======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.8.15029/6869 is trying to acquire lock:
ffffffff90555240 (major_names_lock){+.+.}-{4:4}, at: blk_request_module+0x35/0x2a0

but task is already holding lock:
ffff88816e018358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: new_dev_store+0x29c/0x860

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&mddev->reconfig_mutex){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1550
       md_start_sync+0x15a/0x1010
       process_scheduled_works+0xc3d/0x1630
       worker_thread+0xa47/0xfb0
       kthread+0x38b/0x480
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #2 ((work_completion)(&mddev->sync_work)){+.+.}-{0:0}:
       process_scheduled_works+0xc03/0x1630
       worker_thread+0xa47/0xfb0
       kthread+0x38b/0x480
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #1 ((wq_completion)md_misc){+.+.}-{0:0}:
       touch_wq_lockdep_map+0xcb/0x180
       __flush_workqueue+0x148/0x1470
       md_alloc+0x32/0xf20
       md_alloc_and_put+0x1a/0x1f0
       blk_request_module+0x27d/0x2a0
       blkdev_get_no_open+0x3f/0xe0
       bdev_file_open_by_dev+0xa0/0x240
       swsusp_check+0x56/0x490
       software_resume+0x51/0x4c0
       resume_store+0x333/0x4f0
       kernfs_fop_write_iter+0x3a4/0x540
       vfs_write+0x612/0xba0
       ksys_write+0x150/0x270
       do_syscall_64+0x166/0x520
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (major_names_lock){+.+.}-{4:4}:
       __lock_acquire+0x164c/0x2de0
       lock_acquire+0x115/0x350
       __mutex_lock+0x19d/0x1550
       blk_request_module+0x35/0x2a0
       blkdev_get_no_open+0x3f/0xe0
       bdev_file_open_by_dev+0xa0/0x240
       md_import_device+0x2e9/0x650
       new_dev_store+0x46d/0x860
       md_attr_store+0x3b7/0x640
       kernfs_fop_write_iter+0x3a4/0x540
       vfs_write+0x612/0xba0
       ksys_write+0x150/0x270
       do_syscall_64+0x166/0x520
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  major_names_lock --> (work_completion)(&mddev->sync_work) --> &mddev->reconfig_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mddev->reconfig_mutex);
                               lock((work_completion)(&mddev->sync_work));
                               lock(&mddev->reconfig_mutex);
  lock(major_names_lock);

 *** DEADLOCK ***

locks held by syz.8.15029/6869: 5, last CPU#0:
 #0: ffff888111cc58f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff88810e204460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffff88811176ec80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540
 #3: ffff888117f0af08 (kn->active#60){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540
 #4: ffff88816e018358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: new_dev_store+0x29c/0x860

stack backtrace:
CPU: 0 UID: 0 PID: 6869 Comm: syz.8.15029 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_circular_bug+0x2e2/0x300
 check_noncircular+0x12f/0x150
 __lock_acquire+0x164c/0x2de0
 lock_acquire+0x115/0x350
 __mutex_lock+0x19d/0x1550
 blk_request_module+0x35/0x2a0
 blkdev_get_no_open+0x3f/0xe0
 bdev_file_open_by_dev+0xa0/0x240
 md_import_device+0x2e9/0x650
 new_dev_store+0x46d/0x860
 md_attr_store+0x3b7/0x640
 kernfs_fop_write_iter+0x3a4/0x540
 vfs_write+0x612/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdd53b9f559
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:00007fdd54af5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdd53e25fa0 RCX: 00007fdd53b9f559
RDX: 0000000000000016 RSI: 0000200000000280 RDI: 0000000000000007
RBP: 00007fdd53c36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdd53e26038 R14: 00007fdd53e25fa0 R15: 00007ffff3bdb498
 </TASK>
block device autoloading is deprecated and will be removed.
md: pers->run() failed ...
md: md8 stopped.
