linux-stable.git/drivers/md, branch linux-6.5.y

dm-verity: don't use blocking calls from tasklets

2023-11-28T17:15:14+00:00

commit 28f07f2ab4b3a2714f1fefcc58ada4bcc195f806 upstream.

The commit 5721d4e5a9cd enhanced dm-verity, so that it can verify blocks
from tasklets rather than from workqueues. This reportedly improves
performance significantly.

However, dm-verity was using the flag CRYPTO_TFM_REQ_MAY_SLEEP from
tasklets which resulted in warnings about sleeping function being called
from non-sleeping context.

BUG: sleeping function called from invalid context at crypto/internal.h:206
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 14, name: ksoftirqd/0
preempt_count: 100, expected: 0
RCU nest depth: 0, expected: 0
CPU: 0 PID: 14 Comm: ksoftirqd/0 Tainted: G        W 6.7.0-rc1 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
 
 dump_stack_lvl+0x32/0x50
 __might_resched+0x110/0x160
 crypto_hash_walk_done+0x54/0xb0
 shash_ahash_update+0x51/0x60
 verity_hash_update.isra.0+0x4a/0x130 [dm_verity]
 verity_verify_io+0x165/0x550 [dm_verity]
 ? free_unref_page+0xdf/0x170
 ? psi_group_change+0x113/0x390
 verity_tasklet+0xd/0x70 [dm_verity]
 tasklet_action_common.isra.0+0xb3/0xc0
 __do_softirq+0xaf/0x1ec
 ? smpboot_thread_fn+0x1d/0x200
 ? sort_range+0x20/0x20
 run_ksoftirqd+0x15/0x30
 smpboot_thread_fn+0xed/0x200
 kthread+0xdc/0x110
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x28/0x40
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork_asm+0x11/0x20
 

This commit fixes dm-verity so that it doesn't use the flags
CRYPTO_TFM_REQ_MAY_SLEEP and CRYPTO_TFM_REQ_MAY_BACKLOG from tasklets. The
crypto API would do GFP_ATOMIC allocation instead, it could return -ENOMEM
and we catch -ENOMEM in verity_tasklet and requeue the request to the
workqueue.

Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org	# v6.0+
Fixes: 5721d4e5a9cd ("dm verity: Add optional "try_verify_in_tasklet" feature")
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm-bufio: fix no-sleep mode

2023-11-28T17:15:14+00:00

commit 2a695062a5a42aead8c539a344168d4806b3fda2 upstream.

dm-bufio has a no-sleep mode. When activated (with the
DM_BUFIO_CLIENT_NO_SLEEP flag), the bufio client is read-only and we
could call dm_bufio_get from tasklets. This is used by dm-verity.

Unfortunately, commit 450e8dee51aa ("dm bufio: improve concurrent IO
performance") broke this and the kernel would warn that cache_get()
was calling down_read() from no-sleeping context. The bug can be
reproduced by using "veritysetup open" with the "--use-tasklets"
flag.

This commit fixes dm-bufio, so that the tasklet mode works again, by
expanding use of the 'no_sleep_enabled' static_key to conditionally
use either a rw_semaphore or rwlock_t (which are colocated in the
buffer_tree structure using a union).

Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org	# v6.4
Fixes: 450e8dee51aa ("dm bufio: improve concurrent IO performance")
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm crypt: account large pages in cc->n_allocated_pages

2023-11-28T17:15:01+00:00

commit 9793c269da6cd339757de6ba5b2c8681b54c99af upstream.

The commit 5054e778fcd9c ("dm crypt: allocate compound pages if
possible") changed dm-crypt to use compound pages to improve
performance. Unfortunately, there was an oversight: the allocation of
compound pages was not accounted at all. Normal pages are accounted in
a percpu counter cc->n_allocated_pages and dm-crypt is limited to
allocate at most 2% of memory. Because compound pages were not
accounted at all, dm-crypt could allocate memory over the 2% limit.

Fix this by adding the accounting of compound pages, so that memory
consumption of dm-crypt is properly limited.

Signed-off-by: Mikulas Patocka 
Fixes: 5054e778fcd9c ("dm crypt: allocate compound pages if possible")
Cc: stable@vger.kernel.org	# v6.5+
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

md: don't rely on 'mddev->pers' to be set in mddev_suspend()

2023-11-28T17:14:44+00:00

[ Upstream commit b721e7885eb242aa2459ee66bb42ceef1bcf0f0c ]

'active_io' used to be initialized while the array is running, and
'mddev->pers' is set while the array is running as well. Hence caller
must hold 'reconfig_mutex' and guarantee 'mddev->pers' is set before
calling mddev_suspend().

Now that 'active_io' is initialized when mddev is allocated, such
restriction doesn't exist anymore. In the meantime, follow up patches
will refactor mddev_suspend(), hence add checking for 'mddev->pers' to
prevent null-ptr-deref.

