linux-stable.git/drivers/md, branch v4.9.321 Linux kernel stable tree dm era: commit metadata in postsuspend after worker stops 2022-07-02T14:17:14+00:00 Nikos Tsironis ntsironis@arrikto.com 2022-06-21T12:24:03+00:00 f550444427bb33ce9764fb911a8cb0622ff7b45b commit 9ae6e8b1c9bbf6874163d1243e393137313762b7 upstream. During postsuspend dm-era does the following: 1. Archives the current era 2. Commits the metadata, as part of the RPC call for archiving the current era 3. Stops the worker Until the worker stops, it might write to the metadata again. Moreover, these writes are not flushed to disk immediately, but are cached by the dm-bufio client, which writes them back asynchronously. As a result, the committed metadata of a suspended dm-era device might not be consistent with the in-core metadata. In some cases, this can result in the corruption of the on-disk metadata. Suppose the following sequence of events: 1. Load a new table, e.g. a snapshot-origin table, to a device with a dm-era table 2. Suspend the device 3. dm-era commits its metadata, but the worker does a few more metadata writes until it stops, as part of digesting an archived writeset 4. These writes are cached by the dm-bufio client 5. Load the dm-era table to another device. 6. The new instance of the dm-era target loads the committed, on-disk metadata, which don't include the extra writes done by the worker after the metadata commit. 7. Resume the new device 8. The new dm-era target instance starts using the metadata 9. Resume the original device 10. The destructor of the old dm-era target instance is called and destroys the dm-bufio client, which results in flushing the cached writes to disk 11. These writes might overwrite the writes done by the new dm-era instance, hence corrupting its metadata. Fix this by committing the metadata after the worker stops running. stop_worker uses flush_workqueue to flush the current work. However, the work item may re-queue itself and flush_workqueue doesn't wait for re-queued works to finish. This could result in the worker changing the metadata after they have been committed, or writing to the metadata concurrently with the commit in the postsuspend thread. Use drain_workqueue instead, which waits until the work and all re-queued works finish. Fixes: eec40579d8487 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9ae6e8b1c9bbf6874163d1243e393137313762b7 upstream.

During postsuspend dm-era does the following:

1. Archives the current era
2. Commits the metadata, as part of the RPC call for archiving the
   current era
3. Stops the worker

Until the worker stops, it might write to the metadata again. Moreover,
these writes are not flushed to disk immediately, but are cached by the
dm-bufio client, which writes them back asynchronously.

As a result, the committed metadata of a suspended dm-era device might
not be consistent with the in-core metadata.

In some cases, this can result in the corruption of the on-disk
metadata. Suppose the following sequence of events:

1. Load a new table, e.g. a snapshot-origin table, to a device with a
   dm-era table
2. Suspend the device
3. dm-era commits its metadata, but the worker does a few more metadata
   writes until it stops, as part of digesting an archived writeset
4. These writes are cached by the dm-bufio client
5. Load the dm-era table to another device.
6. The new instance of the dm-era target loads the committed, on-disk
   metadata, which don't include the extra writes done by the worker
   after the metadata commit.
7. Resume the new device
8. The new dm-era target instance starts using the metadata
9. Resume the original device
10. The destructor of the old dm-era target instance is called and
    destroys the dm-bufio client, which results in flushing the cached
    writes to disk
11. These writes might overwrite the writes done by the new dm-era
    instance, hence corrupting its metadata.

Fix this by committing the metadata after the worker stops running.

stop_worker uses flush_workqueue to flush the current work. However, the
work item may re-queue itself and flush_workqueue doesn't wait for
re-queued works to finish.

This could result in the worker changing the metadata after they have
been committed, or writing to the metadata concurrently with the commit
in the postsuspend thread.

Use drain_workqueue instead, which waits until the work and all
re-queued works finish.

Fixes: eec40579d8487 ("dm: add era target")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
md: protect md_unregister_thread from reentrancy 2022-06-14T14:52:40+00:00 Guoqing Jiang guoqing.jiang@cloud.ionos.com 2022-04-29T08:49:09+00:00 ac8fd53fa022d57b16393e8cc3ab2f80ad315d4a [ Upstream commit 1e267742283a4b5a8ca65755c44166be27e9aa0f ] Generally, the md_unregister_thread is called with reconfig_mutex, but raid_message in dm-raid doesn't hold reconfig_mutex to unregister thread, so md_unregister_thread can be called simulitaneously from two call sites in theory. Then after previous commit which remove the protection of reconfig_mutex for md_unregister_thread completely, the potential issue could be worse than before. Let's take pers_lock at the beginning of function to ensure reentrancy. Reported-by: Donald Buczek <buczek@molgen.mpg.de> Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1e267742283a4b5a8ca65755c44166be27e9aa0f ]

Generally, the md_unregister_thread is called with reconfig_mutex, but
raid_message in dm-raid doesn't hold reconfig_mutex to unregister thread,
so md_unregister_thread can be called simulitaneously from two call sites
in theory.

