commit cb095afd44768bf495894b9ad063bd078e4bb201 upstream.

In preparation for having additional actions during init/exit, this moves
the init/exit into platform.c, centralizing the logic to make call outs
to the fs init/exit.
Signed-off-by: NKees Cook <keescook@chromium.org>
Tested-by: NGuenter Roeck <groeck@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0d52154bb0a700abb459a2cbce0a30fc2549b67e upstream.

When failing from creating cache jbd2_inode_cache, we will destroy the
previously created cache jbd2_handle_cache twice.  This patch fixes
this by moving each cache initialization/destruction to its own
separate, individual function.
Signed-off-by: NChengguang Xu <cgxu519@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 2c1d0e3631e5732dba98ef49ac0bec1388776793 upstream.

Handling of aborted journal is a special code path different from
standard ext4_error() one and it can call panic() as well. Commit
1dc1097ff60e ("ext4: avoid panic during forced reboot") forgot to update
this path so fix that omission.

Fixes: 1dc1097ff60e ("ext4: avoid panic during forced reboot")
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 5.1
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 08fc98a4d6424af66eb3ac4e2cedd2fc927ed436 upstream.

The buffer_head (frames[0].bh) and it's corresping page can be
potentially free'd once brelse() is done inside the for loop
but before the for loop exits in dx_release(). It can be free'd
in another context, when the page cache is flushed via
drop_caches_sysctl_handler(). This results into below data abort
when accessing info->indirect_levels in dx_release().

Unable to handle kernel paging request at virtual address ffffffc17ac3e01e
Call trace:
 dx_release+0x70/0x90
 ext4_htree_fill_tree+0x2d4/0x300
 ext4_readdir+0x244/0x6f8
 iterate_dir+0xbc/0x160
 SyS_getdents64+0x94/0x174
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 57a0da28ced8707cb9f79f071a016b9d005caf5a upstream.

Unaligned AIO must be serialized because the zeroing of partial blocks
of unaligned AIO can result in data corruption in case it's overlapping
another in flight IO.

Currently we wait for all unwritten extents before we submit unaligned
AIO which protects data in case of unaligned AIO is following overlapping
IO. However if a unaligned AIO is followed by overlapping aligned AIO we
can still end up corrupting data.

To fix this, we must make sure that the unaligned AIO is the only IO in
flight by waiting for unwritten extents conversion not just before the
IO submission, but right after it as well.

This problem can be reproduced by xfstest generic/538
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 592acbf16821288ecdc4192c47e3774a4c48bb64 upstream.

This commit zeroes out the unused memory region in the buffer_head
corresponding to the extent metablock after writing the extent header
and the corresponding extent node entries.

This is done to prevent random uninitialized data from getting into
the filesystem when the extent block is synced.

This fixes CVE-2019-11833.
Signed-off-by: NSriram Rajagopalan <sriramr@arista.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ec084de929e419e51bcdafaafe567d9e7d0273b7 upstream.

synchronize_rcu() didn't wait for call_rcu() callbacks, so inode wb
switch may not go to the workqueue after synchronize_rcu().  Thus
previous scheduled switches was not finished even flushing the
workqueue, which will cause a NULL pointer dereferenced followed below.

  VFS: Busy inodes after unmount of vdd. Self-destruct in 5 seconds.  Have a nice day...
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000278
    evict+0xb3/0x180
    iput+0x1b0/0x230
    inode_switch_wbs_work_fn+0x3c0/0x6a0
    worker_thread+0x4e/0x490
    ? process_one_work+0x410/0x410
    kthread+0xe6/0x100
    ret_from_fork+0x39/0x50

Replace the synchronize_rcu() call with a rcu_barrier() to wait for all
pending callbacks to finish.  And inc isw_nr_in_flight after call_rcu()
in inode_switch_wbs() to make more sense.

Link: http://lkml.kernel.org/r/20190429024108.54150-1-jiufei.xue@linux.alibaba.comSigned-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Acked-by: NTejun Heo <tj@kernel.org>
Suggested-by: NTejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bfc61c36260ca990937539cd648ede3cd749bc10 upstream.

When finding out which inodes have references on a particular extent, done
by backref.c:iterate_extent_inodes(), from the BTRFS_IOC_LOGICAL_INO (both
v1 and v2) ioctl and from scrub we use the transaction join API to grab a
reference on the currently running transaction, since in order to give
accurate results we need to inspect the delayed references of the currently
running transaction.

However, if there is currently no running transaction, the join operation
will create a new transaction. This is inefficient as the transaction will
eventually be committed, doing unnecessary IO and introducing a potential
point of failure that will lead to a transaction abort due to -ENOSPC, as
recently reported [1].

That's because the join, creates the transaction but does not reserve any
space, so when attempting to update the root item of the root passed to
btrfs_join_transaction(), during the transaction commit, we can end up
failling with -ENOSPC. Users of a join operation are supposed to actually
do some filesystem changes and reserve space by some means, which is not
the case of iterate_extent_inodes(), it is a read-only operation for all
contextes from which it is called.

