======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.328/4399 is trying to acquire lock:
ffff800088af38c0 (major_names_lock){+.+.}-{4:4}, at: blk_probe_dev+0x44/0x1a4 block/genhd.c:885

but task is already holding lock:
ffff000019a22358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_lock drivers/md/md.h:713 [inline]
ffff000019a22358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_suspend_and_lock drivers/md/md.h:1026 [inline]
ffff000019a22358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_suspend_and_lock drivers/md/md.h:1018 [inline]
ffff000019a22358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: md_ioctl+0xab8/0x2dd4 drivers/md/md.c:8426

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&mddev->reconfig_mutex){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x2b8/0x3fc kernel/locking/lockdep.c:5899
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x14c/0x1000 kernel/locking/mutex.c:821
       mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
       mddev_lock_nointr drivers/md/md.h:734 [inline]
       md_alloc+0x2d8/0xcb4 drivers/md/md.c:6413
       md_alloc_and_put drivers/md/md.c:6452 [inline]
       md_probe drivers/md/md.c:6468 [inline]
       md_probe+0x50/0x90 drivers/md/md.c:6463
       blk_probe_dev+0x110/0x1a4 block/genhd.c:888
       blk_request_module+0x18/0xa0 block/genhd.c:901
       blkdev_get_no_open+0x8c/0xec block/bdev.c:870
       blkdev_open+0xe4/0x3f4 block/fops.c:677
       do_dentry_open+0x35c/0xf24 fs/open.c:1000
       vfs_open_consume+0x8c/0x340 fs/open.c:1131
       do_open fs/namei.c:4851 [inline]
       path_openat+0xefc/0x1d50 fs/namei.c:5016
       do_file_open+0x18c/0x380 fs/namei.c:5045
       do_sys_openat2+0x134/0x184 fs/open.c:1443
       do_sys_open fs/open.c:1449 [inline]
       __do_compat_sys_openat fs/open.c:1511 [inline]
       __se_compat_sys_openat fs/open.c:1509 [inline]
       __arm64_compat_sys_openat+0x130/0x1d4 fs/open.c:1509
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x74/0x240 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:121
       do_el0_svc_compat+0x40/0x58 arch/arm64/kernel/syscall.c:146
       el0_svc_compat+0x54/0x1e0 arch/arm64/kernel/entry-common.c:948
       el0t_32_sync_handler+0x88/0xac arch/arm64/kernel/entry-common.c:966
       el0t_32_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:611

-> #1 (disks_mutex){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x2b8/0x3fc kernel/locking/lockdep.c:5899
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x14c/0x1000 kernel/locking/mutex.c:821
       mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
       md_alloc+0x4c/0xcb4 drivers/md/md.c:6355
       md_alloc_and_put drivers/md/md.c:6452 [inline]
       md_probe drivers/md/md.c:6468 [inline]
       md_probe+0x50/0x90 drivers/md/md.c:6463
       blk_probe_dev+0x110/0x1a4 block/genhd.c:888
       blk_request_module+0x18/0xa0 block/genhd.c:901
       blkdev_get_no_open+0x8c/0xec block/bdev.c:870
       blkdev_open+0xe4/0x3f4 block/fops.c:677
       do_dentry_open+0x35c/0xf24 fs/open.c:1000
       vfs_open_consume+0x8c/0x340 fs/open.c:1131
       do_open fs/namei.c:4851 [inline]
       path_openat+0xefc/0x1d50 fs/namei.c:5016
       do_file_open+0x18c/0x380 fs/namei.c:5045
       do_sys_openat2+0x134/0x184 fs/open.c:1443
       do_sys_open fs/open.c:1449 [inline]
       __do_compat_sys_openat fs/open.c:1511 [inline]
       __se_compat_sys_openat fs/open.c:1509 [inline]
       __arm64_compat_sys_openat+0x130/0x1d4 fs/open.c:1509
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x74/0x240 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:121
       do_el0_svc_compat+0x40/0x58 arch/arm64/kernel/syscall.c:146
       el0_svc_compat+0x54/0x1e0 arch/arm64/kernel/entry-common.c:948
       el0t_32_sync_handler+0x88/0xac arch/arm64/kernel/entry-common.c:966
       el0t_32_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:611

