block device autoloading is deprecated and will be removed. EXT4-fs (loop1): external journal has bad superblock ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.553/7533 is trying to acquire lock: ffff888020e494c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xff/0x760 block/bdev.c:944 but task is already holding lock: ffff88802ec6a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: ext4_get_journal_blkdev fs/ext4/super.c:5902 [inline] ffff88802ec6a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: ext4_open_dev_journal fs/ext4/super.c:5974 [inline] ffff88802ec6a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: ext4_load_journal fs/ext4/super.c:6037 [inline] ffff88802ec6a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: ext4_load_and_init_journal+0x280/0x2100 fs/ext4/super.c:4923 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&type->s_umount_key#32){++++}-{3:3}: down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 __super_lock fs/super.c:58 [inline] super_lock+0x17f/0x3a0 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] super_lock_shared_active fs/super.c:1442 [inline] fs_bdev_sync+0xa4/0x170 fs/super.c:1477 blkdev_flushbuf block/ioctl.c:381 [inline] blkdev_common_ioctl+0x8a6/0x2570 block/ioctl.c:511 blkdev_ioctl+0x512/0x730 block/ioctl.c:633 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&bdev->bd_holder_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747 bdev_mark_dead+0x31/0x1a0 block/bdev.c:1028 disk_force_media_change+0x14e/0x1d0 block/disk-events.c:302 __loop_clr_fd+0x396/0x660 drivers/block/loop.c:1170 blkdev_put+0x5bd/0x760 block/bdev.c:-1 bdev_release+0x57/0x70 block/bdev.c:968 kill_f2fs_super+0x326/0x3d0 fs/f2fs/super.c:4883 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&disk->open_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747 blkdev_put+0xff/0x760 block/bdev.c:944 ext4_get_journal_blkdev fs/ext4/super.c:5961 [inline] ext4_open_dev_journal fs/ext4/super.c:5974 [inline] ext4_load_journal fs/ext4/super.c:6037 [inline] ext4_load_and_init_journal+0xcef/0x2100 fs/ext4/super.c:4923 __ext4_fill_super fs/ext4/super.c:5411 [inline] ext4_fill_super+0x430a/0x67b0 fs/ext4/super.c:5744 get_tree_bdev+0x3f3/0x520 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &disk->open_mutex --> &bdev->bd_holder_lock --> &type->s_umount_key#32 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&type->s_umount_key#32); lock(&bdev->bd_holder_lock); lock(&type->s_umount_key#32); lock(&disk->open_mutex); *** DEADLOCK *** 1 lock held by syz.1.553/7533: #0: ffff88802ec6a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: ext4_get_journal_blkdev fs/ext4/super.c:5902 [inline] #0: ffff88802ec6a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: ext4_open_dev_journal fs/ext4/super.c:5974 [inline] #0: ffff88802ec6a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: ext4_load_journal fs/ext4/super.c:6037 [inline] #0: ffff88802ec6a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: ext4_load_and_init_journal+0x280/0x2100 fs/ext4/super.c:4923 stack backtrace: CPU: 0 PID: 7533 Comm: syz.1.553 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747 blkdev_put+0xff/0x760 block/bdev.c:944 ext4_get_journal_blkdev fs/ext4/super.c:5961 [inline] ext4_open_dev_journal fs/ext4/super.c:5974 [inline] ext4_load_journal fs/ext4/super.c:6037 [inline] ext4_load_and_init_journal+0xcef/0x2100 fs/ext4/super.c:4923 __ext4_fill_super fs/ext4/super.c:5411 [inline] ext4_fill_super+0x430a/0x67b0 fs/ext4/super.c:5744 get_tree_bdev+0x3f3/0x520 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8baa59da8a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f8bab3d8e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f8bab3d8ee0 RCX: 00007f8baa59da8a RDX: 0000200000000180 RSI: 0000200000000480 RDI: 00007f8bab3d8ea0 RBP: 0000200000000180 R08: 00007f8bab3d8ee0 R09: 00000000c0ed4040 R10: 00000000c0ed4040 R11: 0000000000000246 R12: 0000200000000480 R13: 00007f8bab3d8ea0 R14: 000000000000047a R15: 00002000000004c0 netlink: 12 bytes leftover after parsing attributes in process `syz.1.553'. ipvlan2: entered allmulticast mode syz_tun: entered allmulticast mode