======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.8.598/8400 is trying to acquire lock:
ffff88801e79e948 ((wq_completion)md_misc){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x9c/0x1c0 kernel/workqueue.c:4272

but task is already holding lock:
ffffffff90be60e0 (major_names_lock){+.+.}-{4:4}, at: blk_probe_dev+0x28/0x1e0 block/genhd.c:885

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (major_names_lock){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19f/0x1c10 kernel/locking/mutex.c:821
       blk_probe_dev+0x28/0x1e0 block/genhd.c:885
       blk_request_module+0x16/0xc0 block/genhd.c:901
       blkdev_get_no_open+0x9b/0xf0 block/bdev.c:870
       bdev_file_open_by_dev block/bdev.c:1091 [inline]
       bdev_file_open_by_dev+0x70/0x210 block/bdev.c:1079
       md_import_device+0x120/0x360 drivers/md/md.c:3861
       new_dev_store+0x42a/0x8e0 drivers/md/md.c:4882
       md_attr_store+0x1c5/0x330 drivers/md/md.c:6177
       sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
       kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x6af/0x1040 fs/read_write.c:687
       ksys_write+0x12a/0x250 fs/read_write.c:739
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x123/0x7b0 arch/x86/entry/syscall_64.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&mddev->reconfig_mutex){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19f/0x1c10 kernel/locking/mutex.c:821
       mddev_lock_nointr drivers/md/md.h:734 [inline]
       md_start_sync+0xc4/0xea0 drivers/md/md.c:10301
       process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
       process_scheduled_works kernel/workqueue.c:3578 [inline]
       worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
       kthread+0x373/0x450 kernel/kthread.c:436
       ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #1 ((work_completion)(&mddev->sync_work)){+.+.}-{0:0}:
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
       process_one_work+0xa32/0x1b10 kernel/workqueue.c:3471
       process_scheduled_works kernel/workqueue.c:3578 [inline]
       worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
       kthread+0x373/0x450 kernel/kthread.c:436
       ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 ((wq_completion)md_misc){+.+.}-{0:0}:
       check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
       touch_wq_lockdep_map+0xad/0x1c0 kernel/workqueue.c:4272
       __flush_workqueue+0x131/0x1200 kernel/workqueue.c:4314
       md_alloc+0x30/0x10c0 drivers/md/md.c:6353
       md_alloc_and_put drivers/md/md.c:6452 [inline]
       md_probe drivers/md/md.c:6468 [inline]
       md_probe+0x73/0xf0 drivers/md/md.c:6463
       blk_probe_dev+0x149/0x1e0 block/genhd.c:888
       blk_request_module+0x16/0xc0 block/genhd.c:901
       blkdev_get_no_open+0x9b/0xf0 block/bdev.c:870
       blkdev_open+0x141/0x4f0 block/fops.c:677
       do_dentry_open+0x674/0x1470 fs/open.c:1000
       vfs_open_consume+0xcc/0x460 fs/open.c:1131
       do_open fs/namei.c:4851 [inline]
       path_openat+0x1547/0x23f0 fs/namei.c:5016
       do_file_open+0x20e/0x430 fs/namei.c:5045
       do_sys_openat2+0x163/0x1d0 fs/open.c:1443
       do_sys_open fs/open.c:1449 [inline]
       __do_sys_openat fs/open.c:1465 [inline]
       __se_sys_openat fs/open.c:1460 [inline]
       __x64_sys_openat+0x12d/0x210 fs/open.c:1460
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x123/0x7b0 arch/x86/entry/syscall_64.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  (wq_completion)md_misc --> &mddev->reconfig_mutex --> major_names_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(major_names_lock);
                               lock(&mddev->reconfig_mutex);
                               lock(major_names_lock);
  lock((wq_completion)md_misc);

 *** DEADLOCK ***

locks held by syz.8.598/8400: 1, on CPU#2:
 #0: ffffffff90be60e0 (major_names_lock){+.+.}-{4:4}, at: blk_probe_dev+0x28/0x1e0 block/genhd.c:885

stack backtrace:
CPU: 2 UID: 0 PID: 8400 Comm: syz.8.598 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2087
 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2219
 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288
 lock_acquire kernel/locking/lockdep.c:5942 [inline]
 lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
 touch_wq_lockdep_map+0xad/0x1c0 kernel/workqueue.c:4272
 __flush_workqueue+0x131/0x1200 kernel/workqueue.c:4314
 md_alloc+0x30/0x10c0 drivers/md/md.c:6353
 md_alloc_and_put drivers/md/md.c:6452 [inline]
 md_probe drivers/md/md.c:6468 [inline]
 md_probe+0x73/0xf0 drivers/md/md.c:6463
 blk_probe_dev+0x149/0x1e0 block/genhd.c:888
 blk_request_module+0x16/0xc0 block/genhd.c:901
 blkdev_get_no_open+0x9b/0xf0 block/bdev.c:870
 blkdev_open+0x141/0x4f0 block/fops.c:677
 do_dentry_open+0x674/0x1470 fs/open.c:1000
 vfs_open_consume+0xcc/0x460 fs/open.c:1131
 do_open fs/namei.c:4851 [inline]
 path_openat+0x1547/0x23f0 fs/namei.c:5016
 do_file_open+0x20e/0x430 fs/namei.c:5045
 do_sys_openat2+0x163/0x1d0 fs/open.c:1443
 do_sys_open fs/open.c:1449 [inline]
 __do_sys_openat fs/open.c:1465 [inline]
 __se_sys_openat fs/open.c:1460 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1460
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x7b0 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc551b9fb19
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc55298e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc551e25fa0 RCX: 00007fc551b9fb19
RDX: 0000000000000002 RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007fc551c37b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc551e26038 R14: 00007fc551e25fa0 R15: 00007ffde87b81e8
 </TASK>
md: async del_gendisk mode will be removed in future, please upgrade to mdadm-4.5+
block device autoloading is deprecated and will be removed.