BUG: MAX_LOCKDEP_CHAINS too low!
turning off the locking correctness validator.
CPU: 0 PID: 6237 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x6c/0xb0 kernel/locking/spinlock.c:162
 __stack_depot_save+0x1c8/0x4ac lib/stackdepot.c:479
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_set_track+0x64/0x80 mm/kasan/common.c:53
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505
 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x74/0x430 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 slab_alloc mm/slub.c:3367 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
 kmem_cache_alloc+0x22c/0x308 mm/slub.c:3383
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 __alloc_extent_buffer+0x40/0x1d4 fs/btrfs/extent_io.c:4280
 alloc_extent_buffer+0x154/0x1098 fs/btrfs/extent_io.c:4603
 btrfs_find_create_tree_block+0x3c/0x50 fs/btrfs/disk-io.c:893
 btrfs_init_new_buffer fs/btrfs/extent-tree.c:4920 [inline]
 btrfs_alloc_tree_block+0x1e8/0x1164 fs/btrfs/extent-tree.c:5039
 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
 lookup_inline_extent_backref+0x28c/0xe74 fs/btrfs/extent-tree.c:847
 lookup_extent_backref fs/btrfs/extent-tree.c:1074 [inline]
 __btrfs_free_extent+0x228/0x22ac fs/btrfs/extent-tree.c:2984
 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+0xbb4/0x32f4 fs/btrfs/extent-tree.c:2032
 btrfs_run_delayed_refs+0x124/0x46c fs/btrfs/extent-tree.c:2163
 commit_cowonly_roots+0x550/0x71c fs/btrfs/transaction.c:1328
 btrfs_commit_transaction+0x10e8/0x2884 fs/btrfs/transaction.c:2444
 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 c9fe44da-de57-406a-8241-57ec7d4412cf