============================================
WARNING: possible recursive locking detected
6.16.0-rc5-syzkaller-gec4801305969 #0 Not tainted
--------------------------------------------
syz.2.136/7295 is trying to acquire lock:
ffff0000d8b0a0b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1

but task is already holding lock:
ffff0000d8b0a0b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&tree->tree_lock#2/1);
  lock(&tree->tree_lock#2/1);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

6 locks held by syz.2.136/7295:
 #0: ffff0000d0aa9438 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x1fc/0x2a0 fs/file.c:1217
 #1: ffff0000d8b56428 (sb_writers#23){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline]
 #1: ffff0000d8b56428 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x244/0x97c fs/read_write.c:682
 #2: ffff0000f1c08920 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
 #2: ffff0000f1c08920 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: generic_file_write_iter+0xd4/0x470 mm/filemap.c:4252
 #3: ffff0000f1c08778 (&HFS_I(inode)->extents_lock#2){+.+.}-{4:4}, at: hfs_extend_file+0xd4/0xf4c fs/hfs/extent.c:397
 #4: ffff0000d8b0a0b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1
 #5: ffff0000cc4e0778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xd4/0xf4c fs/hfs/extent.c:397

stack backtrace:
CPU: 0 UID: 0 PID: 7295 Comm: syz.2.136 Not tainted 6.16.0-rc5-syzkaller-gec4801305969 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_deadlock_bug+0x2e8/0x2f0 kernel/locking/lockdep.c:3044
 check_deadlock kernel/locking/lockdep.c:3096 [inline]
 validate_chain kernel/locking/lockdep.c:3898 [inline]
 __lock_acquire+0x2940/0x30a4 kernel/locking/lockdep.c:5240
 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5871
 __mutex_lock_common+0x1d0/0x2190 kernel/locking/mutex.c:602
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799
 hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x238/0xf4c fs/hfs/extent.c:401
 hfs_bmap_reserve+0xd4/0x3e0 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x19c/0x488 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x84/0x750 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x264/0xf4c fs/hfs/extent.c:401
 hfs_get_block+0x2e8/0x9cc fs/hfs/extent.c:353
 __block_write_begin_int+0x53c/0x15e8 fs/buffer.c:2151
 block_write_begin fs/buffer.c:2262 [inline]
 cont_write_begin+0x62c/0x968 fs/buffer.c:2601
 hfs_write_begin+0x7c/0xc4 fs/hfs/inode.c:52
 generic_perform_write+0x23c/0x79c mm/filemap.c:4112
 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4229
 generic_file_write_iter+0x104/0x470 mm/filemap.c:4255
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x62c/0x97c fs/read_write.c:686
 ksys_write+0x120/0x210 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:746
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596