======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc5-syzkaller-00038-g733923397fd9 #0 Not tainted
------------------------------------------------------
syz.2.77/7073 is trying to acquire lock:
ffff888031911af8 (&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:
ffff8880295200b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x165/0x1e0 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/1){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:602 [inline]
       __mutex_lock+0x181/0xe50 kernel/locking/mutex.c:747
       hfs_find_init+0x165/0x1e0 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:234
       hfs_cat_move+0x18c/0x960 fs/hfs/catalog.c:310
       hfs_rename+0x1dc/0x2d0 fs/hfs/dir.c:299
       vfs_rename+0xb99/0xec0 fs/namei.c:5137
       do_renameat2+0x878/0xc50 fs/namei.c:5286
       __do_sys_rename fs/namei.c:5333 [inline]
       __se_sys_rename fs/namei.c:5331 [inline]
       __x64_sys_rename+0x82/0x90 fs/namei.c:5331
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3168 [inline]
       check_prevs_add kernel/locking/lockdep.c:3287 [inline]
       validate_chain kernel/locking/lockdep.c:3911 [inline]
       __lock_acquire+0x15bc/0x2df0 kernel/locking/lockdep.c:5240
       lock_acquire+0x120/0x350 kernel/locking/lockdep.c:5871
       __mutex_lock_common kernel/locking/mutex.c:602 [inline]
       __mutex_lock+0x181/0xe50 kernel/locking/mutex.c:747
       hfs_extend_file+0xda/0x1230 fs/hfs/extent.c:397
       hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:234
       __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+0x316/0x1230 fs/hfs/extent.c:401
       hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
       __block_write_begin_int+0x6b5/0x18f0 fs/buffer.c:2151
       block_write_begin fs/buffer.c:2262 [inline]
       cont_write_begin+0x789/0xb40 fs/buffer.c:2601
       hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
       cont_expand_zero fs/buffer.c:2528 [inline]
       cont_write_begin+0x2fa/0xb40 fs/buffer.c:2591
       hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
       hfs_file_truncate+0x190/0x9c0 fs/hfs/extent.c:494
       hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:654
       notify_change+0xb36/0xe40 fs/attr.c:552
       do_truncate+0x1a4/0x220 fs/open.c:68
       vfs_truncate+0x493/0x520 fs/open.c:118
       do_sys_truncate+0xdb/0x190 fs/open.c:141
       __do_sys_truncate fs/open.c:153 [inline]
       __se_sys_truncate fs/open.c:151 [inline]
       __x64_sys_truncate+0x5b/0x70 fs/open.c:151
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

4 locks held by syz.2.77/7073:
 #0: ffff888034220428 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff88805e47d0a0 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:874 [inline]
 #1: ffff88805e47d0a0 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
 #2: ffff88805e47cef8 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1230 fs/hfs/extent.c:397
 #3: ffff8880295200b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x165/0x1e0 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 0 UID: 0 PID: 7073 Comm: syz.2.77 Not tainted 6.16.0-rc5-syzkaller-00038-g733923397fd9 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ed/0x300 kernel/locking/lockdep.c:2046
 check_noncircular+0x130/0x150 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3168 [inline]
 check_prevs_add kernel/locking/lockdep.c:3287 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x15bc/0x2df0 kernel/locking/lockdep.c:5240
 lock_acquire+0x120/0x350 kernel/locking/lockdep.c:5871
 __mutex_lock_common kernel/locking/mutex.c:602 [inline]
 __mutex_lock+0x181/0xe50 kernel/locking/mutex.c:747
 hfs_extend_file+0xda/0x1230 fs/hfs/extent.c:397
 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:234
 __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+0x316/0x1230 fs/hfs/extent.c:401
 hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
 __block_write_begin_int+0x6b5/0x18f0 fs/buffer.c:2151
 block_write_begin fs/buffer.c:2262 [inline]
 cont_write_begin+0x789/0xb40 fs/buffer.c:2601
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2528 [inline]
 cont_write_begin+0x2fa/0xb40 fs/buffer.c:2591
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 hfs_file_truncate+0x190/0x9c0 fs/hfs/extent.c:494
 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:654
 notify_change+0xb36/0xe40 fs/attr.c:552
 do_truncate+0x1a4/0x220 fs/open.c:68
 vfs_truncate+0x493/0x520 fs/open.c:118
 do_sys_truncate+0xdb/0x190 fs/open.c:141
 __do_sys_truncate fs/open.c:153 [inline]
 __se_sys_truncate fs/open.c:151 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:151
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f6c50d8e929
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:00007f6c51b71038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f6c50fb5fa0 RCX: 00007f6c50d8e929
RDX: 0000000000000000 RSI: 0000000008800000 RDI: 0000200000000040
RBP: 00007f6c50e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6c50fb5fa0 R15: 00007ffff0b79828
 </TASK>