====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.9.4989/25126 is trying to acquire lock: ffffffff8fbb4518 (major_names_lock){+.+.}-{4:4}, at: blk_probe_dev block/genhd.c:885 [inline] ffffffff8fbb4518 (major_names_lock){+.+.}-{4:4}, at: blk_request_module+0x35/0x2a0 block/genhd.c:901 but task is already holding lock: ffff888035d24340 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_lock drivers/md/md.h:713 [inline] ffff888035d24340 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_suspend_and_lock+0x48/0xf0 drivers/md/md.h:1026 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&mddev->reconfig_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline] mutex_lock_nested+0x55/0x1d0 kernel/locking/rtmutex_api.c:580 mddev_lock_nointr drivers/md/md.h:734 [inline] md_alloc+0x81e/0xf40 drivers/md/md.c:6413 md_alloc_and_put+0x1a/0x1f0 drivers/md/md.c:6452 blk_probe_dev block/genhd.c:888 [inline] blk_request_module+0x27d/0x2a0 block/genhd.c:-1 blkdev_get_no_open+0x3f/0xe0 block/bdev.c:870 blkdev_open+0x1e9/0x630 block/fops.c:673 do_dentry_open+0x841/0x1410 fs/open.c:1000 vfs_open_consume+0x4a/0x360 fs/open.c:1131 do_open fs/namei.c:4851 [inline] path_openat+0x1701/0x2100 fs/namei.c:5016 do_file_open+0x23e/0x4a0 fs/namei.c:5045 do_sys_openat2+0x115/0x200 fs/open.c:1443 do_sys_open fs/open.c:1449 [inline] __do_sys_openat fs/open.c:1465 [inline] __se_sys_openat fs/open.c:1460 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1460 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (disks_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline] mutex_lock_nested+0x55/0x1d0 kernel/locking/rtmutex_api.c:580 md_alloc+0x40/0xf40 drivers/md/md.c:6355 md_alloc_and_put+0x1a/0x1f0 drivers/md/md.c:6452 blk_probe_dev block/genhd.c:888 [inline] blk_request_module+0x27d/0x2a0 block/genhd.c:-1 blkdev_get_no_open+0x3f/0xe0 block/bdev.c:870 blkdev_open+0x1e9/0x630 block/fops.c:673 do_dentry_open+0x841/0x1410 fs/open.c:1000 vfs_open_consume+0x4a/0x360 fs/open.c:1131 do_open fs/namei.c:4851 [inline] path_openat+0x1701/0x2100 fs/namei.c:5016 do_file_open+0x23e/0x4a0 fs/namei.c:5045 do_sys_openat2+0x115/0x200 fs/open.c:1443 do_sys_open fs/open.c:1449 [inline] __do_sys_openat fs/open.c:1465 [inline] __se_sys_openat fs/open.c:1460 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1460 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #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+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline] mutex_lock_nested+0x55/0x1d0 kernel/locking/rtmutex_api.c:580 blk_probe_dev block/genhd.c:885 [inline] blk_request_module+0x35/0x2a0 block/genhd.c:901 blkdev_get_no_open+0x3f/0xe0 block/bdev.c:870 bdev_file_open_by_dev+0xa0/0x240 block/bdev.c:1091 md_import_device+0x2e9/0x650 drivers/md/md.c:3861 md_add_new_disk+0x3a3/0x1850 drivers/md/md.c:7536 md_ioctl+0x2027/0x2630 drivers/md/md.c:8525 blkdev_ioctl+0x5e6/0x750 block/ioctl.c:798 vfs_ioctl fs/ioctl.c:52 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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.9.4989/25126: 1, on CPU#1: #0: ffff888035d24340 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_lock drivers/md/md.h:713 [inline] #0: ffff888035d24340 (&mddev->reconfig_mutex){+.+.}-{4:4}, at: mddev_suspend_and_lock+0x48/0xf0 drivers/md/md.h:1026 stack backtrace: CPU: 1 UID: 0 PID: 25126 Comm: syz.9.4989 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087 check_noncircular+0x12f/0x150 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+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline] mutex_lock_nested+0x55/0x1d0 kernel/locking/rtmutex_api.c:580 blk_probe_dev block/genhd.c:885 [inline] blk_request_module+0x35/0x2a0 block/genhd.c:901 blkdev_get_no_open+0x3f/0xe0 block/bdev.c:870 bdev_file_open_by_dev+0xa0/0x240 block/bdev.c:1091 md_import_device+0x2e9/0x650 drivers/md/md.c:3861 md_add_new_disk+0x3a3/0x1850 drivers/md/md.c:7536 md_ioctl+0x2027/0x2630 drivers/md/md.c:8525 blkdev_ioctl+0x5e6/0x750 block/ioctl.c:798 vfs_ioctl fs/ioctl.c:52 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f754a428f19 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:00007f7548655028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f754a6a6090 RCX: 00007f754a428f19 RDX: 00002000000001c0 RSI: 0000000040140921 RDI: 0000000000000004 RBP: 00007f754a4b7f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f754a6a6128 R14: 00007f754a6a6090 R15: 00007ffdf5d8c0e8 block device autoloading is deprecated and will be removed. md: invalid raid superblock magic on ram18 md: ram18 does not have a valid v0.0 superblock, not importing! md: md_import_device returned -22