======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.9.1923/14920 is trying to acquire lock:
ffffffff8e191a48 (major_names_lock){+.+.}-{3:3}, at: blk_probe_dev block/genhd.c:753 [inline]
ffffffff8e191a48 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x31/0x290 block/genhd.c:769

but task is already holding lock:
ffff8880742902d0
 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: mddev_lock drivers/md/md.h:577 [inline]
 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: new_dev_store+0x222/0x660 drivers/md/md.c:4641

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&mddev->reconfig_mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xb40 kernel/locking/mutex.c:747
       mddev_lock drivers/md/md.h:577 [inline]
       array_state_store+0x2e4/0x9c0 drivers/md/md.c:4480
       md_attr_store+0x183/0x220 drivers/md/md.c:5634
       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 (kn->active#73){++++}-{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

-> #2 ((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

-> #1 ((wq_completion)md_misc){+.+.}-{0:0}:
       __flush_workqueue+0x165/0x1380 kernel/workqueue.c:2816
       md_alloc+0x2e/0xd00 drivers/md/md.c:5709
       md_alloc_and_put drivers/md/md.c:5801 [inline]
       md_probe+0x53/0xc0 drivers/md/md.c:5814
       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:3838
       do_filp_open+0x1ee/0x420 fs/namei.c:3865
       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

-> #0 (major_names_lock){+.+.}-{3:3}:
       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
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xb40 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:2562 [inline]
       md_import_device+0x379/0x800 drivers/md/md.c:3752
       new_dev_store+0x38d/0x660 drivers/md/md.c:-1
       md_attr_store+0x183/0x220 drivers/md/md.c:5634
       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

other info that might help us debug this:

Chain exists of:
  major_names_lock --> kn->active#73 --> &mddev->reconfig_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mddev->reconfig_mutex);
                               lock(kn->active#73);
                               lock(&mddev->reconfig_mutex);
  lock(major_names_lock);

 *** DEADLOCK ***

5 locks held by syz.9.1923/14920:
 #0: ffff88804c7da0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
 #1: ffff88807dd02460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #2: ffff88807d2d8488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
 #3: ffff88806352d490 (kn->active#77){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #3: ffff88806352d490 (kn->active#77){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x520 fs/kernfs/file.c:344
 #4: ffff8880742902d0 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: mddev_lock drivers/md/md.h:577 [inline]
 #4: ffff8880742902d0 (&mddev->reconfig_mutex){+.+.}-{3:3}, at: new_dev_store+0x222/0x660 drivers/md/md.c:4641

stack backtrace:
CPU: 0 PID: 14920 Comm: syz.9.1923 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
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x12d/0xb40 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:2562 [inline]
 md_import_device+0x379/0x800 drivers/md/md.c:3752
 new_dev_store+0x38d/0x660 drivers/md/md.c:-1
 md_attr_store+0x183/0x220 drivers/md/md.c:5634
 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
RIP: 0033:0x7fe30579fb19
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:00007fe306699028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe305a25fa0 RCX: 00007fe30579fb19
RDX: 0000000000000016 RSI: 0000200000000280 RDI: 0000000000000007
RBP: 00007fe305837af8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe305a26038 R14: 00007fe305a25fa0 R15: 00007ffdb4c2fd28
 </TASK>
debugfs: creating file 'ram18'
device: 'ram18': device_add
kobject: 'ram18' (ffff888140c76e48): kobject_add_internal: parent: 'block', set: 'devices'
block ram18: No ACPI support
PM: Adding info for No Bus:ram18
kobject: 'ram18' (ffff888140c76e48): kobject_uevent_env
kobject: 'ram18' (ffff888140c76e48): kobject_uevent_env: uevent_suppress caused the event to drop!
kobject: 'holders' (ffff888067240200): kobject_add_internal: parent: 'ram18', set: '<NULL>'
kobject: 'slaves' (ffff888067240b80): kobject_add_internal: parent: 'ram18', set: '<NULL>'
kobject: 'queue' (ffff8880282b5d00): kobject_add_internal: parent: 'ram18', set: '<NULL>'
debugfs: creating file 'ram18'
kobject: 'queue' (ffff8880282b5d00): kobject_uevent_env
kobject: 'queue' (ffff8880282b5d00): kobject_uevent_env: filter function caused the event to drop!
device: '1:18': device_add
kobject: '1:18' (ffff888073592000): kobject_add_internal: parent: 'bdi', set: 'devices'
bdi 1:18: No ACPI support
PM: Adding info for No Bus:1:18
kobject: '1:18' (ffff888073592000): kobject_uevent_env
kobject: '1:18' (ffff888073592000): fill_kobj_path: path = '/devices/virtual/bdi/1:18'
debugfs: creating file '1:18'
debugfs: creating file 'stats'
kobject: 'ram18' (ffff888140c76e48): kobject_uevent_env
kobject: 'ram18' (ffff888140c76e48): fill_kobj_path: path = '/devices/virtual/block/ram18'
block device autoloading is deprecated and will be removed.
md: bind<ram18>
kobject: 'dev-ram18' (ffff888079536878): kobject_add_internal: parent: 'md', set: '<NULL>'
kcov: kcov_task_exit: t = ffff88802f645a00, kcov->t = ffff88802f645a00