linux-stable.git/drivers, branch v4.17.4

virt: vbox: Only copy_from_user the request-header once

2018-07-03T09:27:12+00:00

commit bd23a7269834dc7c1f93e83535d16ebc44b75eba upstream.

In vbg_misc_device_ioctl(), the header of the ioctl argument is copied from
the userspace pointer 'arg' and saved to the kernel object 'hdr'. Then the
'version', 'size_in', and 'size_out' fields of 'hdr' are verified.

Before this commit, after the checks a buffer for the entire request would
be allocated and then all data including the verified header would be
copied from the userspace 'arg' pointer again.

Given that the 'arg' pointer resides in userspace, a malicious userspace
process can race to change the data pointed to by 'arg' between the two
copies. By doing so, the user can bypass the verifications on the ioctl
argument.

This commit fixes this by using the already checked copy of the header
to fill the header part of the allocated buffer and only copying the
remainder of the data from userspace.

Signed-off-by: Wenwen Wang 
Reviewed-by: Hans de Goede 
Cc: Justin Forbes 
Signed-off-by: Greg Kroah-Hartman

dm thin: handle running out of data space vs concurrent discard

2018-07-03T09:27:12+00:00

commit a685557fbbc3122ed11e8ad3fa63a11ebc5de8c3 upstream.

Discards issued to a DM thin device can complete to userspace (via
fstrim) _before_ the metadata changes associated with the discards is
reflected in the thinp superblock (e.g. free blocks).  As such, if a
user constructs a test that loops repeatedly over these steps, block
allocation can fail due to discards not having completed yet:
1) fill thin device via filesystem file
2) remove file
3) fstrim

From initial report, here:
https://www.redhat.com/archives/dm-devel/2018-April/msg00022.html

"The root cause of this issue is that dm-thin will first remove
mapping and increase corresponding blocks' reference count to prevent
them from being reused before DISCARD bios get processed by the
underlying layers. However. increasing blocks' reference count could
also increase the nr_allocated_this_transaction in struct sm_disk
which makes smd->old_ll.nr_allocated +
smd->nr_allocated_this_transaction bigger than smd->old_ll.nr_blocks.
In this case, alloc_data_block() will never commit metadata to reset
the begin pointer of struct sm_disk, because sm_disk_get_nr_free()
always return an underflow value."

While there is room for improvement to the space-map accounting that
thinp is making use of: the reality is this test is inherently racey and
will result in the previous iteration's fstrim's discard(s) completing
vs concurrent block allocation, via dd, in the next iteration of the
loop.

No amount of space map accounting improvements will be able to allow
user's to use a block before a discard of that block has completed.

So the best we can really do is allow DM thinp to gracefully handle such
aggressive use of all the pool's data by degrading the pool into
out-of-data-space (OODS) mode.  We _should_ get that behaviour already
(if space map accounting didn't falsely cause alloc_data_block() to
believe free space was available).. but short of that we handle the
current reality that dm_pool_alloc_data_block() can return -ENOSPC.

Reported-by: Dennis Yang 
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm zoned: avoid triggering reclaim from inside dmz_map()

2018-07-03T09:27:12+00:00

commit 2d0b2d64d325e22939d9db3ba784f1236459ed98 upstream.

This patch avoids that lockdep reports the following:

======================================================
WARNING: possible circular locking dependency detected
4.18.0-rc1 #62 Not tainted
------------------------------------------------------
kswapd0/84 is trying to acquire lock:
00000000c313516d (&xfs_nondir_ilock_class){++++}, at: xfs_free_eofblocks+0xa2/0x1e0