The reported [1] -ENOSPC failure stack trace is the following:

 heisenberg kernel: ------------[ cut here ]------------
 heisenberg kernel: BTRFS: Transaction aborted (error -28)
 heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs]
(...)
 heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2
 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018
 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs]
(...)
 heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286
 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006
 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0
 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007
 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078
 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068
 heisenberg kernel: FS:  0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000
 heisenberg kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0
 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 heisenberg kernel: Call Trace:
 heisenberg kernel:  commit_fs_roots+0x166/0x1d0 [btrfs]
 heisenberg kernel:  ? _cond_resched+0x15/0x30
 heisenberg kernel:  ? btrfs_run_delayed_refs+0xac/0x180 [btrfs]
 heisenberg kernel:  btrfs_commit_transaction+0x2bd/0x870 [btrfs]
 heisenberg kernel:  ? start_transaction+0x9d/0x3f0 [btrfs]
 heisenberg kernel:  transaction_kthread+0x147/0x180 [btrfs]
 heisenberg kernel:  ? btrfs_cleanup_transaction+0x530/0x530 [btrfs]
 heisenberg kernel:  kthread+0x112/0x130
 heisenberg kernel:  ? kthread_bind+0x30/0x30
 heisenberg kernel:  ret_from_fork+0x35/0x40
 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]---

So fix that by using the attach API, which does not create a transaction
when there is currently no running transaction.

[1] https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/Reported-by: NZygo Blaxell <ce3g8jdj@umail.furryterror.org>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 03628cdbc64db6262e50d0357960a4e9562676a1 upstream.

During fiemap, for regular extents (non inline) we need to check if they
are shared and if they are, set the shared bit. Checking if an extent is
shared requires checking the delayed references of the currently running
transaction, since some reference might have not yet hit the extent tree
and be only in the in-memory delayed references.

However we were using a transaction join for this, which creates a new
transaction when there is no transaction currently running. That means
that two more potential failures can happen: creating the transaction and
committing it. Further, if no write activity is currently happening in the
system, and fiemap calls keep being done, we end up creating and
committing transactions that do nothing.

In some extreme cases this can result in the commit of the transaction
created by fiemap to fail with ENOSPC when updating the root item of a
subvolume tree because a join does not reserve any space, leading to a
trace like the following:

 heisenberg kernel: ------------[ cut here ]------------
 heisenberg kernel: BTRFS: Transaction aborted (error -28)
 heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs]
(...)
 heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2
 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018
 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs]
(...)
 heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286
 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006
 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0
 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007
 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078
 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068
 heisenberg kernel: FS:  0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000
 heisenberg kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0
 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 heisenberg kernel: Call Trace:
 heisenberg kernel:  commit_fs_roots+0x166/0x1d0 [btrfs]
 heisenberg kernel:  ? _cond_resched+0x15/0x30
 heisenberg kernel:  ? btrfs_run_delayed_refs+0xac/0x180 [btrfs]
 heisenberg kernel:  btrfs_commit_transaction+0x2bd/0x870 [btrfs]
 heisenberg kernel:  ? start_transaction+0x9d/0x3f0 [btrfs]
 heisenberg kernel:  transaction_kthread+0x147/0x180 [btrfs]
 heisenberg kernel:  ? btrfs_cleanup_transaction+0x530/0x530 [btrfs]
 heisenberg kernel:  kthread+0x112/0x130
 heisenberg kernel:  ? kthread_bind+0x30/0x30
 heisenberg kernel:  ret_from_fork+0x35/0x40
 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]---

Since fiemap (and btrfs_check_shared()) is a read-only operation, do not do
a transaction join to avoid the overhead of creating a new transaction (if
there is currently no running transaction) and introducing a potential
point of failure when the new transaction gets committed, instead use a
transaction attach to grab a handle for the currently running transaction
if any.
Reported-by: NChristoph Anton Mitterer <calestyo@scientia.net>
Link: https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/
Fixes: afce772e ("btrfs: fix check_shared for fiemap ioctl")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9f89d5de8631c7930898a601b6612e271aa2261c upstream.

When we set a subvolume to read-only mode we do not flush dellaloc for any
of its inodes (except if the filesystem is mounted with -o flushoncommit),
since it does not affect correctness for any subsequent operations - except
for a future send operation. The send operation will not be able to see the
delalloc data since the respective file extent items, inode item updates,
backreferences, etc, have not hit yet the subvolume and extent trees.

Effectively this means data loss, since the send stream will not contain
any data from existing delalloc. Another problem from this is that if the
writeback starts and finishes while the send operation is in progress, we
have the subvolume tree being being modified concurrently which can result
in send failing unexpectedly with EIO or hitting runtime errors, assertion
failures or hitting BUG_ONs, etc.

Simple reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ btrfs subvolume create /mnt/sv
  $ xfs_io -f -c "pwrite -S 0xea 0 108K" /mnt/sv/foo

  $ btrfs property set /mnt/sv ro true
  $ btrfs send -f /tmp/send.stream /mnt/sv

  $ od -t x1 -A d /mnt/sv/foo
  0000000 ea ea ea ea ea ea ea ea ea ea ea ea ea ea ea ea
  *
  0110592

  $ umount /mnt
  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt

  $ btrfs receive -f /tmp/send.stream /mnt
  $ echo $?
  0
  $ od -t x1 -A d /mnt/sv/foo
  0000000
  # ---> empty file

Since this a problem that affects send only, fix it in send by flushing
dellaloc for all the roots used by the send operation before send starts
to process the commit roots.

This is a problem that affects send since it was introduced (commit
31db9f7c ("Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive"))
but backporting it to older kernels has some dependencies:

- For kernels between 3.19 and 4.20, it depends on commit 3cd24c698004d2
  ("btrfs: use tagged writepage to mitigate livelock of snapshot") because
  the function btrfs_start_delalloc_snapshot() does not exist before that
  commit. So one has to either pick that commit or replace the calls to
  btrfs_start_delalloc_snapshot() in this patch with calls to
  btrfs_start_delalloc_inodes().

