BUG: MAX_LOCKDEP_CHAINS too low! turning off the locking correctness validator. CPU: 0 PID: 16982 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026 Call trace: dump_backtrace+0x1c0/0x1ec 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+0xf4/0x15c 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+0x1864/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c 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] btrfs_add_reserved_bytes+0x60/0x6ac fs/btrfs/block-group.c:3546 find_free_extent+0x326c/0x4844 fs/btrfs/extent-tree.c:4503 btrfs_reserve_extent+0x244/0x520 fs/btrfs/extent-tree.c:4621 btrfs_alloc_tree_block+0x19c/0x1164 fs/btrfs/extent-tree.c:5034 btrfs_force_cow_block+0x3ac/0x188c fs/btrfs/ctree.c:450 btrfs_cow_block+0x2d0/0x708 fs/btrfs/ctree.c:623 btrfs_search_slot+0xa50/0x237c fs/btrfs/ctree.c:-1 btrfs_update_root+0xd4/0xa4c fs/btrfs/root-tree.c:132 commit_fs_roots+0x440/0x678 fs/btrfs/transaction.c:1465 btrfs_commit_transaction+0x1028/0x2884 fs/btrfs/transaction.c:2421 btrfs_sync_fs+0x530/0xa28 fs/btrfs/super.c:1535 sync_filesystem+0x1a0/0x218 fs/sync.c:66 generic_shutdown_super+0x70/0x324 fs/super.c:474 kill_anon_super+0x4c/0x80 fs/super.c:1128 btrfs_kill_super+0x40/0x58 fs/btrfs/super.c:2448 deactivate_locked_super+0xac/0x120 fs/super.c:332 deactivate_super+0xe4/0x104 fs/super.c:363 cleanup_mnt+0x390/0x418 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1ec/0x278 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x1fa0/0x2aa4 arch/arm64/kernel/signal.c:1151 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+0x98/0x128 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 BTRFS info (device loop8): last unmount of filesystem 24c7a497-3402-47dd-bef8-82358f5f30e0