Signed-off-by: Yu Kuai 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/20230825030956.1527023-4-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin

dm crypt: Fix reqsize in crypt_iv_eboiv_gen

2023-10-19T21:10:56+00:00

commit 152d0bcdf1efcb54a4fa20f694e9c7bbb6d06cbf upstream.

A skcipher_request object is made up of struct skcipher_request
followed by a variable-sized trailer.  The allocation of the
skcipher_request and IV in crypt_iv_eboiv_gen is missing the
memory for struct skcipher_request.  Fix it by adding it to
reqsize.

Fixes: e3023094dffb ("dm crypt: Avoid using MAX_CIPHER_BLOCKSIZE")
Cc:  #6.5+
Reported-by: Tatu Heikkilä 
Reviewed-by: Mike Snitzer 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

dm zoned: free dmz->ddev array in dmz_put_zoned_devices

2023-10-10T20:03:04+00:00

commit 9850ccd5dd88075b2b7fd28d96299d5535f58cc5 upstream.

Commit 4dba12881f88 ("dm zoned: support arbitrary number of devices")
made the pointers to additional zoned devices to be stored in a
dynamically allocated dmz->ddev array. However, this array is not freed.

Rename dmz_put_zoned_device to dmz_put_zoned_devices and fix it to
free the dmz->ddev array when cleaning up zoned device information.
Remove NULL assignment for all dmz->ddev elements and just free the
dmz->ddev array instead.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 4dba12881f88 ("dm zoned: support arbitrary number of devices")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

md/raid5: release batch_last before waiting for another stripe_head

2023-10-10T20:02:56+00:00

commit 2fd7b0f6d5ad655b1d947d3acdd82f687c31465e upstream.

When raid5_get_active_stripe is called with a ctx containing a stripe_head in
its batch_last pointer, it can cause a deadlock if the task sleeps waiting on
another stripe_head to become available. The stripe_head held by batch_last
can be blocking the advancement of other stripe_heads, leading to no
stripe_heads being released so raid5_get_active_stripe waits forever.

Like with the quiesce state handling earlier in the function, batch_last
needs to be released by raid5_get_active_stripe before it waits for another
stripe_head.

Fixes: 3312e6c887fe ("md/raid5: Keep a reference to last stripe_head for batch")
Cc: stable@vger.kernel.org # v6.0+
Signed-off-by: David Jeffery 
Reviewed-by: Logan Gunthorpe 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/20231002183422.13047-1-djeffery@redhat.com
Signed-off-by: Greg Kroah-Hartman

dm: fix a race condition in retrieve_deps

2023-09-23T09:14:35+00:00

commit f6007dce0cd35d634d9be91ef3515a6385dcee16 upstream.

There's a race condition in the multipath target when retrieve_deps
races with multipath_message calling dm_get_device and dm_put_device.
retrieve_deps walks the list of open devices without holding any lock
but multipath may add or remove devices to the list while it is
running. The end result may be memory corruption or use-after-free
memory access.

See this description of a UAF with multipath_message():
https://listman.redhat.com/archives/dm-devel/2022-October/052373.html

Fix this bug by introducing a new rw semaphore "devices_lock". We grab
devices_lock for read in retrieve_deps and we grab it for write in
dm_get_device and dm_put_device.

Reported-by: Luo Meng 
Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org
Tested-by: Li Lingfeng 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm: don't attempt to queue IO under RCU protection

2023-09-23T09:14:35+00:00

commit a9ce385344f916cd1c36a33905e564f5581beae9 upstream.

dm looks up the table for IO based on the request type, with an
assumption that if the request is marked REQ_NOWAIT, it's fine to
attempt to submit that IO while under RCU read lock protection. This
is not OK, as REQ_NOWAIT just means that we should not be sleeping
waiting on other IO, it does not mean that we can't potentially
schedule.

A simple test case demonstrates this quite nicely:

int main(int argc, char *argv[])
{
        struct iovec iov;
        int fd;

        fd = open("/dev/dm-0", O_RDONLY | O_DIRECT);
        posix_memalign(&iov.iov_base, 4096, 4096);
        iov.iov_len = 4096;
        preadv2(fd, &iov, 1, 0, RWF_NOWAIT);
        return 0;
}

which will instantly spew:

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5580, name: dm-nowait
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
CPU: 7 PID: 5580 Comm: dm-nowait Not tainted 6.6.0-rc1-g39956d2dcd81 #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 
 dump_stack_lvl+0x11d/0x1b0
 __might_resched+0x3c3/0x5e0
 ? preempt_count_sub+0x150/0x150
 mempool_alloc+0x1e2/0x390
 ? mempool_resize+0x7d0/0x7d0
 ? lock_sync+0x190/0x190
 ? lock_release+0x4b7/0x670
 ? internal_get_user_pages_fast+0x868/0x2d40
 bio_alloc_bioset+0x417/0x8c0
 ? bvec_alloc+0x200/0x200
 ? internal_get_user_pages_fast+0xb8c/0x2d40
 bio_alloc_clone+0x53/0x100
 dm_submit_bio+0x27f/0x1a20
 ? lock_release+0x4b7/0x670
 ? blk_try_enter_queue+0x1a0/0x4d0
 ? dm_dax_direct_access+0x260/0x260
 ? rcu_is_watching+0x12/0xb0
 ? blk_try_enter_queue+0x1cc/0x4d0
 __submit_bio+0x239/0x310
 ? __bio_queue_enter+0x700/0x700
 ? kvm_clock_get_cycles+0x40/0x60
 ? ktime_get+0x285/0x470
 submit_bio_noacct_nocheck+0x4d9/0xb80
 ? should_fail_request+0x80/0x80
 ? preempt_count_sub+0x150/0x150
 ? lock_release+0x4b7/0x670
 ? __bio_add_page+0x143/0x2d0
 ? iov_iter_revert+0x27/0x360
 submit_bio_noacct+0x53e/0x1b30
 submit_bio_wait+0x10a/0x230
 ? submit_bio_wait_endio+0x40/0x40
 __blkdev_direct_IO_simple+0x4f8/0x780
 ? blkdev_bio_end_io+0x4c0/0x4c0
 ? stack_trace_save+0x90/0xc0
 ? __bio_clone+0x3c0/0x3c0
 ? lock_release+0x4b7/0x670
 ? lock_sync+0x190/0x190
 ? atime_needs_update+0x3bf/0x7e0
 ? timestamp_truncate+0x21b/0x2d0
 ? inode_owner_or_capable+0x240/0x240
 blkdev_direct_IO.part.0+0x84a/0x1810
 ? rcu_is_watching+0x12/0xb0
 ? lock_release+0x4b7/0x670
 ? blkdev_read_iter+0x40d/0x530
 ? reacquire_held_locks+0x4e0/0x4e0
 ? __blkdev_direct_IO_simple+0x780/0x780
 ? rcu_is_watching+0x12/0xb0
 ? __mark_inode_dirty+0x297/0xd50
 ? preempt_count_add+0x72/0x140
 blkdev_read_iter+0x2a4/0x530
 do_iter_readv_writev+0x2f2/0x3c0
 ? generic_copy_file_range+0x1d0/0x1d0
 ? fsnotify_perm.part.0+0x25d/0x630
 ? security_file_permission+0xd8/0x100
 do_iter_read+0x31b/0x880
 ? import_iovec+0x10b/0x140
 vfs_readv+0x12d/0x1a0
 ? vfs_iter_read+0xb0/0xb0
 ? rcu_is_watching+0x12/0xb0
 ? rcu_is_watching+0x12/0xb0
 ? lock_release+0x4b7/0x670
 do_preadv+0x1b3/0x260
 ? do_readv+0x370/0x370
 __x64_sys_preadv2+0xef/0x150
 do_syscall_64+0x39/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5af41ad806
Code: 41 54 41 89 fc 55 44 89 c5 53 48 89 cb 48 83 ec 18 80 3d e4 dd 0d 00 00 74 7a 45 89 c1 49 89 ca 45 31 c0 b8 47 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 be 00 00 00 48 85 c0 79 4a 48 8b 0d da 55
RSP: 002b:00007ffd3145c7f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000147
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5af41ad806
RDX: 0000000000000001 RSI: 00007ffd3145c850 RDI: 0000000000000003
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffd3145c850 R14: 000055f5f0431dd8 R15: 0000000000000001
 

where in fact it is dm itself that attempts to allocate a bio clone with
GFP_NOIO under the rcu read lock, regardless of the request type.

Fix this by getting rid of the special casing for REQ_NOWAIT, and just
use the normal SRCU protected table lookup. Get rid of the bio based
table locking helpers at the same time, as they are now unused.

Cc: stable@vger.kernel.org
Fixes: 563a225c9fd2 ("dm: introduce dm_{get,put}_live_table_bio called from dm_submit_bio")
Signed-off-by: Jens Axboe 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

md: Put the right device in md_seq_next

2023-09-23T09:14:34+00:00

commit c8870379a21fbd9ad14ca36204ccfbe9d25def43 upstream.

If there are multiple arrays in system and one mddevice is marked
with MD_DELETED and md_seq_next() is called in the middle of removal
then it _get()s proper device but it may _put() deleted one. As a result,
active counter may never be zeroed for mddevice and it cannot
be removed.

Put the device which has been _get with previous md_seq_next() call.

Cc: stable@vger.kernel.org
Fixes: 12a6caf27324 ("md: only delete entries from all_mddevs when the disk is freed")
Reported-by: AceLan Kao 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217798
Cc: Yu Kuai 
Signed-off-by: Mariusz Tkaczyk 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/20230914152416.10819-1-mariusz.tkaczyk@linux.intel.com
Signed-off-by: Greg Kroah-Hartman