Then after previous commit which remove the protection of reconfig_mutex
for md_unregister_thread completely, the potential issue could be worse
than before.

Let's take pers_lock at the beginning of function to ensure reentrancy.

Reported-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
md: fix an incorrect NULL check in md_reload_sb 2022-06-14T14:52:35+00:00 Xiaomeng Tong xiam0nd.tong@gmail.com 2022-04-08T08:47:15+00:00 61751cdcd33b544d9c21855a4375fd30af6cf4ed commit 64c54d9244a4efe9bc6e9c98e13c4bbb8bb39083 upstream. The bug is here: if (!rdev || rdev->desc_nr != nr) { The list iterator value 'rdev' will *always* be set and non-NULL by rdev_for_each_rcu(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element found (In fact, it will be a bogus pointer to an invalid struct object containing the HEAD). Otherwise it will bypass the check and lead to invalid memory access passing the check. To fix the bug, use a new variable 'iter' as the list iterator, while using the original variable 'pdev' as a dedicated pointer to point to the found element. Cc: stable@vger.kernel.org Fixes: 70bcecdb1534 ("md-cluster: Improve md_reload_sb to be less error prone") Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 64c54d9244a4efe9bc6e9c98e13c4bbb8bb39083 upstream.

The bug is here:
	if (!rdev || rdev->desc_nr != nr) {

The list iterator value 'rdev' will *always* be set and non-NULL
by rdev_for_each_rcu(), so it is incorrect to assume that the
iterator value will be NULL if the list is empty or no element
found (In fact, it will be a bogus pointer to an invalid struct
object containing the HEAD). Otherwise it will bypass the check
and lead to invalid memory access passing the check.

To fix the bug, use a new variable 'iter' as the list iterator,
while using the original variable 'pdev' as a dedicated pointer to
point to the found element.

Cc: stable@vger.kernel.org
Fixes: 70bcecdb1534 ("md-cluster: Improve md_reload_sb to be less error prone")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
md: fix an incorrect NULL check in does_sb_need_changing 2022-06-14T14:52:35+00:00 Xiaomeng Tong xiam0nd.tong@gmail.com 2022-04-08T08:37:28+00:00 30da8cb0e506e71e901476b997a5acf79f80bf46 commit fc8738343eefc4ea8afb6122826dea48eacde514 upstream. The bug is here: if (!rdev) The list iterator value 'rdev' will *always* be set and non-NULL by rdev_for_each(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element found. Otherwise it will bypass the NULL check and lead to invalid memory access passing the check. To fix the bug, use a new variable 'iter' as the list iterator, while using the original variable 'rdev' as a dedicated pointer to point to the found element. Cc: stable@vger.kernel.org Fixes: 2aa82191ac36 ("md-cluster: Perform a lazy update") Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fc8738343eefc4ea8afb6122826dea48eacde514 upstream.

The bug is here:
	if (!rdev)

The list iterator value 'rdev' will *always* be set and non-NULL
by rdev_for_each(), so it is incorrect to assume that the iterator
value will be NULL if the list is empty or no element found.
Otherwise it will bypass the NULL check and lead to invalid memory
access passing the check.

To fix the bug, use a new variable 'iter' as the list iterator,
while using the original variable 'rdev' as a dedicated pointer to
point to the found element.

Cc: stable@vger.kernel.org
Fixes: 2aa82191ac36 ("md-cluster: Perform a lazy update")
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dm verity: set DM_TARGET_IMMUTABLE feature flag 2022-06-06T06:19:46+00:00 Sarthak Kukreti sarthakkukreti@google.com 2022-05-31T19:56:40+00:00 27798cca4e54fe9c390396c4cc655480f827bbd5 commit 4caae58406f8ceb741603eee460d79bacca9b1b5 upstream. The device-mapper framework provides a mechanism to mark targets as immutable (and hence fail table reloads that try to change the target type). Add the DM_TARGET_IMMUTABLE flag to the dm-verity target's feature flags to prevent switching the verity target with a different target type. Fixes: a4ffc152198e ("dm: add verity target") Cc: stable@vger.kernel.org Signed-off-by: Sarthak Kukreti <sarthakkukreti@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4caae58406f8ceb741603eee460d79bacca9b1b5 upstream.