-> #0 (major_names_lock){+.+.}-{4:4}:
       check_prev_add+0x110/0xcb4 kernel/locking/lockdep.c:3209
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x1490/0x1af0 kernel/locking/lockdep.c:5288
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x2b8/0x3fc kernel/locking/lockdep.c:5899
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x14c/0x1000 kernel/locking/mutex.c:821
       mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
       blk_probe_dev+0x44/0x1a4 block/genhd.c:885
       blk_request_module+0x18/0xa0 block/genhd.c:901
       blkdev_get_no_open+0x8c/0xec block/bdev.c:870
       bdev_file_open_by_dev block/bdev.c:1091 [inline]
       bdev_file_open_by_dev+0x60/0x160 block/bdev.c:1079
       md_import_device+0xe4/0x370 drivers/md/md.c:3861
       md_add_new_disk+0x38c/0x146c drivers/md/md.c:7536
       md_ioctl+0x1e88/0x2dd4 drivers/md/md.c:8525
       md_compat_ioctl+0x2c/0xe0 drivers/md/md.c:8586
       compat_blkdev_ioctl+0x5c4/0x810 block/ioctl.c:854
       __do_compat_sys_ioctl fs/ioctl.c:695 [inline]
       __se_compat_sys_ioctl fs/ioctl.c:638 [inline]
       __arm64_compat_sys_ioctl+0x1a8/0x218 fs/ioctl.c:638
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x74/0x240 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:121
       do_el0_svc_compat+0x40/0x58 arch/arm64/kernel/syscall.c:146
       el0_svc_compat+0x54/0x1e0 arch/arm64/kernel/entry-common.c:948
       el0t_32_sync_handler+0x88/0xac arch/arm64/kernel/entry-common.c:966
       el0t_32_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:611

other info that might help us debug this:

Chain exists of:
  major_names_lock --> disks_mutex --> &mddev->reconfig_mutex

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

locks held by syz.0.328/4399: 1, last CPU#0:
 #0: ffff000019a22358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_lock drivers/md/md.h:713 [inline]
 #0: ffff000019a22358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_suspend_and_lock drivers/md/md.h:1026 [inline]
 #0: ffff000019a22358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_suspend_and_lock drivers/md/md.h:1018 [inline]
 #0: ffff000019a22358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: md_ioctl+0xab8/0x2dd4 drivers/md/md.c:8426

stack backtrace:
CPU: 0 UID: 0 PID: 4399 Comm: syz.0.328 Not tainted syzkaller #0 PREEMPT 
Hardware name: linux,dummy-virt (DT)
Call trace:
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x7c/0xb0 lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_circular_bug+0x23c/0x284 kernel/locking/lockdep.c:2087
 check_noncircular+0x174/0x194 kernel/locking/lockdep.c:2219
 check_prev_add+0x110/0xcb4 kernel/locking/lockdep.c:3209
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x1490/0x1af0 kernel/locking/lockdep.c:5288
 lock_acquire kernel/locking/lockdep.c:5942 [inline]
 lock_acquire+0x2b8/0x3fc kernel/locking/lockdep.c:5899
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x14c/0x1000 kernel/locking/mutex.c:821
 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
 blk_probe_dev+0x44/0x1a4 block/genhd.c:885
 blk_request_module+0x18/0xa0 block/genhd.c:901
 blkdev_get_no_open+0x8c/0xec block/bdev.c:870
 bdev_file_open_by_dev block/bdev.c:1091 [inline]
 bdev_file_open_by_dev+0x60/0x160 block/bdev.c:1079
 md_import_device+0xe4/0x370 drivers/md/md.c:3861
 md_add_new_disk+0x38c/0x146c drivers/md/md.c:7536
 md_ioctl+0x1e88/0x2dd4 drivers/md/md.c:8525
 md_compat_ioctl+0x2c/0xe0 drivers/md/md.c:8586
 compat_blkdev_ioctl+0x5c4/0x810 block/ioctl.c:854
 __do_compat_sys_ioctl fs/ioctl.c:695 [inline]
 __se_compat_sys_ioctl fs/ioctl.c:638 [inline]
 __arm64_compat_sys_ioctl+0x1a8/0x218 fs/ioctl.c:638
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x74/0x240 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:121
 do_el0_svc_compat+0x40/0x58 arch/arm64/kernel/syscall.c:146
 el0_svc_compat+0x54/0x1e0 arch/arm64/kernel/entry-common.c:948
 el0t_32_sync_handler+0x88/0xac arch/arm64/kernel/entry-common.c:966
 el0t_32_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:611
md: could not open device unknown-block(0,0).
md: md_import_device returned -6