem.ko

   - Fix wrong register offset read in CXL AER handling path"

* tag 'cxl-fixes-for-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
  cxl/pmem: Fix nvdimm unregistration when cxl_pmem driver is absent
  cxl: fix cxl_report_and_clear() RAS UE addr mis-assignment

This reverts commit 7efc3b72.

We have got openSUSE reports (Link 1) for 6.1 kernel with khugepaged
stalling CPU for long periods of time.  Investigation of tracepoint data
shows that compaction is stuck in repeating fast_find_migrateblock()
based migrate page isolation, and then fails to migrate all isolated
pages.

Commit 7efc3b72 ("mm/compaction: fix set skip in fast_find_migrateblock")
was suspected as it was merged in 6.1 and in theory can indeed remove a
termination condition for fast_find_migrateblock() under certain
conditions, as it removes a place that always marks a scanned pageblock
from being re-scanned.  There are other such places, but those can be
skipped under certain conditions, which seems to match the tracepoint
data.

Testing of revert also appears to have resolved the issue, thus revert
the commit until a more robust solution for the original problem is
developed.

It's also likely this will fix qemu stalls with 6.1 kernel reported in
Link 2, but that is not yet confirmed.

Link: https://bugzilla.suse.com/show_bug.cgi?id=1206848
Link: https://lore.kernel.org/kvm/b8017e09-f336-3035-8344-c549086c2340@kernel.org/
Link: https://lore.kernel.org/lkml/20230125134434.18017-1-mgorman@techsingularity.net/
Fixes: 7efc3b72 ("mm/compaction: fix set skip in fast_find_migrateblock")
Cc: <stable@vger.kernel.org>
Tested-by: Pedro Falcato <pedro.falcato@gmail.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Joe found another DT file that shouldn't be executable, and that
frustrated me enough that I went hunting with this script:

    git ls-files -s |
        grep '^100755' |
        cut -f2 |
        xargs grep -L '^#!'

and that found another file that shouldn't have been marked executable
either, despite being in the scripts directory.

Maybe these two are the last ones at least for now.  But I'm sure we'll
be back in a few years, fixing things up again.

Fixes: 8c6789f4 ("ASoC: dt-bindings: Add Everest ES8326 audio CODEC")
Fixes: 4d8e5cd2 ("locking/atomics: Fix scripts/atomic/ script permissions")
Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ksmbd server fixes from Steve French:
 "Four smb3 server fixes, all also for stable:

   - fix for signing bug

   - fix to more strictly check packet length

   - add a max connections parm to limit simultaneous connections

   - fix error message flood that can occur with newer Samba xattr
     format"

* tag '6.2-rc5-ksmbd-server-fixes' of git://git.samba.org/ksmbd:
  ksmbd: downgrade ndr version error message to debug
  ksmbd: limit pdu length size according to connection status
  ksmbd: do not sign response to session request for guest login
  ksmbd: add max connections parameter

Pull cifs fix from Steve French:
 "Fix for reconnect oops in smbdirect (RDMA), also is marked for stable"

* tag '6.2-rc5-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Fix oops due to uncleared server->smbd_conn in reconnect

Pull block fixes from Jens Axboe:
 "Minor tweaks for this release:

   - NVMe pull request via Christoph:
        - Flush initial scan_work for async probe (Keith Busch)
        - Fix passthrough csi check (Keith Busch)
        - Fix nvme-fc initialization order (Ross Lagerwall)

   - Fix for tearing down non-started device in ublk (Ming)"

* tag 'block-6.2-2023-01-27' of git://git.kernel.dk/linux:
  block: ublk: move ublk_chr_class destroying after devices are removed
  nvme: fix passthrough csi check
  nvme-pci: flush initial scan_work for async probe
  nvme-fc: fix initialization order

Pull io_uring fixes from Jens Axboe:
 "Two small fixes for this release:

   - Sanitize how async prep is done for drain requests, so we ensure
     that it always gets done (Dylan)

   - A ring provided buffer recycling fix for multishot receive (me)"

* tag 'io_uring-6.2-2023-01-27' of git://git.kernel.dk/linux:
  io_uring: always prep_async for drain requests
  io_uring/net: cache provided buffer group value for multishot receives

Pull hardening fixes from Kees Cook:

 - Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

 - Reorganize gcc-plugin includes for GCC 13

 - Silence bcache memcpy run-time false positive warnings

* tag 'hardening-v6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  bcache: Silence memcpy() run-time false positive warnings
  gcc-plugins: Reorganize gimple includes for GCC 13
  kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

Pull tracing fixes from Steven Rostedt:

 - Fix filter memory leak by calling ftrace_free_filter()

 - Initialize trace_printk() earlier so that ftrace_dump_on_oops shows
   data on early crashes.