The device-mapper framework provides a mechanism to mark targets as
immutable (and hence fail table reloads that try to change the target
type). Add the DM_TARGET_IMMUTABLE flag to the dm-verity target's
feature flags to prevent switching the verity target with a different
target type.

Fixes: a4ffc152198e ("dm: add verity target")
Cc: stable@vger.kernel.org
Signed-off-by: Sarthak Kukreti <sarthakkukreti@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dm stats: add cond_resched when looping over entries 2022-06-06T06:19:46+00:00 Mikulas Patocka mpatocka@redhat.com 2022-04-24T20:43:00+00:00 6adce527fe86f0156ea853742c951c01b1f0d6fc commit bfe2b0146c4d0230b68f5c71a64380ff8d361f8b upstream. dm-stats can be used with a very large number of entries (it is only limited by 1/4 of total system memory), so add rescheduling points to the loops that iterate over the entries. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bfe2b0146c4d0230b68f5c71a64380ff8d361f8b upstream.

dm-stats can be used with a very large number of entries (it is only
limited by 1/4 of total system memory), so add rescheduling points to
the loops that iterate over the entries.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dm crypt: make printing of the key constant-time 2022-06-06T06:19:46+00:00 Mikulas Patocka mpatocka@redhat.com 2022-04-25T12:53:29+00:00 49e2a292b3d63d1971f80a929fc806702074559a commit 567dd8f34560fa221a6343729474536aa7ede4fd upstream. The device mapper dm-crypt target is using scnprintf("%02x", cc->key[i]) to report the current key to userspace. However, this is not a constant-time operation and it may leak information about the key via timing, via cache access patterns or via the branch predictor. Change dm-crypt's key printing to use "%c" instead of "%02x". Also introduce hex2asc() that carefully avoids any branching or memory accesses when converting a number in the range 0 ... 15 to an ascii character. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 567dd8f34560fa221a6343729474536aa7ede4fd upstream.

The device mapper dm-crypt target is using scnprintf("%02x", cc->key[i]) to
report the current key to userspace. However, this is not a constant-time
operation and it may leak information about the key via timing, via cache
access patterns or via the branch predictor.

Change dm-crypt's key printing to use "%c" instead of "%02x". Also
introduce hex2asc() that carefully avoids any branching or memory
accesses when converting a number in the range 0 ... 15 to an ascii
character.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dm: interlock pending dm_io and dm_wait_for_bios_completion 2022-05-12T10:14:58+00:00 Mike Snitzer snitzer@redhat.com 2022-02-18T04:40:02+00:00 7bb369096d1711d28cda36853f8e1920bbe3e86d commit 9f6dc633761006f974701d4c88da71ab68670749 upstream. Commit d208b89401e0 ("dm: fix mempool NULL pointer race when completing IO") didn't go far enough. When bio_end_io_acct ends the count of in-flight I/Os may reach zero and the DM device may be suspended. There is a possibility that the suspend races with dm_stats_account_io. Fix this by adding percpu "pending_io" counters to track outstanding dm_io. Move kicking of suspend queue to dm_io_dec_pending(). Also, rename md_in_flight_bios() to dm_in_flight_bios() and update it to iterate all pending_io counters. Fixes: d208b89401e0 ("dm: fix mempool NULL pointer race when completing IO") Cc: stable@vger.kernel.org Co-developed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9f6dc633761006f974701d4c88da71ab68670749 upstream.

Commit d208b89401e0 ("dm: fix mempool NULL pointer race when
completing IO") didn't go far enough.

When bio_end_io_acct ends the count of in-flight I/Os may reach zero
and the DM device may be suspended. There is a possibility that the
suspend races with dm_stats_account_io.

Fix this by adding percpu "pending_io" counters to track outstanding
dm_io. Move kicking of suspend queue to dm_io_dec_pending(). Also,
rename md_in_flight_bios() to dm_in_flight_bios() and update it to
iterate all pending_io counters.

