======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u8:15/8683 is trying to acquire lock:
ffff88802274d578 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1230 fs/hfs/extent.c:397

but task is already holding lock:
ffff88804f19e0b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x184/0x200 fs/hfs/bfind.c:-1

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock#2/1){+.+.}-{4:4}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       __mutex_lock_common kernel/locking/mutex.c:598 [inline]
       __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
       hfs_find_init+0x184/0x200 fs/hfs/bfind.c:-1
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_extend_file+0x2ee/0x1230 fs/hfs/extent.c:401
       hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
       hfs_cat_create+0x1b3/0x640 fs/hfs/catalog.c:104
       hfs_create+0x66/0xe0 fs/hfs/dir.c:202
       lookup_open fs/namei.c:3708 [inline]
       open_last_lookups fs/namei.c:3807 [inline]
       path_openat+0x14f4/0x3830 fs/namei.c:4043
       do_filp_open+0x1fa/0x410 fs/namei.c:4073
       do_sys_openat2+0x121/0x1c0 fs/open.c:1435
       do_sys_open fs/open.c:1450 [inline]
       __do_sys_open fs/open.c:1458 [inline]
       __se_sys_open fs/open.c:1454 [inline]
       __x64_sys_open+0x11e/0x150 fs/open.c:1454
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
       __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       __mutex_lock_common kernel/locking/mutex.c:598 [inline]
       __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
       hfs_extend_file+0xda/0x1230 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_write_extent+0x161/0x1e0 fs/hfs/extent.c:144
       hfs_write_inode+0x91/0x7d0 fs/hfs/inode.c:429
       write_inode fs/fs-writeback.c:1525 [inline]
       __writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1745
       writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976
       wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156
       wb_do_writeback fs/fs-writeback.c:2303 [inline]
       wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343
       process_one_work kernel/workqueue.c:3236 [inline]
       process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
       worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
       kthread+0x711/0x8a0 kernel/kthread.c:463
       ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&tree->tree_lock#2/1);
                               lock(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock#2/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

3 locks held by kworker/u8:15/8683:
 #0: ffff88801e6bc948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88801e6bc948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
 #1: ffffc9000ed97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc9000ed97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
 #2: ffff88804f19e0b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x184/0x200 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 0 UID: 0 PID: 8683 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 __mutex_lock_common kernel/locking/mutex.c:598 [inline]
 __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
 hfs_extend_file+0xda/0x1230 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_write_extent+0x161/0x1e0 fs/hfs/extent.c:144
 hfs_write_inode+0x91/0x7d0 fs/hfs/inode.c:429
 write_inode fs/fs-writeback.c:1525 [inline]
 __writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1745
 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976
 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8683 at fs/hfs/bnode.c:520 hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520
Modules linked in:
CPU: 0 UID: 0 PID: 8683 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
Workqueue: writeback wb_workfn (flush-7:2)
RIP: 0010:hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520
Code: a1 8b 89 ee e8 40 d8 8d fe e9 cf fc ff ff e8 a6 e6 25 ff 4c 89 ef e8 9e 95 e2 08 48 c7 c7 a0 ce a1 8b 89 ee e8 20 d8 8d fe 90 <0f> 0b 90 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c d6 fb ff ff
RSP: 0018:ffffc9000ed96c20 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff88804f19e000 RCX: ff34eaeb69bbff00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1f4 R12: 0000000000000000
R13: ffff88804f19e0e0 R14: ffff88801c35a300 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f58af7716c0 CR3: 0000000029d47000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 hfs_bmap_alloc+0x5bb/0x640 fs/hfs/btree.c:326
 hfs_btree_inc_height+0xf6/0xac0 fs/hfs/brec.c:471
 hfs_brec_insert+0x743/0xbd0 fs/hfs/brec.c:148
 __hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124
 hfs_ext_write_extent+0x161/0x1e0 fs/hfs/extent.c:144
 hfs_write_inode+0x91/0x7d0 fs/hfs/inode.c:429
 write_inode fs/fs-writeback.c:1525 [inline]
 __writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1745
 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976
 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>