====================================================== WARNING: possible circular locking dependency detected 5.15.0-rc2-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/13287 is trying to acquire lock: ffff888098cb0230 (&mddev->open_mutex){+.+.}-{3:3}, at: md_open+0xfd/0x2e0 drivers/md/md.c:7815 but task is already holding lock: ffff88807b6fc918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb60 block/bdev.c:816 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:596 [inline] __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729 bd_register_pending_holders+0x2c/0x470 block/holder.c:160 device_add_disk+0x74c/0xfc0 block/genhd.c:475 add_disk include/linux/genhd.h:221 [inline] md_alloc+0x91d/0x1150 drivers/md/md.c:5707 md_probe+0x69/0x70 drivers/md/md.c:5738 blk_request_module+0x111/0x1d0 block/genhd.c:637 blkdev_get_no_open+0x178/0x1e0 block/bdev.c:739 blkdev_get_by_dev.part.0+0x22/0xb60 block/bdev.c:803 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:856 blkdev_open+0x154/0x2b0 block/fops.c:447 do_dentry_open+0x4c8/0x11d0 fs/open.c:822 do_open fs/namei.c:3428 [inline] path_openat+0x1c9a/0x2740 fs/namei.c:3561 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_openat fs/open.c:1232 [inline] __se_sys_openat fs/open.c:1227 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1227 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&mddev->open_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __mutex_lock_common kernel/locking/mutex.c:596 [inline] __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729 md_open+0xfd/0x2e0 drivers/md/md.c:7815 blkdev_get_whole+0x99/0x2a0 block/bdev.c:668 blkdev_get_by_dev.part.0+0x354/0xb60 block/bdev.c:823 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:856 blkdev_open+0x154/0x2b0 block/fops.c:447 do_dentry_open+0x4c8/0x11d0 fs/open.c:822 do_open fs/namei.c:3428 [inline] path_openat+0x1c9a/0x2740 fs/namei.c:3561 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_openat fs/open.c:1232 [inline] __se_sys_openat fs/open.c:1227 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1227 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&disk->open_mutex); lock(&mddev->open_mutex); lock(&disk->open_mutex); lock(&mddev->open_mutex); *** DEADLOCK *** 1 lock held by syz-executor.3/13287: #0: ffff88807b6fc918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb60 block/bdev.c:816 stack backtrace: CPU: 1 PID: 13287 Comm: syz-executor.3 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __mutex_lock_common kernel/locking/mutex.c:596 [inline] __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729 md_open+0xfd/0x2e0 drivers/md/md.c:7815 blkdev_get_whole+0x99/0x2a0 block/bdev.c:668 blkdev_get_by_dev.part.0+0x354/0xb60 block/bdev.c:823 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:856 blkdev_open+0x154/0x2b0 block/fops.c:447 do_dentry_open+0x4c8/0x11d0 fs/open.c:822 do_open fs/namei.c:3428 [inline] path_openat+0x1c9a/0x2740 fs/namei.c:3561 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_openat fs/open.c:1232 [inline] __se_sys_openat fs/open.c:1227 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1227 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f34d9d59709 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f34d72af188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f34d9e5e020 RCX: 00007f34d9d59709 RDX: 0000000000000000 RSI: 00000000200020c0 RDI: ffffffffffffff9c RBP: 00007f34d9db3cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe3e33e9ef R14: 00007f34d72af300 R15: 0000000000022000