Fixes: d208b89401e0 ("dm: fix mempool NULL pointer race when completing IO")
Cc: stable@vger.kernel.org
Co-developed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dm: fix mempool NULL pointer race when completing IO 2022-05-12T10:14:58+00:00 Jiazi Li jqqlijiazi@gmail.com 2021-09-29T11:59:28+00:00 9fb7cd5c7fef0f1c982e3cd27745a0dec260eaed commit d208b89401e073de986dc891037c5a668f5d5d95 upstream. dm_io_dec_pending() calls end_io_acct() first and will then dec md in-flight pending count. But if a task is swapping DM table at same time this can result in a crash due to mempool->elements being NULL: task1 task2 do_resume ->do_suspend ->dm_wait_for_completion bio_endio ->clone_endio ->dm_io_dec_pending ->end_io_acct ->wakeup task1 ->dm_swap_table ->__bind ->__bind_mempools ->bioset_exit ->mempool_exit ->free_io [ 67.330330] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 ...... [ 67.330494] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 67.330510] pc : mempool_free+0x70/0xa0 [ 67.330515] lr : mempool_free+0x4c/0xa0 [ 67.330520] sp : ffffff8008013b20 [ 67.330524] x29: ffffff8008013b20 x28: 0000000000000004 [ 67.330530] x27: ffffffa8c2ff40a0 x26: 00000000ffff1cc8 [ 67.330535] x25: 0000000000000000 x24: ffffffdada34c800 [ 67.330541] x23: 0000000000000000 x22: ffffffdada34c800 [ 67.330547] x21: 00000000ffff1cc8 x20: ffffffd9a1304d80 [ 67.330552] x19: ffffffdada34c970 x18: 000000b312625d9c [ 67.330558] x17: 00000000002dcfbf x16: 00000000000006dd [ 67.330563] x15: 000000000093b41e x14: 0000000000000010 [ 67.330569] x13: 0000000000007f7a x12: 0000000034155555 [ 67.330574] x11: 0000000000000001 x10: 0000000000000001 [ 67.330579] x9 : 0000000000000000 x8 : 0000000000000000 [ 67.330585] x7 : 0000000000000000 x6 : ffffff80148b5c1a [ 67.330590] x5 : ffffff8008013ae0 x4 : 0000000000000001 [ 67.330596] x3 : ffffff80080139c8 x2 : ffffff801083bab8 [ 67.330601] x1 : 0000000000000000 x0 : ffffffdada34c970 [ 67.330609] Call trace: [ 67.330616] mempool_free+0x70/0xa0 [ 67.330627] bio_put+0xf8/0x110 [ 67.330638] dec_pending+0x13c/0x230 [ 67.330644] clone_endio+0x90/0x180 [ 67.330649] bio_endio+0x198/0x1b8 [ 67.330655] dec_pending+0x190/0x230 [ 67.330660] clone_endio+0x90/0x180 [ 67.330665] bio_endio+0x198/0x1b8 [ 67.330673] blk_update_request+0x214/0x428 [ 67.330683] scsi_end_request+0x2c/0x300 [ 67.330688] scsi_io_completion+0xa0/0x710 [ 67.330695] scsi_finish_command+0xd8/0x110 [ 67.330700] scsi_softirq_done+0x114/0x148 [ 67.330708] blk_done_softirq+0x74/0xd0 [ 67.330716] __do_softirq+0x18c/0x374 [ 67.330724] irq_exit+0xb4/0xb8 [ 67.330732] __handle_domain_irq+0x84/0xc0 [ 67.330737] gic_handle_irq+0x148/0x1b0 [ 67.330744] el1_irq+0xe8/0x190 [ 67.330753] lpm_cpuidle_enter+0x4f8/0x538 [ 67.330759] cpuidle_enter_state+0x1fc/0x398 [ 67.330764] cpuidle_enter+0x18/0x20 [ 67.330772] do_idle+0x1b4/0x290 [ 67.330778] cpu_startup_entry+0x20/0x28 [ 67.330786] secondary_start_kernel+0x160/0x170 Fix this by: 1) Establishing pointers to 'struct dm_io' members in dm_io_dec_pending() so that they may be passed into end_io_acct() _after_ free_io() is called. 2) Moving end_io_acct() after free_io(). Cc: stable@vger.kernel.org Signed-off-by: Jiazi Li <lijiazi@xiaomi.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d208b89401e073de986dc891037c5a668f5d5d95 upstream.

dm_io_dec_pending() calls end_io_acct() first and will then dec md
in-flight pending count. But if a task is swapping DM table at same
time this can result in a crash due to mempool->elements being NULL:

task1                             task2
do_resume
 ->do_suspend
  ->dm_wait_for_completion
                                  bio_endio
				   ->clone_endio
				    ->dm_io_dec_pending
				     ->end_io_acct
				      ->wakeup task1
 ->dm_swap_table
  ->__bind
   ->__bind_mempools
    ->bioset_exit
     ->mempool_exit
                                     ->free_io

