BTRFS info (device loop4): last unmount of filesystem a6a605fc-d5f1-4e66-8595-3726e2b761d6 BUG: MAX_LOCKDEP_KEYS too low! turning off the locking correctness validator. CPU: 0 UID: 0 PID: 5853 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 register_lock_class+0x2e8/0x320 kernel/locking/lockdep.c:1332 __lock_acquire+0x99/0xd20 kernel/locking/lockdep.c:5112 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 touch_wq_lockdep_map+0xcb/0x180 kernel/workqueue.c:3907 __flush_workqueue+0x121/0x14b0 kernel/workqueue.c:3949 close_ctree+0x30d/0x1380 fs/btrfs/disk-io.c:4265 generic_shutdown_super+0x132/0x2c0 fs/super.c:643 kill_anon_super+0x3b/0x70 fs/super.c:1282 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2131 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff93e4a01f7 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd6c5a0228 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ff93e521d7d RCX: 00007ff93e4a01f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd6c5a02e0 RBP: 00007ffd6c5a02e0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd6c5a1370 R13: 00007ff93e521d7d R14: 000000000011ad07 R15: 00007ffd6c5a13b0