linux-stable.git/drivers/md/dm-thin.c, branch linux-6.2.y

dm: change "unsigned" to "unsigned int"

2023-04-13T15:02:34+00:00

[ Upstream commit 86a3238c7b9b759cb864f4f768ab2e24687dc0e6 ]

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer 
Stable-dep-of: f7b58a69fad9 ("dm: fix improper splitting for abnormal bios")
Signed-off-by: Sasha Levin

dm thin: fix deadlock when swapping to thin device

2023-03-30T10:51:35+00:00

commit 9bbf5feecc7eab2c370496c1c161bbfe62084028 upstream.

This is an already known issue that dm-thin volume cannot be used as
swap, otherwise a deadlock may happen when dm-thin internal memory
demand triggers swap I/O on the dm-thin volume itself.

But thanks to commit a666e5c05e7c ("dm: fix deadlock when swapping to
encrypted device"), the limit_swap_bios target flag can also be used
for dm-thin to avoid the recursive I/O when it is used as swap.

Fix is to simply set ti->limit_swap_bios to true in both pool_ctr()
and thin_ctr().

In my test, I create a dm-thin volume /dev/vg/swap and use it as swap
device. Then I run fio on another dm-thin volume /dev/vg/main and use
large --blocksize to trigger swap I/O onto /dev/vg/swap.

The following fio command line is used in my test,
  fio --name recursive-swap-io --lockmem 1 --iodepth 128 \
     --ioengine libaio --filename /dev/vg/main --rw randrw \
    --blocksize 1M --numjobs 32 --time_based --runtime=12h

Without this fix, the whole system can be locked up within 15 seconds.

With this fix, there is no any deadlock or hung task observed after
2 hours of running fio.

Furthermore, if blocksize is changed from 1M to 128M, after around 30
seconds fio has no visible I/O, and the out-of-memory killer message
shows up in kernel message. After around 20 minutes all fio processes
are killed and the whole system is back to being alive.

This is exactly what is expected when recursive I/O happens on dm-thin
volume when it is used as swap.

Depends-on: a666e5c05e7c ("dm: fix deadlock when swapping to encrypted device")
Cc: stable@vger.kernel.org
Signed-off-by: Coly Li 
Acked-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm thin: add cond_resched() to various workqueue loops

2023-03-10T08:29:21+00:00

[ Upstream commit e4f80303c2353952e6e980b23914e4214487f2a6 ]

Otherwise on resource constrained systems these workqueues may be too
greedy.

Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

Merge tag 'for-6.2/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2022-12-13T18:58:09+00:00

Pull device mapper updates from Mike Snitzer:

 - Fix use-after-free races due to missing resource cleanup during DM
   target destruction in DM targets: thin-pool, cache, integrity and
   clone.

 - Fix ABBA deadlocks in DM thin-pool and cache targets due to their use
   of a bufio client (that has a shrinker whose locking can cause the
   incorrect locking order).

 - Fix DM cache target to set its needs_check flag after first aborting
   the metadata (whereby using reset persistent-data objects to update
   the superblock with, otherwise the superblock update could be dropped
   due to aborting metadata). This was found with code-inspection when
   comparing with the equivalent in DM thinp code.

 - Fix DM thin-pool's presume to continue resuming the device even if
   the pool in is fail mode -- otherwise bios may never be failed up the
   IO stack (which will prevent resetting the thin-pool target via table
   reload)

 - Fix DM thin-pool's metadata to use proper btree root (from previous
   transaction) if metadata commit failed.

 - Add 'waitfor' module param to DM module (dm_mod) to allow dm-init to
   wait for the specified device before continuing with its DM target
   initialization.

* tag 'for-6.2/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: Use last transaction's pmd->root when commit failed
  dm init: add dm-mod.waitfor to wait for asynchronously probed block devices
  dm ioctl: fix a couple ioctl codes
  dm ioctl: a small code cleanup in list_version_get_info
  dm thin: resume even if in FAIL mode
  dm cache: set needs_check flag after aborting metadata
  dm cache: Fix ABBA deadlock between shrink_slab and dm_cache_metadata_abort
  dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata
  dm integrity: Fix UAF in dm_integrity_dtr()
  dm cache: Fix UAF in destroy()
  dm clone: Fix UAF in clone_dtr()
  dm thin: Fix UAF in run_timer_softirq()

block: remove bio_set_op_attrs

2022-12-07T16:43:12+00:00

This macro is obsolete, so replace the last few uses with open coded
bi_opf assignments.

Signed-off-by: Christoph Hellwig 
Acked-by: Coly Li >
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20221206144057.720846-1-hch@lst.de
Signed-off-by: Jens Axboe

dm thin: resume even if in FAIL mode

2022-12-01T16:43:41+00:00

If a thinpool set fail_io while suspending, resume will fail with:
 device-mapper: resume ioctl on vg-thinpool  failed: Invalid argument

The thin-pool also can't be removed if an in-flight bio is in the
deferred list.

This can be easily reproduced using:

  echo "offline" > /sys/block/sda/device/state
  dd if=/dev/zero of=/dev/mapper/thin bs=4K count=1
  dmsetup suspend /dev/mapper/pool
  mkfs.ext4 /dev/mapper/thin
  dmsetup resume /dev/mapper/pool

The root cause is maybe_resize_data_dev() will check fail_io and return
error before called dm_resume.

Fix this by adding FAIL mode check at the end of pool_preresume().