 - Update the outdated instructions in scripts/tracing/ftrace-bisect.sh

 - Add lockdep_is_held() to fix lockdep warning

 - Add allocation failure check in create_hist_field()

 - Don't initialize pointer that gets set right away in enabled_monitors_write()

 - Update MAINTAINER entries

 - Fix help messages in Kconfigs

 - Fix kernel-doc header for update_preds()

* tag 'trace-v6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  bootconfig: Update MAINTAINERS file to add tree and mailing list
  rv: remove redundant initialization of pointer ptr
  ftrace: Maintain samples/ftrace
  tracing/filter: fix kernel-doc warnings
  lib: Kconfig: fix spellos
  trace_events_hist: add check for return value of 'create_hist_field'
  tracing/osnoise: Use built-in RCU list checking
  tracing: Kconfig: Fix spelling/grammar/punctuation
  ftrace/scripts: Update the instructions for ftrace-bisect.sh
  tracing: Make sure trace_printk() can output as soon as it can be used
  ftrace: Export ftrace_free_filter() to modules

This fixes the build here locally on my 32-bit arm build.
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit f439a959)
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Pull i2c fixes from Wolfram Sang:
 "A bunch of driver fixes with a tiny bit of new IDs"

* tag 'i2c-for-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: rk3x: fix a bunch of kernel-doc warnings
  i2c: axxia: use 'struct' for kernel-doc notation
  dt-bindings: i2c: renesas,rzv2m: Fix SoC specific string
  i2c: mxs: suppress probe-deferral error message
  i2c: designware-pci: Add new PCI IDs for AMD NAVI GPU
  i2c: designware: Fix unbalanced suspended flag
  i2c: designware: use casting of u64 in clock multiplication to avoid overflow

Pull gpio fixes from Bartosz Golaszewski:

 - fix the -c option in the gpio-event-mode user-space example program

 - fix the irq number translation in gpio-ep93xx and make its irqchip
   immutable

 - add a missing spin_unlock in error path in gpio-mxc

 - fix a suspend breakage on System76 and Lenovo Gen2a introduced in
   GPIO ACPI

* tag 'gpio-fixes-for-v6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  tools: gpio: fix -c option of gpio-event-mon
  gpio: ep93xx: remove unused variable
  gpio: ep93xx: Make irqchip immutable
  gpio: ep93xx: Fix port F hwirq numbers in handler
  gpio: mxc: Unlock on error path in mxc_flip_edge()
  gpiolib-acpi: Don't set GPIOs for wakeup in S3 mode

Merge tag 'regulator-fix-v6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator fix from Mark Brown:
 "A fix for the DT binding documentation which dropped a property when
  being converted to YAML format causing spurious errors validating
  device trees for platforms using the device"

* tag 'regulator-fix-v6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: dt-bindings: samsung,s2mps14: add lost samsung,ext-control-gpios

Pull overlayfs fixes from Miklos Szeredi:
 "Fix two bugs, a recent one introduced in the last cycle, and an older
  one from v5.11"

* tag 'ovl-fixes-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fail on invalid uid/gid mapping at copy up
  ovl: fix tmpfile leak

Pull drm fixes from Dave Airlie:
 "Fairly small this week as well, i915 has a memory leak fix and some
  minor changes, and amdgpu has some MST fixes, and some other minor
  ones:

  drm:
   - DP MST kref fix
   - fb_helper: check return value

  i915:
   - Fix BSC default context for Meteor Lake
   - Fix selftest-scheduler's modify_type
   - memory leak fix

  amdgpu:
   - GC11.x fixes
   - SMU13.0.0 fix
   - Freesync video fix
   - DP MST fixes
   - build fix"

* tag 'drm-fixes-2023-01-27' of git://anongit.freedesktop.org/drm/drm:
  amdgpu: fix build on non-DCN platforms.
  drm/amd/display: Fix timing not changning when freesync video is enabled
  drm/display/dp_mst: Correct the kref of port.
  drm/amdgpu/display/mst: update mst_mgr relevant variable when long HPD
  drm/amdgpu/display/mst: limit payload to be updated one by one
  drm/amdgpu/display/mst: Fix mst_state->pbn_div and slot count assignments
  drm/amdgpu: declare firmware for new MES 11.0.4
  drm/amdgpu: enable imu firmware for GC 11.0.4
  drm/amd/pm: add missing AllowIHInterrupt message mapping for SMU13.0.0
  drm/amdgpu: remove unconditional trap enable on add gfx11 queues
  drm/fb-helper: Use a per-driver FB deferred I/O handler
  drm/fb-helper: Check fb_deferred_io_init() return value
  drm/i915/selftest: fix intel_selftest_modify_policy argument types
  drm/i915/mtl: Fix bcs default context
  drm/i915: Fix a memory leak with reused mmap_offset
  drm/drm_vma_manager: Add drm_vma_node_allow_once()

Pull ACPI fixes from Rafael Wysocki:
 "Add ACPI backlight handling quirks for 3 machines (Hans de Goede)"

* tag 'acpi-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: video: Add backlight=native DMI quirk for Asus U46E
  ACPI: video: Add backlight=native DMI quirk for HP EliteBook 8460p
  ACPI: video: Add backlight=native DMI quirk for HP Pavilion g6-1d80nr

Pull thermal control fixes from Rafael Wysocki:
 "Add locking to the Intel int340x thermal control driver to prevent its
  thermal zone callbacks from racing with firmware-induced thermal trip
  point updates (Srinivas Pandruvada, Rafael Wysocki)"

* tag 'thermal-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal: intel: int340x: Add locking to int340x_thermal_get_trip_type()
  thermal: intel: int340x: Protect trip temperature from concurrent updates

Pull arm64 fix from Will Deacon:

 - Fix event counting regression in Arm CMN PMU driver due to broken
   optimisation

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  Partially revert "perf/arm-cmn: Optimise DTC counter accesses"

Pull RISC-V fixes from Palmer Dabbelt:

 - A few DT bindings fixes to more closely align the ISA string
   requirements between the bindings and the ISA manual.