but task is already holding lock:
00000000591c83ae (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (fs_reclaim){+.+.}:
  kmem_cache_alloc+0x2c/0x2b0
  radix_tree_node_alloc.constprop.19+0x3d/0xc0
  __radix_tree_create+0x161/0x1c0
  __radix_tree_insert+0x45/0x210
  dmz_map+0x245/0x2d0 [dm_zoned]
  __map_bio+0x40/0x260
  __split_and_process_non_flush+0x116/0x220
  __split_and_process_bio+0x81/0x180
  __dm_make_request.isra.32+0x5a/0x100
  generic_make_request+0x36e/0x690
  submit_bio+0x6c/0x140
  mpage_readpages+0x19e/0x1f0
  read_pages+0x6d/0x1b0
  __do_page_cache_readahead+0x21b/0x2d0
  force_page_cache_readahead+0xc4/0x100
  generic_file_read_iter+0x7c6/0xd20
  __vfs_read+0x102/0x180
  vfs_read+0x9b/0x140
  ksys_read+0x55/0xc0
  do_syscall_64+0x5a/0x1f0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #1 (&dmz->chunk_lock){+.+.}:
  dmz_map+0x133/0x2d0 [dm_zoned]
  __map_bio+0x40/0x260
  __split_and_process_non_flush+0x116/0x220
  __split_and_process_bio+0x81/0x180
  __dm_make_request.isra.32+0x5a/0x100
  generic_make_request+0x36e/0x690
  submit_bio+0x6c/0x140
  _xfs_buf_ioapply+0x31c/0x590
  xfs_buf_submit_wait+0x73/0x520
  xfs_buf_read_map+0x134/0x2f0
  xfs_trans_read_buf_map+0xc3/0x580
  xfs_read_agf+0xa5/0x1e0
  xfs_alloc_read_agf+0x59/0x2b0
  xfs_alloc_pagf_init+0x27/0x60
  xfs_bmap_longest_free_extent+0x43/0xb0
  xfs_bmap_btalloc_nullfb+0x7f/0xf0
  xfs_bmap_btalloc+0x428/0x7c0
  xfs_bmapi_write+0x598/0xcc0
  xfs_iomap_write_allocate+0x15a/0x330
  xfs_map_blocks+0x1cf/0x3f0
  xfs_do_writepage+0x15f/0x7b0
  write_cache_pages+0x1ca/0x540
  xfs_vm_writepages+0x65/0xa0
  do_writepages+0x48/0xf0
  __writeback_single_inode+0x58/0x730
  writeback_sb_inodes+0x249/0x5c0
  wb_writeback+0x11e/0x550
  wb_workfn+0xa3/0x670
  process_one_work+0x228/0x670
  worker_thread+0x3c/0x390
  kthread+0x11c/0x140
  ret_from_fork+0x3a/0x50

-> #0 (&xfs_nondir_ilock_class){++++}:
  down_read_nested+0x43/0x70
  xfs_free_eofblocks+0xa2/0x1e0
  xfs_fs_destroy_inode+0xac/0x270
  dispose_list+0x51/0x80
  prune_icache_sb+0x52/0x70
  super_cache_scan+0x127/0x1a0
  shrink_slab.part.47+0x1bd/0x590
  shrink_node+0x3b5/0x470
  balance_pgdat+0x158/0x3b0
  kswapd+0x1ba/0x600
  kthread+0x11c/0x140
  ret_from_fork+0x3a/0x50

other info that might help us debug this:

Chain exists of:
  &xfs_nondir_ilock_class --> &dmz->chunk_lock --> fs_reclaim

Possible unsafe locking scenario:

     CPU0                    CPU1
     ----                    ----
lock(fs_reclaim);
                             lock(&dmz->chunk_lock);
                             lock(fs_reclaim);
lock(&xfs_nondir_ilock_class);

pmem: only set QUEUE_FLAG_DAX for fsdax mode

2018-07-03T09:27:11+00:00

commit 4557641b4c7046625c026fb809c47ef0d43ae595 upstream.

QUEUE_FLAG_DAX is an indication that a given block device supports
filesystem DAX and should not be set for PMEM namespaces which are in "raw"
mode.  These namespaces lack struct page and are prevented from
participating in filesystem DAX as of commit 569d0365f571 ("dax: require
'struct page' by default for filesystem dax").

Signed-off-by: Ross Zwisler 
Suggested-by: Mike Snitzer 
Fixes: 569d0365f571 ("dax: require 'struct page' by default for filesystem dax")
Cc: stable@vger.kernel.org
Acked-by: Dan Williams 
Reviewed-by: Toshi Kani 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm: use bio_split() when splitting out the already processed bio

2018-07-03T09:27:11+00:00

commit f21c601a2bb319ec19eb4562eadc7797d90fd90e upstream.