- For kernels older than 3.19 it also requires commit e5fa8f86
  ("Btrfs: ensure send always works on roots without orphans") because
  it depends on the function ensure_commit_roots_uptodate() which that
  commits introduced.

- No dependencies for 5.0+ kernels.

A test case for fstests follows soon.

CC: stable@vger.kernel.org # 3.19+
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c2d1b3aae33605a61cbab445d8ae1c708ccd2698 upstream.

Up until now trimming the freespace was done irrespective of what the
arguments of the FITRIM ioctl were. For example fstrim's -o/-l arguments
will be entirely ignored. Fix it by correctly handling those paramter.
This requires breaking if the found freespace extent is after the end of
the passed range as well as completing trim after trimming
fstrim_range::len bytes.

Fixes: 499f377f ("btrfs: iterate over unused chunk space in FITRIM")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 537f38f019fa0b762dbb4c0fc95d7fcce9db8e2d upstream.

If a an eb fails to be read for whatever reason - it's corrupted on disk
and parent transid/key validations fail or IO for eb pages fail then
this buffer must be removed from the buffer cache. Currently the code
calls free_extent_buffer if an error occurs. Unfortunately this doesn't
achieve the desired behavior since btrfs_find_create_tree_block returns
with eb->refs == 2.

On the other hand free_extent_buffer will only decrement the refs once
leaving it added to the buffer cache radix tree.  This enables later
code to look up the buffer from the cache and utilize it potentially
leading to a crash.

The correct way to free the buffer is call free_extent_buffer_stale.
This function will correctly call atomic_dec explicitly for the buffer
and subsequently call release_extent_buffer which will decrement the
final reference thus correctly remove the invalid buffer from buffer
cache. This change affects only newly allocated buffers since they have
eb->refs == 2.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=202755Reported-by: NJungyeon <jungyeon@gatech.edu>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 448de471cd4cab0cedd15770082567a69a784a11 upstream.

[BUG]
When reading a file from a fuzzed image, kernel can panic like:

  BTRFS warning (device loop0): csum failed root 5 ino 270 off 0 csum 0x98f94189 expected csum 0x00000000 mirror 1
  assertion failed: !memcmp_extent_buffer(b, &disk_key, offsetof(struct btrfs_leaf, items[0].key), sizeof(disk_key)), file: fs/btrfs/ctree.c, line: 2544
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.h:3500!
  invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
  RIP: 0010:btrfs_search_slot.cold.24+0x61/0x63 [btrfs]
  Call Trace:
   btrfs_lookup_csum+0x52/0x150 [btrfs]
   __btrfs_lookup_bio_sums+0x209/0x640 [btrfs]
   btrfs_submit_bio_hook+0x103/0x170 [btrfs]
   submit_one_bio+0x59/0x80 [btrfs]
   extent_read_full_page+0x58/0x80 [btrfs]
   generic_file_read_iter+0x2f6/0x9d0
   __vfs_read+0x14d/0x1a0
   vfs_read+0x8d/0x140
   ksys_read+0x52/0xc0
   do_syscall_64+0x60/0x210
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

[CAUSE]
The fuzzed image has a corrupted leaf whose first key doesn't match its
parent:

  checksum tree key (CSUM_TREE ROOT_ITEM 0)
  node 29741056 level 1 items 14 free 107 generation 19 owner CSUM_TREE
  fs uuid 3381d111-94a3-4ac7-8f39-611bbbdab7e6
  chunk uuid 9af1c3c7-2af5-488b-8553-530bd515f14c
  	...
          key (EXTENT_CSUM EXTENT_CSUM 79691776) block 29761536 gen 19

  leaf 29761536 items 1 free space 1726 generation 19 owner CSUM_TREE
  leaf 29761536 flags 0x1(WRITTEN) backref revision 1
  fs uuid 3381d111-94a3-4ac7-8f39-611bbbdab7e6
  chunk uuid 9af1c3c7-2af5-488b-8553-530bd515f14c
          item 0 key (EXTENT_CSUM EXTENT_CSUM 8798638964736) itemoff 1751 itemsize 2244
                  range start 8798638964736 end 8798641262592 length 2297856

When reading the above tree block, we have extent_buffer->refs = 2 in
the context:

- initial one from __alloc_extent_buffer()
  alloc_extent_buffer()
  |- __alloc_extent_buffer()
     |- atomic_set(&eb->refs, 1)

- one being added to fs_info->buffer_radix
  alloc_extent_buffer()
  |- check_buffer_tree_ref()
     |- atomic_inc(&eb->refs)

So if even we call free_extent_buffer() in read_tree_block or other
similar situation, we only decrease the refs by 1, it doesn't reach 0
and won't be freed right now.

The staled eb and its corrupted content will still be kept cached.

Furthermore, we have several extra cases where we either don't do first
key check or the check is not proper for all callers:

- scrub
  We just don't have first key in this context.

- shared tree block
  One tree block can be shared by several snapshot/subvolume trees.
  In that case, the first key check for one subvolume doesn't apply to
  another.

So for the above reasons, a corrupted extent buffer can sneak into the
buffer cache.

[FIX]
Call verify_level_key in read_block_for_search to do another
verification. For that purpose the function is exported.

Due to above reasons, although we can free corrupted extent buffer from
cache, we still need the check in read_block_for_search(), for scrub and
shared tree blocks.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=202755
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202757
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202759
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202761
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202767
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202769Reported-by: NYoon Jungyeon <jungyeon@gatech.edu>
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 50b29d8f033a7c88c5bc011abc2068b1691ab755 upstream.

