BTRFS info (device loop5): last unmount of filesystem 395ef67a-297e-477c-816d-cd80a5b93e5d BUG: MAX_LOCKDEP_CHAINS too low! turning off the locking correctness validator. CPU: 0 PID: 4794 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 add_chain_cache kernel/locking/lockdep.c:-1 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3772 [inline] validate_chain kernel/locking/lockdep.c:3793 [inline] __lock_acquire+0x1b40/0x6544 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x54/0x6c kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] free_extent_buffer_stale+0x2c/0x240 fs/btrfs/extent_io.c:4803 btrfs_force_cow_block+0xc60/0x187c fs/btrfs/ctree.c:534 btrfs_cow_block+0x2d0/0x710 fs/btrfs/ctree.c:623 btrfs_search_slot+0xa54/0x2364 fs/btrfs/ctree.c:2087 btrfs_search_prev_slot fs/btrfs/free-space-tree.c:135 [inline] add_free_space_extent fs/btrfs/free-space-tree.c:904 [inline] __add_to_free_space_tree+0x38c/0xad8 fs/btrfs/free-space-tree.c:1015 add_to_free_space_tree+0x114/0x2b8 fs/btrfs/free-space-tree.c:1044 do_free_extent_accounting fs/btrfs/extent-tree.c:2867 [inline] __btrfs_free_extent+0xd70/0x2320 fs/btrfs/extent-tree.c:3205 run_delayed_tree_ref fs/btrfs/extent-tree.c:1696 [inline] run_one_delayed_ref fs/btrfs/extent-tree.c:1720 [inline] btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:1969 [inline] __btrfs_run_delayed_refs+0xba4/0x3280 fs/btrfs/extent-tree.c:2032 btrfs_run_delayed_refs+0x124/0x47c fs/btrfs/extent-tree.c:2163 btrfs_commit_transaction+0x1d4/0x29f0 fs/btrfs/transaction.c:2174 btrfs_commit_super+0xac/0xc8 fs/btrfs/disk-io.c:4541 close_ctree+0x3ec/0xa80 fs/btrfs/disk-io.c:4748 btrfs_put_super+0x70/0x80 fs/btrfs/super.c:397 generic_shutdown_super+0x130/0x324 fs/super.c:501 kill_anon_super+0x4c/0x80 fs/super.c:1128 btrfs_kill_super+0x40/0x58 fs/btrfs/super.c:2448 deactivate_locked_super+0xac/0x124 fs/super.c:332 deactivate_super+0xe8/0x108 fs/super.c:363 cleanup_mnt+0x37c/0x404 fs/namespace.c:1182 __cleanup_mnt+0x20/0x30 fs/namespace.c:1189 task_work_run+0x1ec/0x270 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x1f70/0x2b0c arch/arm64/kernel/signal.c:1137 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585