loop3: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected 5.15.0-rc2-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/22450 is trying to acquire lock: ffff888072d90230 (&mddev->open_mutex){+.+.}-{3:3}, at: md_open+0x227/0x320 drivers/md/md.c:7815 but task is already holding lock: ffff88807e3f6918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0xf6/0xb90 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}: lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5625 __mutex_lock_common+0x1df/0x2550 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:743 bd_register_pending_holders+0x32/0x370 block/holder.c:160 device_add_disk+0x4df/0xe70 block/genhd.c:475 add_disk include/linux/genhd.h:221 [inline] md_alloc+0x829/0xc70 drivers/md/md.c:5707 blk_request_module+0x19d/0x1c0 block/genhd.c:637 blkdev_get_no_open+0x37/0x180 block/bdev.c:739 blkdev_get_by_dev+0x84/0xb90 block/bdev.c:803 ext4_blkdev_get fs/ext4/super.c:1079 [inline] ext4_get_dev_journal fs/ext4/super.c:5185 [inline] ext4_load_journal fs/ext4/super.c:5296 [inline] ext4_fill_super+0x9d37/0xf160 fs/ext4/super.c:4644 mount_bdev+0x26c/0x3a0 fs/super.c:1368 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x86/0x270 fs/super.c:1498 do_new_mount fs/namespace.c:2988 [inline] path_mount+0x1986/0x2c30 fs/namespace.c:3318 do_mount fs/namespace.c:3331 [inline] __do_sys_mount fs/namespace.c:3539 [inline] __se_sys_mount+0x308/0x3c0 fs/namespace.c:3516 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 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+0x1dfb/0x8240 kernel/locking/lockdep.c:3789 __lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5015 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5625 __mutex_lock_common+0x1df/0x2550 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_interruptible_nested+0x1a/0x20 kernel/locking/mutex.c:765 md_open+0x227/0x320 drivers/md/md.c:7815 blkdev_get_whole+0x95/0x3e0 block/bdev.c:668 blkdev_get_by_dev+0x28d/0xb90 block/bdev.c:823 ext4_blkdev_get fs/ext4/super.c:1079 [inline] ext4_get_dev_journal fs/ext4/super.c:5185 [inline] ext4_load_journal fs/ext4/super.c:5296 [inline] ext4_fill_super+0x9d37/0xf160 fs/ext4/super.c:4644 mount_bdev+0x26c/0x3a0 fs/super.c:1368 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x86/0x270 fs/super.c:1498 do_new_mount fs/namespace.c:2988 [inline] path_mount+0x1986/0x2c30 fs/namespace.c:3318 do_mount fs/namespace.c:3331 [inline] __do_sys_mount fs/namespace.c:3539 [inline] __se_sys_mount+0x308/0x3c0 fs/namespace.c:3516 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 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 *** 2 locks held by syz-executor.3/22450: #0: ffff8880268640e0 (&type->s_umount_key#26/1){+.+.}-{3:3}, at: alloc_super+0x1c8/0x860 fs/super.c:229 #1: ffff88807e3f6918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0xf6/0xb90 block/bdev.c:816 stack backtrace: CPU: 1 PID: 22450 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+0x1dc/0x2d8 lib/dump_stack.c:106 check_noncircular+0x2f9/0x3b0 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+0x1dfb/0x8240 kernel/locking/lockdep.c:3789 __lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5015 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5625 __mutex_lock_common+0x1df/0x2550 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_interruptible_nested+0x1a/0x20 kernel/locking/mutex.c:765 md_open+0x227/0x320 drivers/md/md.c:7815 blkdev_get_whole+0x95/0x3e0 block/bdev.c:668 blkdev_get_by_dev+0x28d/0xb90 block/bdev.c:823 ext4_blkdev_get fs/ext4/super.c:1079 [inline] ext4_get_dev_journal fs/ext4/super.c:5185 [inline] ext4_load_journal fs/ext4/super.c:5296 [inline] ext4_fill_super+0x9d37/0xf160 fs/ext4/super.c:4644 mount_bdev+0x26c/0x3a0 fs/super.c:1368 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x86/0x270 fs/super.c:1498 do_new_mount fs/namespace.c:2988 [inline] path_mount+0x1986/0x2c30 fs/namespace.c:3318 do_mount fs/namespace.c:3331 [inline] __do_sys_mount fs/namespace.c:3539 [inline] __se_sys_mount+0x308/0x3c0 fs/namespace.c:3516 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fab53960c2a Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 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:00007fab50ed5fa8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007fab53960c2a RDX: 0000000020000000 RSI: 0000000020001d40 RDI: 00007fab50ed6000 RBP: 00007fab50ed6040 R08: 00007fab50ed6040 R09: 0000000020000000 R10: 0000000000400001 R11: 0000000000000206 R12: 0000000020000000 R13: 0000000020001d40 R14: 00007fab50ed6000 R15: 0000000020000140 EXT4-fs (loop3): couldn't read superblock of external journal