Use of bio_clone_bioset() is inefficient if there is no need to clone
the original bio's bio_vec array.  Best to use the bio_clone_fast()
variant.  Also, just using bio_advance() is only part of what is needed
to properly setup the clone -- it doesn't account for the various
bio_integrity() related work that also needs to be performed (see
bio_split).

Address both of these issues by switching from bio_clone_bioset() to
bio_split().

Fixes: 18a25da8 ("dm: ensure bio submission follows a depth-first tree walk")
Cc: stable@vger.kernel.org # 4.15+, requires removal of '&' before md->queue->bio_split
Reported-by: Christoph Hellwig 
Reviewed-by: NeilBrown 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

i2c: gpio: initialize SCL to HIGH again

2018-07-03T09:27:11+00:00

commit 12b731dd46d9ee646318e6e9dc587314a3908a46 upstream.

It seems that during the conversion from gpio* to gpiod*, the initial
state of SCL was wrongly switched to LOW. Fix it to be HIGH again.

Fixes: 7bb75029ef34 ("i2c: gpio: Enforce open drain through gpiolib")
Signed-off-by: Wolfram Sang 
Tested-by: Geert Uytterhoeven 
Reviewed-by: Linus Walleij 
Signed-off-by: Wolfram Sang 
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman

Revert "i2c: algo-bit: init the bus to a known state"

2018-07-03T09:27:11+00:00

commit 2a2c8ee2d72c4f1ba0f7fbb02dc74f971df0f934 upstream.

This reverts commit 3e5f06bed72fe72166a6778f630241a893f67799. As per
bugzilla #200045, this caused a regression. I don't really see a way to
fix it without having the hardware. So, revert the patch and I will fix
the issue I was seeing originally in the i2c-gpio driver itself. I
couldn't find new users of this algorithm since, so there should be no
one depending on the new behaviour.

Reported-by: Sergey Larin 
Fixes: 3e5f06bed72f ("i2c: algo-bit: init the bus to a known state")
Signed-off-by: Wolfram Sang 
Acked-by: Alex Deucher 
Tested-by: Sergey Larin 
Signed-off-by: Wolfram Sang 
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman

Input: elantech - fix V4 report decoding for module with middle key

2018-07-03T09:27:10+00:00

commit e0ae2519ca004a628fa55aeef969c37edce522d3 upstream.

Some touchpad has middle key and it will be indicated in bit 2 of packet[0].
We need to fix V4 formation's byte mask to prevent error decoding.

Signed-off-by: KT Liao 
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Greg Kroah-Hartman

Input: elantech - enable middle button of touchpads on ThinkPad P52

2018-07-03T09:27:10+00:00

commit 24bb555e6e46d96e2a954aa0295029a81cc9bbaa upstream.

PNPID is better way to identify the type of touchpads.
Enable middle button support on 2 types of touchpads on Lenovo P52.

Cc: stable@vger.kernel.org
Signed-off-by: Aaron Ma 
Reviewed-by: Benjamin Tissoires 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Greg Kroah-Hartman

Input: elan_i2c_smbus - fix more potential stack buffer overflows

2018-07-03T09:27:10+00:00

commit 50fc7b61959af4b95fafce7fe5dd565199e0b61a upstream.

Commit 40f7090bb1b4 ("Input: elan_i2c_smbus - fix corrupted stack")
fixed most of the functions using i2c_smbus_read_block_data() to
allocate a buffer with the maximum block size.  However three
functions were left unchanged:

* In elan_smbus_initialize(), increase the buffer size in the same
  way.
* In elan_smbus_calibrate_result(), the buffer is provided by the
  caller (calibrate_store()), so introduce a bounce buffer.  Also
  name the result buffer size.
* In elan_smbus_get_report(), the buffer is provided by the caller
  but happens to be the right length.  Add a compile-time assertion
  to ensure this remains the case.

Cc:  # 3.19+
Signed-off-by: Ben Hutchings 
Reviewed-by: Benjamin Tissoires 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Greg Kroah-Hartman