======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.477/6020 is trying to acquire lock:
ffff0000c314d938 ((wq_completion)md_misc){+.+.}-{0:0}, at: __flush_workqueue+0x108/0x1064 kernel/workqueue.c:2813

but task is already holding lock:
ffff0000d0028328 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: mddev_lock_nointr drivers/md/md.h:585 [inline]
ffff0000d0028328 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: raid_dtr+0x48/0x70 drivers/md/dm-raid.c:3318

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&mddev->reconfig_mutex){+.+.}-{3:3}:
       __mutex_lock_common+0x1a0/0x1f88 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_interruptible_nested+0x38/0x44 kernel/locking/mutex.c:821
       mddev_lock drivers/md/md.h:577 [inline]
       array_state_store+0x28c/0x944 drivers/md/md.c:4480
       md_attr_store+0x168/0x234 drivers/md/md.c:5634
       sysfs_kf_write+0x1f8/0x274 fs/sysfs/file.c:140
       kernfs_fop_write_iter+0x390/0x4b4 fs/kernfs/file.c:352
       call_write_iter include/linux/fs.h:2271 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x3c8/0x7c8 fs/read_write.c:584
       ksys_write+0x12c/0x228 fs/read_write.c:637
       __do_sys_write fs/read_write.c:649 [inline]
       __se_sys_write fs/read_write.c:646 [inline]
       __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
       do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
       el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:589

-> #2 (kn->active#70){++++}-{0:0}:
       kernfs_drain+0x294/0x5f8 fs/kernfs/dir.c:499
       __kernfs_remove+0x3c0/0x654 fs/kernfs/dir.c:1461
       kernfs_remove_by_name_ns+0xe4/0x184 fs/kernfs/dir.c:1667
       kernfs_remove_by_name include/linux/kernfs.h:622 [inline]
       remove_files fs/sysfs/group.c:28 [inline]
       sysfs_remove_group+0xf4/0x278 fs/sysfs/group.c:288
       sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:312
       __kobject_del+0x94/0x2d4 lib/kobject.c:587
       kobject_cleanup lib/kobject.c:672 [inline]
       kobject_release lib/kobject.c:712 [inline]
       kref_put include/linux/kref.h:65 [inline]
       kobject_put+0x2c0/0x41c lib/kobject.c:729
       mddev_delayed_delete+0x20/0x30 drivers/md/md.c:5668
       process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
       worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
       kthread+0x254/0x2e0 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854

-> #1 ((work_completion)(&mddev->del_work)){+.+.}-{0:0}:
       process_one_work+0x710/0x13bc kernel/workqueue.c:2268
       worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
       kthread+0x254/0x2e0 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854

-> #0 ((wq_completion)md_misc){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3162 [inline]
       check_prevs_add kernel/locking/lockdep.c:3281 [inline]
       validate_chain kernel/locking/lockdep.c:3897 [inline]
       __lock_acquire+0x3504/0x7280 kernel/locking/lockdep.c:5171
       lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790
       __flush_workqueue+0x134/0x1064 kernel/workqueue.c:2816
       __md_stop+0x190/0x334 drivers/md/md.c:6363
       md_stop+0x88/0xd4 drivers/md/md.c:6389
       raid_dtr+0x50/0x70 drivers/md/dm-raid.c:3319
       dm_table_destroy+0x14c/0x3b0 drivers/md/dm-table.c:196
       table_load+0x540/0x690 drivers/md/dm-ioctl.c:1548
       ctl_ioctl drivers/md/dm-ioctl.c:2070 [inline]
       dm_ctl_ioctl+0xaac/0xf1c drivers/md/dm-ioctl.c:2092
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl fs/ioctl.c:856 [inline]
       __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
       do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
       el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:589

other info that might help us debug this:

Chain exists of:
  (wq_completion)md_misc --> kn->active#70 --> &mddev->reconfig_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mddev->reconfig_mutex);
                               lock(kn->active#70);
                               lock(&mddev->reconfig_mutex);
  lock((wq_completion)md_misc);

 *** DEADLOCK ***

1 lock held by syz.3.477/6020:
 #0: ffff0000d0028328 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: mddev_lock_nointr drivers/md/md.h:585 [inline]
 #0: ffff0000d0028328 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: raid_dtr+0x48/0x70 drivers/md/dm-raid.c:3318

stack backtrace:
CPU: 1 PID: 6020 Comm: syz.3.477 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2088
 check_noncircular+0x290/0x370 kernel/locking/lockdep.c:2215
 check_prev_add kernel/locking/lockdep.c:3162 [inline]
 check_prevs_add kernel/locking/lockdep.c:3281 [inline]
 validate_chain kernel/locking/lockdep.c:3897 [inline]
 __lock_acquire+0x3504/0x7280 kernel/locking/lockdep.c:5171
 lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790
 __flush_workqueue+0x134/0x1064 kernel/workqueue.c:2816
 __md_stop+0x190/0x334 drivers/md/md.c:6363
 md_stop+0x88/0xd4 drivers/md/md.c:6389
 raid_dtr+0x50/0x70 drivers/md/dm-raid.c:3319
 dm_table_destroy+0x14c/0x3b0 drivers/md/dm-table.c:196
 table_load+0x540/0x690 drivers/md/dm-ioctl.c:1548
 ctl_ioctl drivers/md/dm-ioctl.c:2070 [inline]
 dm_ctl_ioctl+0xaac/0xf1c drivers/md/dm-ioctl.c:2092
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:589