======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1331/9775 is trying to acquire lock:
ffff80008911bc40 (major_names_lock){+.+.}-{4:4}, at: blk_probe_dev+0x3c/0x158 block/genhd.c:885

but task is already holding lock:
ffff0000d72e8358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_lock drivers/md/md.h:713 [inline]
ffff0000d72e8358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_suspend_and_lock+0x4c/0xd8 drivers/md/md.h:1019

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&mddev->reconfig_mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x164/0xf14 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_start_sync+0xdc/0xc80 drivers/md/md.c:10275
       process_one_work kernel/workqueue.c:3396 [inline]
       process_scheduled_works+0x91c/0x1250 kernel/workqueue.c:3479
       worker_thread+0x798/0xbd0 kernel/workqueue.c:3560
       kthread+0x304/0x3d4 kernel/kthread.c:436
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:838

-> #2 ((work_completion)(&mddev->sync_work)){+.+.}-{0:0}:
       process_one_work kernel/workqueue.c:3372 [inline]
       process_scheduled_works+0x8f0/0x1250 kernel/workqueue.c:3479
       worker_thread+0x798/0xbd0 kernel/workqueue.c:3560
       kthread+0x304/0x3d4 kernel/kthread.c:436
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:838

-> #1 ((wq_completion)md_misc){+.+.}-{0:0}:
       touch_wq_lockdep_map+0xb4/0x15c kernel/workqueue.c:4111
       __flush_workqueue+0x114/0xd74 kernel/workqueue.c:4153
       md_alloc+0x44/0x9fc drivers/md/md.c:6334
       md_alloc_and_put+0x28/0x84 drivers/md/md.c:6423
       md_probe+0x6c/0x88 drivers/md/md.c:6439
       blk_probe_dev+0x12c/0x158 block/genhd.c:888
       blk_request_module+0x24/0xc0 block/genhd.c:901
       blkdev_get_no_open+0x4c/0xf8 block/bdev.c:870
       blkdev_open+0xfc/0x408 block/fops.c:665
       do_dentry_open+0x5c4/0xfc0 fs/open.c:996
       vfs_open+0x44/0x2dc fs/open.c:1101
       do_open fs/namei.c:4837 [inline]
       path_openat+0x1084/0x18f4 fs/namei.c:5000
       do_file_open+0x1c8/0x2e8 fs/namei.c:5029
       do_sys_openat2+0x114/0x1e8 fs/open.c:1417
       do_sys_open+0xb0/0xe0 fs/open.c:1423
       __do_sys_openat fs/open.c:1439 [inline]
       __se_sys_openat fs/open.c:1434 [inline]
       __arm64_sys_openat+0xa8/0xc4 fs/open.c:1434
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
       do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
       el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758
       el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590

-> #0 (major_names_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3209 [inline]
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x1660/0x2b48 kernel/locking/lockdep.c:5288
       lock_acquire+0x150/0x370 kernel/locking/lockdep.c:5942
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x164/0xf14 kernel/locking/mutex.c:821
       mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
       blk_probe_dev+0x3c/0x158 block/genhd.c:885
       blk_request_module+0x24/0xc0 block/genhd.c:901
       blkdev_get_no_open+0x4c/0xf8 block/bdev.c:870
       bdev_file_open_by_dev+0x80/0x1d8 block/bdev.c:1091
       md_import_device+0xfc/0x354 drivers/md/md.c:3847
       md_add_new_disk+0x42c/0x144c drivers/md/md.c:7549
       md_ioctl+0x1d68/0x23d4 drivers/md/md.c:8499
       blkdev_ioctl+0x574/0x904 block/ioctl.c:798
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:597 [inline]
       __se_sys_ioctl fs/ioctl.c:583 [inline]
       __arm64_sys_ioctl+0x154/0x1cc fs/ioctl.c:583
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
       do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
       el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758
       el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590

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.0.1331/9775: 1, last CPU#0:
 #0: ffff0000d72e8358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_lock drivers/md/md.h:713 [inline]
 #0: ffff0000d72e8358 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_suspend_and_lock+0x4c/0xd8 drivers/md/md.h:1019

stack backtrace:
CPU: 0 UID: 0 PID: 9775 Comm: syz.0.1331 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_circular_bug+0x328/0x330 kernel/locking/lockdep.c:2087
 check_noncircular+0x158/0x174 kernel/locking/lockdep.c:2219
 check_prev_add kernel/locking/lockdep.c:3209 [inline]
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x1660/0x2b48 kernel/locking/lockdep.c:5288
 lock_acquire+0x150/0x370 kernel/locking/lockdep.c:5942
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x164/0xf14 kernel/locking/mutex.c:821
 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
 blk_probe_dev+0x3c/0x158 block/genhd.c:885
 blk_request_module+0x24/0xc0 block/genhd.c:901
 blkdev_get_no_open+0x4c/0xf8 block/bdev.c:870
 bdev_file_open_by_dev+0x80/0x1d8 block/bdev.c:1091
 md_import_device+0xfc/0x354 drivers/md/md.c:3847
 md_add_new_disk+0x42c/0x144c drivers/md/md.c:7549
 md_ioctl+0x1d68/0x23d4 drivers/md/md.c:8499
 blkdev_ioctl+0x574/0x904 block/ioctl.c:798
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __arm64_sys_ioctl+0x154/0x1cc fs/ioctl.c:583
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758
 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590
md: could not open device unknown-block(0,0).
md: md_import_device returned -6