============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.3.374/7687 is trying to acquire lock:
ffff88807ee000f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xdb/0x1220 fs/hfs/extent.c:397

but task is already holding lock:
ffff88807ee00778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xdb/0x1220 fs/hfs/extent.c:397

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

       CPU0
       ----
  lock(&HFS_I(tree->inode)->extents_lock);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

5 locks held by syz.3.374/7687:
 #0: ffff888024b30418 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff88807ee00fb8 (&type->i_mutex_dir_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff88807ee00fb8 (&type->i_mutex_dir_key#11){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
 #1: ffff88807ee00fb8 (&type->i_mutex_dir_key#11){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
 #2: ffff8880643340b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfs_find_init+0x17e/0x1f0 fs/hfs/bfind.c:-1
 #3: ffff88807ee00778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xdb/0x1220 fs/hfs/extent.c:397
 #4: ffff8880643360b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x17e/0x1f0 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 0 PID: 7687 Comm: syz.3.374 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3856 [inline]
 __lock_acquire+0x5d40/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747
 hfs_extend_file+0xdb/0x1220 fs/hfs/extent.c:397
 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x317/0x1220 fs/hfs/extent.c:401
 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
 hfs_cat_create+0x1b4/0x620 fs/hfs/catalog.c:104
 hfs_create+0x66/0xd0 fs/hfs/dir.c:202
 lookup_open fs/namei.c:3496 [inline]
 open_last_lookups fs/namei.c:3564 [inline]
 path_openat+0x1277/0x3190 fs/namei.c:3794
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb6cb58f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb6cc372038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb6cb7e6090 RCX: 00007fb6cb58f749
RDX: 0000000000143041 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fb6cb613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb6cb7e6128 R14: 00007fb6cb7e6090 R15: 00007ffdc4f418c8
 </TASK>
hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7687 at fs/hfs/bnode.c:520 hfs_bnode_create+0x3b9/0x440 fs/hfs/bnode.c:519
Modules linked in:
CPU: 0 PID: 7687 Comm: syz.3.374 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:hfs_bnode_create+0x3b9/0x440 fs/hfs/bnode.c:520
Code: c3 c0 8a 89 ee e8 57 13 06 08 e9 73 fd ff ff e8 ad 78 2f ff 4c 89 ef e8 e5 01 1b 08 48 c7 c7 80 c3 c0 8a 89 ee e8 37 13 06 08 <0f> 0b eb b7 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 7f fc ff ff 4c
RSP: 0018:ffffc9000ef0f098 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff888064336000 RCX: 7868a2824d8c3b00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc9000ef0eca7 R09: 1ffff92001de1d94
R10: dffffc0000000000 R11: fffff52001de1d95 R12: 0000000000000000
R13: ffff8880643360e0 R14: ffff88802e716d00 R15: dffffc0000000000
FS:  00007fb6cc3726c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb6cc351d58 CR3: 000000005c534000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 hfs_bmap_alloc+0x53b/0x5c0 fs/hfs/btree.c:326
 hfs_btree_inc_height+0xf7/0xac0 fs/hfs/brec.c:490
 hfs_brec_insert+0x742/0xbd0 fs/hfs/brec.c:148
 __hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124
 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x317/0x1220 fs/hfs/extent.c:401
 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
 hfs_cat_create+0x1b4/0x620 fs/hfs/catalog.c:104
 hfs_create+0x66/0xd0 fs/hfs/dir.c:202
 lookup_open fs/namei.c:3496 [inline]
 open_last_lookups fs/namei.c:3564 [inline]
 path_openat+0x1277/0x3190 fs/namei.c:3794
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb6cb58f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb6cc372038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb6cb7e6090 RCX: 00007fb6cb58f749
RDX: 0000000000143041 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fb6cb613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb6cb7e6128 R14: 00007fb6cb7e6090 R15: 00007ffdc4f418c8
 </TASK>