BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! turning off the locking correctness validator. CPU: 0 PID: 13180 Comm: syz.3.1439 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 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 __mutex_lock_common+0x190/0x1f38 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 remove_from_free_space_tree+0x17c/0x9ec fs/btrfs/free-space-tree.c:850 alloc_reserved_extent+0x58/0x3d0 fs/btrfs/extent-tree.c:4692 alloc_reserved_tree_block fs/btrfs/extent-tree.c:4843 [inline] run_delayed_tree_ref fs/btrfs/extent-tree.c:1691 [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+0x145c/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 create_snapshot+0x4ec/0x838 fs/btrfs/ioctl.c:856 btrfs_mksubvol+0x554/0x6bc fs/btrfs/ioctl.c:1008 btrfs_mksnapshot+0xc4/0x154 fs/btrfs/ioctl.c:1054 __btrfs_ioctl_snap_create+0x310/0x3f8 fs/btrfs/ioctl.c:2218 btrfs_ioctl_snap_create_v2+0x1a4/0x38c fs/btrfs/ioctl.c:2305 btrfs_ioctl+0xa88/0xbd0 fs/btrfs/ioctl.c:-1 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585