Instead of removing EXT4_MOUNT_JOURNAL_CHECKSUM from s_def_mount_opt as
I assume was intended, all other options were blown away leading to
_ext4_show_options() output being incorrect.

Fixes: 1e381f60 ("ext4: do not allow journal_opts for fs w/o journal")
Signed-off-by: NDebabrata Banerjee <dbanerje@akamai.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 310a997fd74de778b9a4848a64be9cda9f18764a upstream.

It is never possible, that number of block groups decreases,
since only online grow is supported.

But after a growing occured, we have to zero inode tables
for just created new block groups.

Fixes: 19c5246d ("ext4: add new online resize interface")
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7bc04c5c2cc467c5b40f2b03ba08da174a0d5fa7 upstream.

When remounting with debug_want_extra_isize, we were not performing the
same checks that we do during a normal mount.  That allowed us to set a
value for s_want_extra_isize that reached outside the s_inode_size.

Fixes: e2b911c5 ("ext4: clean up feature test macros with predicate functions")
Reported-by: syzbot+f584efa0ac7213c226b7@syzkaller.appspotmail.com
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NBarret Rhoden <brho@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8c380ab4b7b59c0c602743810be1b712514eaebc upstream.

The reference to iloc.bh has been dropped in ext4_mark_iloc_dirty.
However, the reference is dropped again if error occurs during
ext4_handle_dirty_metadata, which may result in use-after-free bugs.

Fixes: fb265c9cb49e("ext4: add ext4_sb_bread() to disambiguate ENOMEM cases")
Signed-off-by: NPan Bian <bianpan2016@163.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e5d01196c0428a206f307e9ee5f6842964098ff0 upstream.

In other places in fs/ext4/xattr.c, if e_value_inum is non-zero, the
code ignores the value in e_value_offs.  The e_value_offs *should* be
zero, but we shouldn't depend upon it, since it might not be true in a
corrupted/fuzzed file system.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202897
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202877Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 31562b954b60f02acb91b7349dc6432d3f8c3c5f upstream.

The sanity check in mb_find_extent() only checked that returned extent
does not extend past blocksize * 8, however it should not extend past
EXT4_CLUSTERS_PER_GROUP(sb). This can happen when clusters_per_group <
blocksize * 8 and the tail of the bitmap is not properly filled by 1s
which happened e.g. when ancient kernels have grown the filesystem.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 742b06b5628f2cd23cb51a034cb54dc33c6162c5 upstream.

We hit a BUG at fs/buffer.c:3057 if we detached the nbd device
before unmounting ext4 filesystem.

The typical chain of events leading to the BUG:
jbd2_write_superblock
  submit_bh
    submit_bh_wbc
      BUG_ON(!buffer_mapped(bh));

The block device is removed and all the pages are invalidated. JBD2
was trying to write journal superblock to the block device which is
no longer present.

Fix this by checking the journal superblock's buffer head prior to
submitting.
Reported-by: NEric Ren <renzhen@linux.alibaba.com>
Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e091eab028f9253eac5c04f9141bbc9d170acab3 upstream.

In some cases, ocfs2_iget() reads the data of inode, which has been
deleted for some reason.  That will make the system panic.  So We should
judge whether this inode has been deleted, and tell the caller that the
inode is a bad inode.

For example, the ocfs2 is used as the backed of nfs, and the client is
nfsv3.  This issue can be reproduced by the following steps.

on the nfs server side,
..../patha/pathb

Step 1: The process A was scheduled before calling the function fh_verify.

Step 2: The process B is removing the 'pathb', and just completed the call
to function dput.  Then the dentry of 'pathb' has been deleted from the
dcache, and all ancestors have been deleted also.  The relationship of
dentry and inode was deleted through the function hlist_del_init.  The
following is the call stack.
dentry_iput->hlist_del_init(&dentry->d_u.d_alias)

At this time, the inode is still in the dcache.

Step 3: The process A call the function ocfs2_get_dentry, which get the
inode from dcache.  Then the refcount of inode is 1.  The following is the
call stack.
nfsd3_proc_getacl->fh_verify->exportfs_decode_fh->fh_to_dentry(ocfs2_get_dentry)

Step 4: Dirty pages are flushed by bdi threads.  So the inode of 'patha'
is evicted, and this directory was deleted.  But the inode of 'pathb'
can't be evicted, because the refcount of the inode was 1.

Step 5: The process A keep running, and call the function
reconnect_path(in exportfs_decode_fh), which call function
ocfs2_get_parent of ocfs2.  Get the block number of parent
directory(patha) by the name of ...  Then read the data from disk by the
block number.  But this inode has been deleted, so the system panic.

Process A                                             Process B
1. in nfsd3_proc_getacl                   |
2.                                        |        dput
3. fh_to_dentry(ocfs2_get_dentry)         |
4. bdi flush dirty cache                  |
5. ocfs2_iget                             |

[283465.542049] OCFS2: ERROR (device sdp): ocfs2_validate_inode_block:
Invalid dinode #580640: OCFS2_VALID_FL not set

[283465.545490] Kernel panic - not syncing: OCFS2: (device sdp): panic forced
after error

[283465.546889] CPU: 5 PID: 12416 Comm: nfsd Tainted: G        W
4.1.12-124.18.6.el6uek.bug28762940v3.x86_64 #2
[283465.548382] Hardware name: VMware, Inc. VMware Virtual Platform/440BX
Desktop Reference Platform, BIOS 6.00 09/21/2015
[283465.549657]  0000000000000000 ffff8800a56fb7b8 ffffffff816e839c
ffffffffa0514758
[283465.550392]  000000000008dc20 ffff8800a56fb838 ffffffff816e62d3
0000000000000008
[283465.551056]  ffff880000000010 ffff8800a56fb848 ffff8800a56fb7e8
ffff88005df9f000
[283465.551710] Call Trace:
[283465.552516]  [<ffffffff816e839c>] dump_stack+0x63/0x81
[283465.553291]  [<ffffffff816e62d3>] panic+0xcb/0x21b
[283465.554037]  [<ffffffffa04e66b0>] ocfs2_handle_error+0xf0/0xf0 [ocfs2]
[283465.554882]  [<ffffffffa04e7737>] __ocfs2_error+0x67/0x70 [ocfs2]
[283465.555768]  [<ffffffffa049c0f9>] ocfs2_validate_inode_block+0x229/0x230
[ocfs2]
[283465.556683]  [<ffffffffa047bcbc>] ocfs2_read_blocks+0x46c/0x7b0 [ocfs2]
[283465.557408]  [<ffffffffa049bed0>] ? ocfs2_inode_cache_io_unlock+0x20/0x20
[ocfs2]
[283465.557973]  [<ffffffffa049f0eb>] ocfs2_read_inode_block_full+0x3b/0x60
[ocfs2]
[283465.558525]  [<ffffffffa049f5ba>] ocfs2_iget+0x4aa/0x880 [ocfs2]
[283465.559082]  [<ffffffffa049146e>] ocfs2_get_parent+0x9e/0x220 [ocfs2]
[283465.559622]  [<ffffffff81297c05>] reconnect_path+0xb5/0x300
[283465.560156]  [<ffffffff81297f46>] exportfs_decode_fh+0xf6/0x2b0
[283465.560708]  [<ffffffffa062faf0>] ? nfsd_proc_getattr+0xa0/0xa0 [nfsd]
[283465.561262]  [<ffffffff810a8196>] ? prepare_creds+0x26/0x110
[283465.561932]  [<ffffffffa0630860>] fh_verify+0x350/0x660 [nfsd]
[283465.562862]  [<ffffffffa0637804>] ? nfsd_cache_lookup+0x44/0x630 [nfsd]
[283465.563697]  [<ffffffffa063a8b9>] nfsd3_proc_getattr+0x69/0xf0 [nfsd]
[283465.564510]  [<ffffffffa062cf60>] nfsd_dispatch+0xe0/0x290 [nfsd]
[283465.565358]  [<ffffffffa05eb892>] ? svc_tcp_adjust_wspace+0x12/0x30
[sunrpc]
[283465.566272]  [<ffffffffa05ea652>] svc_process_common+0x412/0x6a0 [sunrpc]
[283465.567155]  [<ffffffffa05eaa03>] svc_process+0x123/0x210 [sunrpc]
[283465.568020]  [<ffffffffa062c90f>] nfsd+0xff/0x170 [nfsd]
[283465.568962]  [<ffffffffa062c810>] ? nfsd_destroy+0x80/0x80 [nfsd]
[283465.570112]  [<ffffffff810a622b>] kthread+0xcb/0xf0
[283465.571099]  [<ffffffff810a6160>] ? kthread_create_on_node+0x180/0x180
[283465.572114]  [<ffffffff816f11b8>] ret_from_fork+0x58/0x90
[283465.573156]  [<ffffffff810a6160>] ? kthread_create_on_node+0x180/0x180

Link: http://lkml.kernel.org/r/1554185919-3010-1-git-send-email-sunny.s.zhang@oracle.comSigned-off-by: NShuning Zhang <sunny.s.zhang@oracle.com>
Reviewed-by: NJoseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: piaojun <piaojun@huawei.com>
Cc: "Gang He" <ghe@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1b426bac66e6cc83c9f2d92b96e4e72acf43419a upstream.

hugetlb uses a fault mutex hash table to prevent page faults of the
same pages concurrently.  The key for shared and private mappings is
different.  Shared keys off address_space and file index.  Private keys
off mm and virtual address.  Consider a private mappings of a populated
hugetlbfs file.  A fault will map the page from the file and if needed
do a COW to map a writable page.

Hugetlbfs hole punch uses the fault mutex to prevent mappings of file
pages.  It uses the address_space file index key.  However, private
mappings will use a different key and could race with this code to map
the file page.  This causes problems (BUG) for the page cache remove
code as it expects the page to be unmapped.  A sample stack is:

page dumped because: VM_BUG_ON_PAGE(page_mapped(page))
kernel BUG at mm/filemap.c:169!
...
RIP: 0010:unaccount_page_cache_page+0x1b8/0x200
...
Call Trace:
__delete_from_page_cache+0x39/0x220
delete_from_page_cache+0x45/0x70
remove_inode_hugepages+0x13c/0x380
? __add_to_page_cache_locked+0x162/0x380
hugetlbfs_fallocate+0x403/0x540
? _cond_resched+0x15/0x30
? __inode_security_revalidate+0x5d/0x70
? selinux_file_permission+0x100/0x130
vfs_fallocate+0x13f/0x270
ksys_fallocate+0x3c/0x80
__x64_sys_fallocate+0x1a/0x20
do_syscall_64+0x5b/0x180
entry_SYSCALL_64_after_hwframe+0x44/0xa9

There seems to be another potential COW issue/race with this approach
of different private and shared keys as noted in commit 8382d914
("mm, hugetlb: improve page-fault scalability").

Since every hugetlb mapping (even anon and private) is actually a file
mapping, just use the address_space index key for all mappings.  This
results in potentially more hash collisions.  However, this should not
be the common case.