Cc: stable@vger.kernel.org
Fixes: da105ed5fd7e ("dm thin metadata: introduce dm_pool_abort_metadata")
Signed-off-by: Luo Meng 
Signed-off-by: Mike Snitzer

dm thin: Fix UAF in run_timer_softirq()

2022-11-30T18:29:34+00:00

When dm_resume() and dm_destroy() are concurrent, it will
lead to UAF, as follows:

 BUG: KASAN: use-after-free in __run_timers+0x173/0x710
 Write of size 8 at addr ffff88816d9490f0 by task swapper/0/0

 Call Trace:
  
  dump_stack_lvl+0x73/0x9f
  print_report.cold+0x132/0xaa2
  _raw_spin_lock_irqsave+0xcd/0x160
  __run_timers+0x173/0x710
  kasan_report+0xad/0x110
  __run_timers+0x173/0x710
  __asan_store8+0x9c/0x140
  __run_timers+0x173/0x710
  call_timer_fn+0x310/0x310
  pvclock_clocksource_read+0xfa/0x250
  kvm_clock_read+0x2c/0x70
  kvm_clock_get_cycles+0xd/0x20
  ktime_get+0x5c/0x110
  lapic_next_event+0x38/0x50
  clockevents_program_event+0xf1/0x1e0
  run_timer_softirq+0x49/0x90
  __do_softirq+0x16e/0x62c
  __irq_exit_rcu+0x1fa/0x270
  irq_exit_rcu+0x12/0x20
  sysvec_apic_timer_interrupt+0x8e/0xc0

One of the concurrency UAF can be shown as below:

        use                                  free
do_resume                           |
  __find_device_hash_cell           |
    dm_get                          |
      atomic_inc(&md->holders)      |
                                    | dm_destroy
                                    |   __dm_destroy
                                    |     if (!dm_suspended_md(md))
                                    |     atomic_read(&md->holders)
                                    |     msleep(1)
  dm_resume                         |
    __dm_resume                     |
      dm_table_resume_targets       |
        pool_resume                 |
          do_waker  #add delay work |
  dm_put                            |
    atomic_dec(&md->holders)        |
                                    |     dm_table_destroy
                                    |       pool_dtr
                                    |         __pool_dec
                                    |           __pool_destroy
                                    |             destroy_workqueue
                                    |             kfree(pool) # free pool
        time out
__do_softirq
  run_timer_softirq # pool has already been freed

This can be easily reproduced using:
  1. create thin-pool
  2. dmsetup suspend pool
  3. dmsetup resume pool
  4. dmsetup remove_all # Concurrent with 3

The root cause of this UAF bug is that dm_resume() adds timer after
dm_destroy() skips cancelling the timer because of suspend status.
After timeout, it will call run_timer_softirq(), however pool has
already been freed. The concurrency UAF bug will happen.

Therefore, cancelling timer again in __pool_destroy().

Cc: stable@vger.kernel.org
Fixes: 991d9fa02da0d ("dm: add thin provisioning target")
Signed-off-by: Luo Meng 
Signed-off-by: Mike Snitzer

dm thin: fix use-after-free crash in dm_sm_register_threshold_callback

2022-07-15T22:09:14+00:00

Fault inject on pool metadata device reports:
  BUG: KASAN: use-after-free in dm_pool_register_metadata_threshold+0x40/0x80
  Read of size 8 at addr ffff8881b9d50068 by task dmsetup/950

  CPU: 7 PID: 950 Comm: dmsetup Tainted: G        W         5.19.0-rc6 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
  Call Trace:
   
   dump_stack_lvl+0x34/0x44
   print_address_description.constprop.0.cold+0xeb/0x3f4
   kasan_report.cold+0xe6/0x147
   dm_pool_register_metadata_threshold+0x40/0x80
   pool_ctr+0xa0a/0x1150
   dm_table_add_target+0x2c8/0x640
   table_load+0x1fd/0x430
   ctl_ioctl+0x2c4/0x5a0
   dm_ctl_ioctl+0xa/0x10
   __x64_sys_ioctl+0xb3/0xd0
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

This can be easily reproduced using:
  echo offline > /sys/block/sda/device/state
  dd if=/dev/zero of=/dev/mapper/thin bs=4k count=10
  dmsetup load pool --table "0 20971520 thin-pool /dev/sda /dev/sdb 128 0 0"

If a metadata commit fails, the transaction will be aborted and the
metadata space maps will be destroyed. If a DM table reload then
happens for this failed thin-pool, a use-after-free will occur in
dm_sm_register_threshold_callback (called from
dm_pool_register_metadata_threshold).

Fix this by in dm_pool_register_metadata_threshold() by returning the
-EINVAL error if the thin-pool is in fail mode. Also fail pool_ctr()
with a new error message: "Error registering metadata threshold".

Fixes: ac8c3f3df65e4 ("dm thin: generate event when metadata threshold passed")
Cc: stable@vger.kernel.org
Reported-by: Hulk Robot 
Signed-off-by: Luo Meng 
Signed-off-by: Mike Snitzer

block: decouple REQ_OP_SECURE_ERASE from REQ_OP_DISCARD

2022-04-18T01:49:59+00:00

Secure erase is a very different operation from discard in that it is
a data integrity operation vs hint.  Fully split the limits and helper
infrastructure to make the separation more clear.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Acked-by: Christoph Böhmwalder  [drbd]
Acked-by: Ryusuke Konishi  [nifs2]
Acked-by: Jaegeuk Kim  [f2fs]
Acked-by: Coly Li  [bcache]
Acked-by: David Sterba  [btrfs]
Acked-by: Chao Yu 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220415045258.199825-27-hch@lst.de
Signed-off-by: Jens Axboe

block: remove QUEUE_FLAG_DISCARD

2022-04-18T01:49:59+00:00

Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Acked-by: Christoph Böhmwalder  [drbd]
Acked-by: Jan Höppner  [s390]
Acked-by: Coly Li  [bcache]
Acked-by: David Sterba  [btrfs]
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe