======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.7.1746/12920 is trying to acquire lock:
ffff888144e82938 ((wq_completion)md_misc){+.+.}-{0:0}, at: __flush_workqueue+0x14c/0x1380 kernel/workqueue.c:2812

but task is already holding lock:
ffffffff8e19d748 (major_names_lock){+.+.}-{3:3}
, at: blk_probe_dev block/genhd.c:753 [inline]
, at: blk_request_module+0x31/0x290 block/genhd.c:769

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (major_names_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
       blk_probe_dev block/genhd.c:753 [inline]
       blk_request_module+0x31/0x290 block/genhd.c:769
       blkdev_get_no_open+0x33/0xc0 block/bdev.c:758
       blkdev_get_by_dev+0x77/0xa60 block/bdev.c:815
       lock_rdev drivers/md/md.c:2561 [inline]
       md_import_device+0x379/0x800 drivers/md/md.c:3751
       new_dev_store+0x38d/0x660 drivers/md/md.c:-1
       md_attr_store+0x183/0x220 drivers/md/md.c:5633
       kernfs_fop_write_iter+0x3a0/0x520 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+0x482/0x9a0 fs/read_write.c:584
       ksys_write+0x14d/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #3 (&mddev->reconfig_mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
       mddev_lock drivers/md/md.h:577 [inline]
       array_state_store+0x2e4/0x9c0 drivers/md/md.c:4479
       md_attr_store+0x183/0x220 drivers/md/md.c:5633
       kernfs_fop_write_iter+0x3a0/0x520 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+0x482/0x9a0 fs/read_write.c:584
       ksys_write+0x14d/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (kn->active#79){++++}-{0:0}:
       kernfs_drain+0x31a/0x6d0 fs/kernfs/dir.c:499
       __kernfs_remove+0x3f4/0x6c0 fs/kernfs/dir.c:1461
       kernfs_remove_by_name_ns+0xd8/0x150 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+0xfd/0x290 fs/sysfs/group.c:288
       sysfs_remove_groups+0x50/0xa0 fs/sysfs/group.c:312
       __kobject_del+0x83/0x2e0 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+0x22f/0x450 lib/kobject.c:729
       process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
       worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
       kthread+0x29d/0x330 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #1 ((work_completion)(&mddev->del_work)){+.+.}-{0:0}
:
       process_one_work+0x7ec/0x1160 kernel/workqueue.c:2268
       worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
       kthread+0x29d/0x330 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #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+0x3a03/0x7ea0 kernel/locking/lockdep.c:5171
       lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
       __flush_workqueue+0x165/0x1380 kernel/workqueue.c:2812
       md_alloc+0x2e/0xd00 drivers/md/md.c:5708
       md_alloc_and_put drivers/md/md.c:5800 [inline]
       md_probe+0x53/0xc0 drivers/md/md.c:5813
       blk_probe_dev block/genhd.c:756 [inline]
       blk_request_module+0x26e/0x290 block/genhd.c:-1
       blkdev_get_no_open+0x33/0xc0 block/bdev.c:758
       blkdev_get_by_dev+0x77/0xa60 block/bdev.c:815
       blkdev_open+0x119/0x2d0 block/fops.c:500
       do_dentry_open+0x7dd/0x10b0 fs/open.c:882
       do_open fs/namei.c:3677 [inline]
       path_openat+0x2674/0x2f10 fs/namei.c:3834
       do_filp_open+0x1ee/0x420 fs/namei.c:3861
       do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
       do_sys_open fs/open.c:1336 [inline]
       __do_sys_openat fs/open.c:1352 [inline]
       __se_sys_openat fs/open.c:1347 [inline]
       __x64_sys_openat+0x135/0x160 fs/open.c:1347
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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 ***

1 lock held by syz.7.1746/12920:
 #0: ffffffff8e19d748 (major_names_lock){+.+.}-{3:3}, at: blk_probe_dev block/genhd.c:753 [inline]
 #0: ffffffff8e19d748 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x31/0x290 block/genhd.c:769

stack backtrace:
CPU: 1 PID: 12920 Comm: syz.7.1746 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x2f8/0x400 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+0x3a03/0x7ea0 kernel/locking/lockdep.c:5171
 lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
 __flush_workqueue+0x165/0x1380 kernel/workqueue.c:2812
 md_alloc+0x2e/0xd00 drivers/md/md.c:5708
 md_alloc_and_put drivers/md/md.c:5800 [inline]
 md_probe+0x53/0xc0 drivers/md/md.c:5813
 blk_probe_dev block/genhd.c:756 [inline]
 blk_request_module+0x26e/0x290 block/genhd.c:-1
 blkdev_get_no_open+0x33/0xc0 block/bdev.c:758
 blkdev_get_by_dev+0x77/0xa60 block/bdev.c:815
 blkdev_open+0x119/0x2d0 block/fops.c:500
 do_dentry_open+0x7dd/0x10b0 fs/open.c:882
 do_open fs/namei.c:3677 [inline]
 path_openat+0x2674/0x2f10 fs/namei.c:3834
 do_filp_open+0x1ee/0x420 fs/namei.c:3861
 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4e5f19f559
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:00007f4e6012c028 EFLAGS: 00000246
 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4e5f425fa0 RCX: 00007f4e5f19f559
RDX: 0000000000000002 RSI: 0000200000000b80 RDI: ffffffffffffff9c
RBP: 00007f4e5f236b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4e5f426038 R14: 00007f4e5f425fa0 R15: 00007ffee9306418
 </TASK>
device: 'md7': device_add
kobject: 'md7' (ffff888140c54248): kobject_add_internal: parent: 'block', set: 'devices'
block md7: No ACPI support
PM: Adding info for No Bus:md7
kobject: 'md7' (ffff888140c54248): kobject_uevent_env
kobject: 'md7' (ffff888140c54248): kobject_uevent_env: uevent_suppress caused the event to drop!
kobject: 'holders' (ffff888059789380): kobject_add_internal: parent: 'md7', set: '<NULL>'
kobject: 'slaves' (ffff88807c15ca00): kobject_add_internal: parent: 'md7', set: '<NULL>'
kobject: 'queue' (ffff888027d42f80): kobject_add_internal: parent: 'md7', set: '<NULL>'
debugfs: creating file 'md7'
kobject: 'queue' (ffff888027d42f80): kobject_uevent_env
kobject: 'queue' (ffff888027d42f80): kobject_uevent_env: filter function caused the event to drop!
device: '9:7': device_add
kobject: '9:7' (ffff88801d290000): kobject_add_internal: parent: 'bdi', set: 'devices'
bdi 9:7: No ACPI support
PM: Adding info for No Bus:9:7
kobject: '9:7' (ffff88801d290000): kobject_uevent_env
kobject: '9:7' (ffff88801d290000): fill_kobj_path: path = '/devices/virtual/bdi/9:7'
debugfs: creating file '9:7'
debugfs: creating file 'stats'
kobject: 'md7' (ffff888140c54248): kobject_uevent_env
kobject: 'md7' (ffff888140c54248): fill_kobj_path: path = '/devices/virtual/block/md7'
kobject: 'md' (ffff888077304060): kobject_add_internal: parent: 'md7', set: '<NULL>'
kobject: 'md' (ffff888077304060): kobject_uevent_env
kobject: 'md' (ffff888077304060): kobject_uevent_env: filter function caused the event to drop!
block device autoloading is deprecated and will be removed.
kcov: kcov_task_exit: t = ffff888027d4da00, kcov->t = ffff888027d4da00