[ 67.330330] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000000
......
[ 67.330494] pstate: 80400085 (Nzcv daIf +PAN -UAO)
[ 67.330510] pc : mempool_free+0x70/0xa0
[ 67.330515] lr : mempool_free+0x4c/0xa0
[ 67.330520] sp : ffffff8008013b20
[ 67.330524] x29: ffffff8008013b20 x28: 0000000000000004
[ 67.330530] x27: ffffffa8c2ff40a0 x26: 00000000ffff1cc8
[ 67.330535] x25: 0000000000000000 x24: ffffffdada34c800
[ 67.330541] x23: 0000000000000000 x22: ffffffdada34c800
[ 67.330547] x21: 00000000ffff1cc8 x20: ffffffd9a1304d80
[ 67.330552] x19: ffffffdada34c970 x18: 000000b312625d9c
[ 67.330558] x17: 00000000002dcfbf x16: 00000000000006dd
[ 67.330563] x15: 000000000093b41e x14: 0000000000000010
[ 67.330569] x13: 0000000000007f7a x12: 0000000034155555
[ 67.330574] x11: 0000000000000001 x10: 0000000000000001
[ 67.330579] x9 : 0000000000000000 x8 : 0000000000000000
[ 67.330585] x7 : 0000000000000000 x6 : ffffff80148b5c1a
[ 67.330590] x5 : ffffff8008013ae0 x4 : 0000000000000001
[ 67.330596] x3 : ffffff80080139c8 x2 : ffffff801083bab8
[ 67.330601] x1 : 0000000000000000 x0 : ffffffdada34c970
[ 67.330609] Call trace:
[ 67.330616] mempool_free+0x70/0xa0
[ 67.330627] bio_put+0xf8/0x110
[ 67.330638] dec_pending+0x13c/0x230
[ 67.330644] clone_endio+0x90/0x180
[ 67.330649] bio_endio+0x198/0x1b8
[ 67.330655] dec_pending+0x190/0x230
[ 67.330660] clone_endio+0x90/0x180
[ 67.330665] bio_endio+0x198/0x1b8
[ 67.330673] blk_update_request+0x214/0x428
[ 67.330683] scsi_end_request+0x2c/0x300
[ 67.330688] scsi_io_completion+0xa0/0x710
[ 67.330695] scsi_finish_command+0xd8/0x110
[ 67.330700] scsi_softirq_done+0x114/0x148
[ 67.330708] blk_done_softirq+0x74/0xd0
[ 67.330716] __do_softirq+0x18c/0x374
[ 67.330724] irq_exit+0xb4/0xb8
[ 67.330732] __handle_domain_irq+0x84/0xc0
[ 67.330737] gic_handle_irq+0x148/0x1b0
[ 67.330744] el1_irq+0xe8/0x190
[ 67.330753] lpm_cpuidle_enter+0x4f8/0x538
[ 67.330759] cpuidle_enter_state+0x1fc/0x398
[ 67.330764] cpuidle_enter+0x18/0x20
[ 67.330772] do_idle+0x1b4/0x290
[ 67.330778] cpu_startup_entry+0x20/0x28
[ 67.330786] secondary_start_kernel+0x160/0x170

Fix this by:
1) Establishing pointers to 'struct dm_io' members in
dm_io_dec_pending() so that they may be passed into end_io_acct()
_after_ free_io() is called.
2) Moving end_io_acct() after free_io().

Cc: stable@vger.kernel.org
Signed-off-by: Jiazi Li <lijiazi@xiaomi.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dm ioctl: prevent potential spectre v1 gadget 2022-04-20T07:06:42+00:00 Jordy Zomer jordy@jordyzomer.github.io 2022-01-29T14:58:39+00:00 76c94651005f58885facf9c973007f5ea01ab01f [ Upstream commit cd9c88da171a62c4b0f1c70e50c75845969fbc18 ] It appears like cmd could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. Signed-off-by: Jordy Zomer <jordy@pwning.systems> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit cd9c88da171a62c4b0f1c70e50c75845969fbc18 ]

It appears like cmd could be a Spectre v1 gadget as it's supplied by a
user and used as an array index. Prevent the contents of kernel memory
from being leaked to userspace via speculative execution by using
array_index_nospec.

Signed-off-by: Jordy Zomer <jordy@pwning.systems>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>