======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.1694/12587 is trying to acquire lock:
ffff88807a9041f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xff/0x1380 fs/hfs/extent.c:397

but task is already holding lock:
ffff88807a28c0b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x17e/0x1f0 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){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
       hfs_find_init+0x17e/0x1f0 fs/hfs/bfind.c:-1
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_extend_file+0x361/0x1380 fs/hfs/extent.c:401
       hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
       hfs_cat_create+0x1fe/0x6b0 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+0x12a0/0x3230 fs/namei.c:3794
       do_filp_open+0x1f5/0x430 fs/namei.c:3824
       do_sys_openat2+0x134/0x1d0 fs/open.c:1421
       do_sys_open fs/open.c:1436 [inline]
       __do_sys_open fs/open.c:1444 [inline]
       __se_sys_open fs/open.c:1440 [inline]
       __x64_sys_open+0x11f/0x140 fs/open.c:1440
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
       hfs_extend_file+0xff/0x1380 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+0x3a0/0x1380 fs/hfs/extent.c:401
       hfs_get_block+0x413/0xc50 fs/hfs/extent.c:353
       __block_write_begin_int+0x57f/0x1af0 fs/buffer.c:2124
       __block_write_begin fs/buffer.c:2173 [inline]
       block_write_begin+0x9a/0x1e0 fs/buffer.c:2234
       cont_write_begin+0x5ee/0x810 fs/buffer.c:2591
       hfs_write_begin+0x8b/0xd0 fs/hfs/inode.c:58
       cont_expand_zero fs/buffer.c:2518 [inline]
       cont_write_begin+0x2b1/0x810 fs/buffer.c:2581
       hfs_write_begin+0x8b/0xd0 fs/hfs/inode.c:58
       hfs_file_truncate+0x1c4/0xa10 fs/hfs/extent.c:494
       hfs_inode_setattr+0x4af/0x6e0 fs/hfs/inode.c:659
       notify_change+0xb0d/0xe10 fs/attr.c:499
       do_truncate+0x1b0/0x240 fs/open.c:66
       vfs_truncate+0x266/0x300 fs/open.c:112
       do_sys_truncate+0xf6/0x1c0 fs/open.c:135
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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 ***

4 locks held by syz.1.1694/12587:
 #0: ffff88805c914418 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff88807a905738 (&sb->s_type->i_mutex_key#33){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff88807a905738 (&sb->s_type->i_mutex_key#33){+.+.}-{3:3}, at: do_truncate+0x19c/0x240 fs/open.c:64
 #2: ffff88807a905578 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xff/0x1380 fs/hfs/extent.c:397
 #3: ffff88807a28c0b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x17e/0x1f0 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 0 PID: 12587 Comm: syz.1.1694 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
 hfs_extend_file+0xff/0x1380 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+0x3a0/0x1380 fs/hfs/extent.c:401
 hfs_get_block+0x413/0xc50 fs/hfs/extent.c:353
 __block_write_begin_int+0x57f/0x1af0 fs/buffer.c:2124
 __block_write_begin fs/buffer.c:2173 [inline]
 block_write_begin+0x9a/0x1e0 fs/buffer.c:2234
 cont_write_begin+0x5ee/0x810 fs/buffer.c:2591
 hfs_write_begin+0x8b/0xd0 fs/hfs/inode.c:58
 cont_expand_zero fs/buffer.c:2518 [inline]
 cont_write_begin+0x2b1/0x810 fs/buffer.c:2581
 hfs_write_begin+0x8b/0xd0 fs/hfs/inode.c:58
 hfs_file_truncate+0x1c4/0xa10 fs/hfs/extent.c:494
 hfs_inode_setattr+0x4af/0x6e0 fs/hfs/inode.c:659
 notify_change+0xb0d/0xe10 fs/attr.c:499
 do_truncate+0x1b0/0x240 fs/open.c:66
 vfs_truncate+0x266/0x300 fs/open.c:112
 do_sys_truncate+0xf6/0x1c0 fs/open.c:135
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fee1bd9c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fee1cd31028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007fee1c015fa0 RCX: 00007fee1bd9c799
RDX: 0000000000000000 RSI: 0000000003000000 RDI: 0000200000000900
RBP: 00007fee1be32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fee1c016038 R14: 00007fee1c015fa0 R15: 00007ffcb65302c8
 </TASK>