 - A handful of build error/warning fixes.

 - A fix to move init_cpu_topology() later in the boot flow, so it can
   allocate memory.

 - The IRC channel is now in the MAINTAINERS file, so it's easier to
   find.

* tag 'riscv-for-linus-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Move call to init_cpu_topology() to later initialization stage
  riscv/kprobe: Fix instruction simulation of JALR
  riscv: fix -Wundef warning for CONFIG_RISCV_BOOT_SPINWAIT
  MAINTAINERS: add an IRC entry for RISC-V
  RISC-V: fix compile error from deduplicated __ALTERNATIVE_CFG_2
  dt-bindings: riscv: fix single letter canonical order
  dt-bindings: riscv: fix underscore requirement for multi-letter extensions

Pull ARM fixes from Russell King:

 - fix nommu assignment build warning

 - fix -Wundef preprocessor warning

 - reduce __thumb2__ definitions for crypto files that require it

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 9287/1: Reduce __thumb2__ definition to crypto files that require it
  ARM: 9284/1: include <asm/pgtable.h> from proc-macros.S to fix -Wundef warnings
  ARM: 9280/1: mm: fix warning on phys_addr_t to void pointer assignment

Merge tag 'linux-kselftest-fixes-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest fixes from Shuah Khan:
 "A single fix to a amd-pstate test Makefile bug that deletes source
  files during make clean run"

* tag 'linux-kselftest-fixes-6.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: amd-pstate: Don't delete source files via Makefile

Use the newly implemented tegra_dev_iommu_get_stream_id() helper to
encapsulate and centralize the IOMMU stream ID access.
Signed-off-by: Thierry Reding <treding@nvidia.com>

Use the newly implemented tegra_dev_iommu_get_stream_id() helper to
encapsulate and centralize the IOMMU stream ID access.
Signed-off-by: Thierry Reding <treding@nvidia.com>

Use the newly implemented tegra_dev_iommu_get_stream_id() helper to
encapsulate and centralize the IOMMU stream ID access.
Signed-off-by: Thierry Reding <treding@nvidia.com>

Use the newly implemented tegra_dev_iommu_get_stream_id() helper to
encapsulate and centralize the IOMMU stream ID access.
Signed-off-by: Thierry Reding <treding@nvidia.com>

If st_uid/st_gid doesn't have a mapping in the mounter's user_ns, then
copy-up should fail, just like it would fail if the mounter task was doing
the copy using "cp -a".

There's a corner case where the "cp -a" would succeed but copy up fail: if
there's a mapping of the invalid uid/gid (65534 by default) in the user
namespace.  This is because stat(2) will return this value if the mapping
doesn't exist in the current user_ns and "cp -a" will in turn be able to
create a file with this uid/gid.

This behavior would be inconsistent with POSIX ACL's, which return -1 for
invalid uid/gid which result in a failed copy.

For consistency and simplicity fail the copy of the st_uid/st_gid are
invalid.

Fixes: 459c7c56 ("ovl: unprivieged mounts")
Cc: <stable@vger.kernel.org> # v5.11
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Seth Forshee <sforshee@kernel.org>

Missed an error cleanup.

Reported-by: syzbot+fd749a7ea127a84e0ffd@syzkaller.appspotmail.com
Fixes: 2b1a7746 ("ovl: use vfs_tmpfile_open() helper")
Cc: <stable@vger.kernel.org> # v6.1
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Drain requests all go through io_drain_req, which has a quick exit in case
there is nothing pending (ie the drain is not useful). In that case it can
run the issue the request immediately.

However for safety it queues it through task work.
The problem is that in this case the request is run asynchronously, but
the async work has not been prepared through io_req_prep_async.

This has not been a problem up to now, as the task work always would run
before returning to userspace, and so the user would not have a chance to
race with it.

However - with IORING_SETUP_DEFER_TASKRUN - this is no longer the case and
the work might be defered, giving userspace a chance to change data being
referred to in the request.

Instead _always_ prep_async for drain requests, which is simpler anyway
and removes this issue.

Cc: stable@vger.kernel.org
Fixes: c0e0d6ba ("io_uring: add IORING_SETUP_DEFER_TASKRUN")
Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20230127105911.2420061-1-dylany@meta.comSigned-off-by: Jens Axboe <axboe@kernel.dk>