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  1. 14 May, 2020 3 commits
    • Miklos Szeredi's avatar
      proc/mounts: add cursor · 9f6c61f9
      Miklos Szeredi authored 
      If mounts are deleted after a read(2) call on /proc/self/mounts (or its
kin), the subsequent read(2) could miss a mount that comes after the
deleted one in the list.  This is because the file position is interpreted
as the number mount entries from the start of the list.

E.g. first read gets entries #0 to #9; the seq file index will be 10.  Then
entry #5 is deleted, resulting in #10 becoming #9 and #11 becoming #10,
etc...  The next read will continue from entry #10, and #9 is missed.

Solve this by adding a cursor entry for each open instance.  Taking the
global namespace_sem for write seems excessive, since we are only dealing
with a per-namespace list.  Instead add a per-namespace spinlock and use
that together with namespace_sem taken for read to protect against
concurrent modification of the mount list.  This may reduce parallelism of
is_local_mountpoint(), but it's hardly a big contention point.  We could
also use RCU freeing of cursors to make traversal not need additional
locks, if that turns out to be neceesary.

Only move the cursor once for each read (cursor is not added on open) to
minimize cacheline invalidation.  When EOF is reached, the cursor is taken
off the list, in order to prevent an excessive number of cursors due to
inactive open file descriptors.
Reported-by: default avatarKarel Zak <kzak@redhat.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
      9f6c61f9
    • Miklos Szeredi's avatar
      aio: fix async fsync creds · 530f32fc
      Miklos Szeredi authored 
      Avi Kivity reports that on fuse filesystems running in a user namespace
asyncronous fsync fails with EOVERFLOW.

The reason is that f_ops->fsync() is called with the creds of the kthread
performing aio work instead of the creds of the process originally
submitting IOCB_CMD_FSYNC.

Fuse sends the creds of the caller in the request header and it needs to
translate the uid and gid into the server's user namespace.  Since the
kthread is running in init_user_ns, the translation will fail and the
operation returns an error.

It can be argued that fsync doesn't actually need any creds, but just
zeroing out those fields in the header (as with requests that currently
don't take creds) is a backward compatibility risk.

Instead of working around this issue in fuse, solve the core of the problem
by calling the filesystem with the proper creds.
Reported-by: default avatarAvi Kivity <avi@scylladb.com>
Tested-by: default avatarGiuseppe Scrivano <gscrivan@redhat.com>
Fixes: c9582eb0 ("fuse: Fail all requests with invalid uids or gids")
Cc: stable@vger.kernel.org  # 4.18+
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      530f32fc
    • Miklos Szeredi's avatar
      vfs: allow unprivileged whiteout creation · a3c751a5
      Miklos Szeredi authored 
      Whiteouts, unlike real device node should not require privileges to create.

The general concern with device nodes is that opening them can have side
effects.  The kernel already avoids zero major (see
Documentation/admin-guide/devices.txt).  To be on the safe side the patch
explicitly forbids registering a char device with 0/0 number (see
cdev_add()).

This guarantees that a non-O_PATH open on a whiteout will fail with ENODEV;
i.e. it won't have any side effect.
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
      a3c751a5
  3. 03 May, 2020 4 commits
  5. 02 May, 2020 8 commits
    • Linus Torvalds's avatar
      Merge tag 'pm-5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 743f0573
      Linus Torvalds authored 
      Pull power management fixes from Rafael Wysocki:

 - prevent the intel_pstate driver from printing excessive diagnostic
   messages in some cases (Chris Wilson)

 - make the hibernation restore kernel freeze kernel threads as well as
   user space tasks (Dexuan Cui)

 - fix the ACPI device PM disagnostic messages to include the correct
   power state name (Kai-Heng Feng).

* tag 'pm-5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: ACPI: Output correct message on target power state
  PM: hibernate: Freeze kernel threads in software_resume()
  cpufreq: intel_pstate: Only mention the BIOS disabling turbo mode once
      743f0573
    • Rafael J. Wysocki's avatar
      Merge branches 'pm-cpufreq' and 'pm-sleep' · a5383996
      Rafael J. Wysocki authored 
      * pm-cpufreq:
  cpufreq: intel_pstate: Only mention the BIOS disabling turbo mode once

* pm-sleep:
  PM: hibernate: Freeze kernel threads in software_resume()
      a5383996
    • Linus Torvalds's avatar
      Merge tag 'iomap-5.7-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux · f66ed1eb
      Linus Torvalds authored 
      Pull iomap fix from Darrick Wong:
 "Hoist the check for an unrepresentable FIBMAP return value into
  ioctl_fibmap.