Link: http://lkml.kernel.org/r/20190328234704.27083-3-mike.kravetz@oracle.com
Link: http://lkml.kernel.org/r/20190412165235.t4sscoujczfhuiyt@linux-r8p5
Fixes: b5cec28d ("hugetlbfs: truncate_hugepages() takes a range of pages")
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: NDavidlohr Bueso <dbueso@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit fce86ff5802bac3a7b19db171aa1949ef9caac31 upstream.

Starting with c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page
protection by insert_pfn_pmd()") vmf_insert_pfn_pmd() internally calls
pmdp_set_access_flags().  That helper enforces a pmd aligned @address
argument via VM_BUG_ON() assertion.

Update the implementation to take a 'struct vm_fault' argument directly
and apply the address alignment fixup internally to fix crash signatures
like:

    kernel BUG at arch/x86/mm/pgtable.c:515!
    invalid opcode: 0000 [#1] SMP NOPTI
    CPU: 51 PID: 43713 Comm: java Tainted: G           OE     4.19.35 #1
    [..]
    RIP: 0010:pmdp_set_access_flags+0x48/0x50
    [..]
    Call Trace:
     vmf_insert_pfn_pmd+0x198/0x350
     dax_iomap_fault+0xe82/0x1190
     ext4_dax_huge_fault+0x103/0x1f0
     ? __switch_to_asm+0x40/0x70
     __handle_mm_fault+0x3f6/0x1370
     ? __switch_to_asm+0x34/0x70
     ? __switch_to_asm+0x40/0x70
     handle_mm_fault+0xda/0x200
     __do_page_fault+0x249/0x4f0
     do_page_fault+0x32/0x110
     ? page_fault+0x8/0x30
     page_fault+0x1e/0x30

Link: http://lkml.kernel.org/r/155741946350.372037.11148198430068238140.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()")
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Reported-by: NPiotr Balcer <piotr.balcer@intel.com>
Tested-by: NYan Ma <yan.ma@intel.com>
Tested-by: NPankaj Gupta <pagupta@redhat.com>
Reviewed-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Chandan Rajendra <chandan@linux.ibm.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 21bd68f196ca91fc0f3d9bd1b32f6e530e8c1c88 ]

__pagevec_release() complains loudly if any page in the vector is still
locked.  The pages need to be locked for generic_error_remove_page(), but
that function doesn't actually unlock them.

Unlock the pages afterwards.
Signed-off-by: NMarc Dionne <marc.dionne@auristor.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NJonathan Billings <jsbillin@umich.edu>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 998267900cee901c5d1dfa029a6304d00acbc29f upstream.

smp_mb__before_atomic() can not be applied to atomic_set().  Remove the
barrier and rely on RELEASE synchronization.

Fixes: ba16b284 ("kernfs: add an API to get kernfs node from inode number")
Cc: stable@vger.kernel.org
Signed-off-by: NAndrea Parri <andrea.parri@amarulasolutions.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock

[ Upstream commit 10dce8af34226d90fa56746a934f8da5dcdba3df ]

Commit 9c225f26 ("vfs: atomic f_pos accesses as per POSIX") added
locking for file.f_pos access and in particular made concurrent read and
write not possible - now both those functions take f_pos lock for the
whole run, and so if e.g. a read is blocked waiting for data, write will
deadlock waiting for that read to complete.

This caused regression for stream-like files where previously read and
write could run simultaneously, but after that patch could not do so
anymore. See e.g. commit 581d21a2 ("xenbus: fix deadlock on writes
to /proc/xen/xenbus") which fixes such regression for particular case of
/proc/xen/xenbus.

The patch that added f_pos lock in 2014 did so to guarantee POSIX thread
safety for read/write/lseek and added the locking to file descriptors of
all regular files. In 2014 that thread-safety problem was not new as it
was already discussed earlier in 2006.

However even though 2006'th version of Linus's patch was adding f_pos
locking "only for files that are marked seekable with FMODE_LSEEK (thus
avoiding the stream-like objects like pipes and sockets)", the 2014
version - the one that actually made it into the tree as 9c225f26 -
is doing so irregardless of whether a file is seekable or not.

See

    https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/
    https://lwn.net/Articles/180387
    https://lwn.net/Articles/180396

for historic context.

The reason that it did so is, probably, that there are many files that
are marked non-seekable, but e.g. their read implementation actually
depends on knowing current position to correctly handle the read. Some
examples:

	kernel/power/user.c		snapshot_read
	fs/debugfs/file.c		u32_array_read
	fs/fuse/control.c		fuse_conn_waiting_read + ...
	drivers/hwmon/asus_atk0110.c	atk_debugfs_ggrp_read
	arch/s390/hypfs/inode.c		hypfs_read_iter
	...

Despite that, many nonseekable_open users implement read and write with
pure stream semantics - they don't depend on passed ppos at all. And for
those cases where read could wait for something inside, it creates a
situation similar to xenbus - the write could be never made to go until
read is done, and read is waiting for some, potentially external, event,
for potentially unbounded time -> deadlock.

Besides xenbus, there are 14 such places in the kernel that I've found
with semantic patch (see below):

	drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write()
	drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write()
	drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write()
	drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write()
	net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write()
	drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write()
	drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write()
	drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write()
	net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write()
	drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write()
	drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write()
	drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write()
	drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write()
	drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write()

In addition to the cases above another regression caused by f_pos
locking is that now FUSE filesystems that implement open with
FOPEN_NONSEEKABLE flag, can no longer implement bidirectional
stream-like files - for the same reason as above e.g. read can deadlock
write locking on file.f_pos in the kernel.

FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990 ("fuse:
implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp
in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and
write routines not depending on current position at all, and with both
read and write being potentially blocking operations:

See

    https://github.com/libfuse/osspd
    https://lwn.net/Articles/308445

    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406
    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477
    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510

Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as
"somewhat pipe-like files ..." with read handler not using offset.
However that test implements only read without write and cannot exercise
the deadlock scenario:

    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131
    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163
    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216

I've actually hit the read vs write deadlock for real while implementing
my FUSE filesystem where there is /head/watch file, for which open
creates separate bidirectional socket-like stream in between filesystem
and its user with both read and write being later performed
simultaneously. And there it is semantically not easy to split the
stream into two separate read-only and write-only channels:

    https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169

Let's fix this regression. The plan is:

1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS -
   doing so would break many in-kernel nonseekable_open users which
   actually use ppos in read/write handlers.

2. Add stream_open() to kernel to open stream-like non-seekable file
   descriptors. Read and write on such file descriptors would never use
   nor change ppos. And with that property on stream-like files read and
   write will be running without taking f_pos lock - i.e. read and write
   could be running simultaneously.

3. With semantic patch search and convert to stream_open all in-kernel
   nonseekable_open users for which read and write actually do not
   depend on ppos and where there is no other methods in file_operations
   which assume @offset access.

4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via
   steam_open if that bit is present in filesystem open reply.

   It was tempting to change fs/fuse/ open handler to use stream_open
   instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but
   grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
   and in particular GVFS which actually uses offset in its read and
   write handlers

	https://codesearch.debian.net/search?q=-%3Enonseekable+%3D
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481

   so if we would do such a change it will break a real user.

5. Add stream_open and FOPEN_STREAM handling to stable kernels starting
   from v3.14+ (the kernel where 9c225f26 first appeared).

   This will allow to patch OSSPD and other FUSE filesystems that
   provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE
   in their open handler and this way avoid the deadlock on all kernel
   versions. This should work because fs/fuse/ ignores unknown open
   flags returned from a filesystem and so passing FOPEN_STREAM to a
   kernel that is not aware of this flag cannot hurt. In turn the kernel
   that is not aware of FOPEN_STREAM will be < v3.14 where just
   FOPEN_NONSEEKABLE is sufficient to implement streams without read vs
   write deadlock.

This patch adds stream_open, converts /proc/xen/xenbus to it and adds
semantic patch to automatically locate in-kernel places that are either
required to be converted due to read vs write deadlock, or that are just
safe to be converted because read and write do not use ppos and there
are no other funky methods in file_operations.

Regarding semantic patch I've verified each generated change manually -
that it is correct to convert - and each other nonseekable_open instance
left - that it is either not correct to convert there, or that it is not
converted due to current stream_open.cocci limitations.

The script also does not convert files that should be valid to convert,
but that currently have .llseek = noop_llseek or generic_file_llseek for
unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: NKirill Smelkov <kirr@nexedi.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 58b6e5e8f1addd44583d61b0a03c0f5519527e35 ]

When mknod is used to create a block special file in hugetlbfs, it will
allocate an inode and kmalloc a 'struct resv_map' via resv_map_alloc().
inode->i_mapping->private_data will point the newly allocated resv_map.
However, when the device special file is opened bd_acquire() will set
inode->i_mapping to bd_inode->i_mapping.  Thus the pointer to the
allocated resv_map is lost and the structure is leaked.

Programs to reproduce:
        mount -t hugetlbfs nodev hugetlbfs
        mknod hugetlbfs/dev b 0 0
        exec 30<> hugetlbfs/dev
        umount hugetlbfs/

resv_map structures are only needed for inodes which can have associated
page allocations.  To fix the leak, only allocate resv_map for those
inodes which could possibly be associated with page allocations.

Link: http://lkml.kernel.org/r/20190401213101.16476-1-mike.kravetz@oracle.comSigned-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Reported-by: NYufen Yu <yuyufen@huawei.com>
Suggested-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 93b919da64c15b90953f96a536e5e61df896ca57 ]

symlink body shouldn't be freed without an RCU delay.  Switch debugfs to
->destroy_inode() and use of call_rcu(); free both the inode and symlink
body in the callback.  Similar to solution for bpf, only here it's even
more obvious that ->evict_inode() can be dropped.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 4fdcfab5b5537c21891e22e65996d4d0dd8ab4ca ]

free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit daf5cc27eed99afdea8d96e71b89ba41f5406ef6 ]

free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NSasha Levin (Microsoft) <sashal@kernel.org>

[ Upstream commit 5a698243930c441afccec04e4d5dc8febfd2b775 ]

Specifying a retrans=0 mount parameter to a NFS/TCP mount, is
inadvertently causing the NFS client to rewrite any specified
timeout parameter to the default of 60 seconds.

Fixes: a956beda ("NFS: Allow the mount option retrans=0")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin (Microsoft) <sashal@kernel.org>

commit 15fab63e1e57be9fdb5eec1bbc5916e9825e9acb upstream.

Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount.  All
callers converted to handle a failure.
Reported-by: NJann Horn <jannh@google.com>
Signed-off-by: NMatthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit af5c72b1fc7a00aa484e90b0c4e0eeb582545634 upstream.

aio_poll() has to cope with several unpleasant problems:
	* requests that might stay around indefinitely need to
be made visible for io_cancel(2); that must not be done to
a request already completed, though.
	* in cases when ->poll() has placed us on a waitqueue,
wakeup might have happened (and request completed) before ->poll()
returns.
	* worse, in some early wakeup cases request might end
up re-added into the queue later - we can't treat "woken up and
currently not in the queue" as "it's not going to stick around
indefinitely"
	* ... moreover, ->poll() might have decided not to
put it on any queues to start with, and that needs to be distinguished
from the previous case
	* ->poll() might have tried to put us on more than one queue.
Only the first will succeed for aio poll, so we might end up missing
wakeups.  OTOH, we might very well notice that only after the
wakeup hits and request gets completed (all before ->poll() gets
around to the second poll_wait()).  In that case it's too late to
decide that we have an error.

req->woken was an attempt to deal with that.  Unfortunately, it was
broken.  What we need to keep track of is not that wakeup has happened -
the thing might come back after that.  It's that async reference is
already gone and won't come back, so we can't (and needn't) put the
request on the list of cancellables.

The easiest case is "request hadn't been put on any waitqueues"; we
can tell by seeing NULL apt.head, and in that case there won't be
anything async.  We should either complete the request ourselves
(if vfs_poll() reports anything of interest) or return an error.

In all other cases we get exclusion with wakeups by grabbing the
queue lock.

If request is currently on queue and we have something interesting
from vfs_poll(), we can steal it and complete the request ourselves.

If it's on queue and vfs_poll() has not reported anything interesting,
we either put it on the cancellable list, or, if we know that it
hadn't been put on all queues ->poll() wanted it on, we steal it and
return an error.

If it's _not_ on queue, it's either been already dealt with (in which
case we do nothing), or there's aio_poll_complete_work() about to be
executed.  In that case we either put it on the cancellable list,
or, if we know it hadn't been put on all queues ->poll() wanted it on,
simulate what cancel would've done.

It's a lot more convoluted than I'd like it to be.  Single-consumer APIs
suck, and unfortunately aio is not an exception...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 2bb874c0d873d13bd9b9b9c6d7b7c4edab18c8b4 upstream.

Instead of having aio_complete() set ->ki_res.{res,res2}, do that
explicitly in its callers, drop the reference (as aio_complete()
used to do) and delay the rest until the final iocb_put().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a9339b7855094ba11a97e8822ae038135e879e79 upstream.

We want to separate forming the resulting io_event from putting it
into the ring buffer.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 833f4154ed560232120bc475935ee1d6a20e159f upstream.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b53119f13a04879c3bf502828d99d13726639ead upstream.

aio_poll() is not the only case that needs file pinned; worse, while
aio_read()/aio_write() can live without pinning iocb itself, the
proof is rather brittle and can easily break on later changes.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 84c4e1f89fefe70554da0ab33be72c9be7994379 upstream.

Al Viro root-caused a race where the IOCB_CMD_POLL handling of
fget/fput() could cause us to access the file pointer after it had
already been freed:

 "In more details - normally IOCB_CMD_POLL handling looks so:

   1) io_submit(2) allocates aio_kiocb instance and passes it to
      aio_poll()

   2) aio_poll() resolves the descriptor to struct file by req->file =
      fget(iocb->aio_fildes)

   3) aio_poll() sets ->woken to false and raises ->ki_refcnt of that
      aio_kiocb to 2 (bumps by 1, that is).

   4) aio_poll() calls vfs_poll(). After sanity checks (basically,
      "poll_wait() had been called and only once") it locks the queue.
      That's what the extra reference to iocb had been for - we know we
      can safely access it.

   5) With queue locked, we check if ->woken has already been set to
      true (by aio_poll_wake()) and, if it had been, we unlock the
      queue, drop a reference to aio_kiocb and bugger off - at that
      point it's a responsibility to aio_poll_wake() and the stuff
      called/scheduled by it. That code will drop the reference to file
      in req->file, along with the other reference to our aio_kiocb.

   6) otherwise, we see whether we need to wait. If we do, we unlock the
      queue, drop one reference to aio_kiocb and go away - eventual
      wakeup (or cancel) will deal with the reference to file and with
      the other reference to aio_kiocb

   7) otherwise we remove ourselves from waitqueue (still under the
      queue lock), so that wakeup won't get us. No async activity will
      be happening, so we can safely drop req->file and iocb ourselves.

  If wakeup happens while we are in vfs_poll(), we are fine - aio_kiocb
  won't get freed under us, so we can do all the checks and locking
  safely. And we don't touch ->file if we detect that case.

  However, vfs_poll() most certainly *does* touch the file it had been
  given. So wakeup coming while we are still in ->poll() might end up
  doing fput() on that file. That case is not too rare, and usually we
  are saved by the still present reference from descriptor table - that
  fput() is not the final one.

  But if another thread closes that descriptor right after our fget()
  and wakeup does happen before ->poll() returns, we are in trouble -
  final fput() done while we are in the middle of a method:

Al also wrote a patch to take an extra reference to the file descriptor
to fix this, but I instead suggested we just streamline the whole file
pointer handling by submit_io() so that the generic aio submission code
simply keeps the file pointer around until the aio has completed.

Fixes: bfe4037e ("aio: implement IOCB_CMD_POLL")
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Reported-by: syzbot+503d4cc169fcec1cb18c@syzkaller.appspotmail.com
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ec51f8ee1e63498e9f521ec0e5a6d04622bb2c67 upstream.

A recent optimization had left private uninitialized.

Fixes: 2bc4ca9bb600 ("aio: don't zero entire aio_kiocb aio_get_req()")
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 875736bb3f3ded168469f6a14df7a938416a99d5 upstream.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>