  The internal kernel function can handle 64-bit values (and is needed
  to fix a regression on ext4 + jbd2). It is only the userspace ioctl
  that is so old that it cannot deal"

* tag 'iomap-5.7-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  fibmap: Warn and return an error in case of block > INT_MAX
      f66ed1eb
    • Linus Torvalds's avatar
      Merge tag 'nfs-for-5.7-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs · 29a47f45
      Linus Torvalds authored 
      Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - fix handling of backchannel binding in BIND_CONN_TO_SESSION

  Bugfixes:
   - Fix a credential use-after-free issue in pnfs_roc()
   - Fix potential posix_acl refcnt leak in nfs3_set_acl
   - defer slow parts of rpc_free_client() to a workqueue
   - Fix an Oopsable race in __nfs_list_for_each_server()
   - Fix trace point use-after-free race
   - Regression: the RDMA client no longer responds to server disconnect
     requests
   - Fix return values of xdr_stream_encode_item_{present, absent}
   - _pnfs_return_layout() must always wait for layoutreturn completion

  Cleanups:
   - Remove unreachable error conditions"

* tag 'nfs-for-5.7-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Fix a race in __nfs_list_for_each_server()
  NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION
  SUNRPC: defer slow parts of rpc_free_client() to a workqueue.
  NFSv4: Remove unreachable error condition due to rpc_run_task()
  SUNRPC: Remove unreachable error condition
  xprtrdma: Fix use of xdr_stream_encode_item_{present, absent}
  xprtrdma: Fix trace point use-after-free race
  xprtrdma: Restore wake-up-all to rpcrdma_cm_event_handler()
  nfs: Fix potential posix_acl refcnt leak in nfs3_set_acl
  NFS/pnfs: Fix a credential use-after-free issue in pnfs_roc()
  NFS/pnfs: Ensure that _pnfs_return_layout() waits for layoutreturn completion
      29a47f45
    • Linus Torvalds's avatar
      Merge tag 'dmaengine-fix-5.7-rc4' of git://git.infradead.org/users/vkoul/slave-dma · ed6889db
      Linus Torvalds authored 
      Pull dmaengine fixes from Vinod Koul:
 "Core:
   - Documentation typo fixes
   - fix the channel indexes
   - dmatest: fixes for process hang and iterations

  Drivers:
   - hisilicon: build error fix without PCI_MSI
   - ti-k3: deadlock fix
   - uniphier-xdmac: fix for reg region
   - pch: fix data race
   - tegra: fix clock state"

* tag 'dmaengine-fix-5.7-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dmatest: Fix process hang when reading 'wait' parameter
  dmaengine: dmatest: Fix iteration non-stop logic
  dmaengine: tegra-apb: Ensure that clock is enabled during of DMA synchronization
  dmaengine: fix channel index enumeration
  dmaengine: mmp_tdma: Reset channel error on release
  dmaengine: mmp_tdma: Do not ignore slave config validation errors
  dmaengine: pch_dma.c: Avoid data race between probe and irq handler
  dt-bindings: dma: uniphier-xdmac: switch to single reg region
  include/linux/dmaengine: Typos fixes in API documentation
  dmaengine: xilinx_dma: Add missing check for empty list
  dmaengine: ti: k3-psil: fix deadlock on error path
  dmaengine: hisilicon: Fix build error without PCI_MSI
      ed6889db
    • Linus Torvalds's avatar
      Merge tag 'vfio-v5.7-rc4' of git://github.com/awilliam/linux-vfio · 690e2aba
      Linus Torvalds authored 
      Pull VFIO fixes from Alex Williamson:

 - copy_*_user validity check for new vfio_dma_rw interface (Yan Zhao)

 - Fix a potential math overflow (Yan Zhao)

 - Use follow_pfn() for calculating PFNMAPs (Sean Christopherson)

* tag 'vfio-v5.7-rc4' of git://github.com/awilliam/linux-vfio:
  vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()
  vfio: avoid possible overflow in vfio_iommu_type1_pin_pages
  vfio: checking of validity of user vaddr in vfio_dma_rw
      690e2aba
    • Linus Torvalds's avatar
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · 42eb62d4
      Linus Torvalds authored 
      Pull arm64 fix from Catalin Marinas:
 "Add -fasynchronous-unwind-tables to the vDSO CFLAGS"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: vdso: Add -fasynchronous-unwind-tables to cflags
      42eb62d4
    • Linus Torvalds's avatar
      Merge tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-block · cf018530
      Linus Torvalds authored 
      Pull io_uring fixes from Jens Axboe:

 - Fix for statx not grabbing the file table, making AT_EMPTY_PATH fail

 - Cover a few cases where async poll can handle retry, eliminating the
   need for an async thread

 - fallback request busy/free fix (Bijan)

 - syzbot reported SQPOLL thread exit fix for non-preempt (Xiaoguang)

 - Fix extra put of req for sync_file_range (Pavel)

 - Always punt splice async. We'll improve this for 5.8, but wanted to
   eliminate the inode mutex lock from the non-blocking path for 5.7
   (Pavel)

* tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-block:
  io_uring: punt splice async because of inode mutex
  io_uring: check non-sync defer_list carefully
  io_uring: fix extra put in sync_file_range()
  io_uring: use cond_resched() in io_ring_ctx_wait_and_kill()
  io_uring: use proper references for fallback_req locking
  io_uring: only force async punt if poll based retry can't handle it
  io_uring: enable poll retry for any file with ->read_iter / ->write_iter
  io_uring: statx must grab the file table for valid fd
      cf018530
  7. 01 May, 2020 19 commits
  9. 30 Apr, 2020 6 commits
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