loop9: detected capacity change from 0 to 64
hfs: unable to locate alternate MDB
hfs: continuing without an alternate MDB
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.9.1430/16976 is trying to acquire lock:
ffff888049e350e8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x14c0 fs/hfs/extent.c:397

but task is already holding lock:
ffff888064f6a0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x2c0 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}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547
       hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_extend_file+0x2f6/0x14c0 fs/hfs/extent.c:401
       hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
       hfs_cat_create+0x1c5/0x730 fs/hfs/catalog.c:104
       hfs_mkdir+0x6c/0xe0 fs/hfs/dir.c:232
       vfs_mkdir+0x306/0x510 fs/namei.c:4453
       do_mkdirat+0x247/0x590 fs/namei.c:4486
       __do_sys_mkdirat fs/namei.c:4503 [inline]
       __se_sys_mkdirat fs/namei.c:4501 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xfa0 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/rtmutex_api.c:535 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547
       hfs_extend_file+0xda/0x14c0 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+0x31e/0x14c0 fs/hfs/extent.c:401
       hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
       __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
       block_write_begin fs/buffer.c:2256 [inline]
       cont_write_begin+0x789/0xb50 fs/buffer.c:2594
       hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
       cont_expand_zero fs/buffer.c:2522 [inline]
       cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
       hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
       hfs_file_truncate+0x19d/0xad0 fs/hfs/extent.c:495
       hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:665
       notify_change+0xc18/0xf60 fs/attr.c:546
       do_truncate+0x1a4/0x220 fs/open.c:68
       do_ftruncate+0x495/0x550 fs/open.c:195
       do_sys_ftruncate fs/open.c:210 [inline]
       __do_sys_ftruncate fs/open.c:215 [inline]
       __se_sys_ftruncate fs/open.c:213 [inline]
       __x64_sys_ftruncate+0x92/0xf0 fs/open.c:213
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

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.9.1430/16976:
 #0: ffff88804e0ae480 (sb_writers#24){.+.+}-{0:0}, at: do_ftruncate+0x436/0x550 fs/open.c:194
 #1: ffff88805e594b80 (&sb->s_type->i_mutex_key#32){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:985 [inline]
 #1: ffff88805e594b80 (&sb->s_type->i_mutex_key#32){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
 #2: ffff88805e5949a8 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x14c0 fs/hfs/extent.c:397
 #3: ffff888064f6a0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 1 UID: 0 PID: 16976 Comm: syz.9.1430 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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/rtmutex_api.c:535 [inline]
 mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547
 hfs_extend_file+0xda/0x14c0 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+0x31e/0x14c0 fs/hfs/extent.c:401
 hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
 block_write_begin fs/buffer.c:2256 [inline]
 cont_write_begin+0x789/0xb50 fs/buffer.c:2594
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2522 [inline]
 cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 hfs_file_truncate+0x19d/0xad0 fs/hfs/extent.c:495
 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:665
 notify_change+0xc18/0xf60 fs/attr.c:546
 do_truncate+0x1a4/0x220 fs/open.c:68
 do_ftruncate+0x495/0x550 fs/open.c:195
 do_sys_ftruncate fs/open.c:210 [inline]
 __do_sys_ftruncate fs/open.c:215 [inline]
 __se_sys_ftruncate fs/open.c:213 [inline]
 __x64_sys_ftruncate+0x92/0xf0 fs/open.c:213
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fee02e1efc9
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:00007fee01086038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007fee03075fa0 RCX: 00007fee02e1efc9
RDX: 0000000000000000 RSI: 0000000008800000 RDI: 0000000000000006
RBP: 00007fee02ea1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fee03076038 R14: 00007fee03075fa0 R15: 00007ffc92a97e58
 </TASK>
------------[ cut here ]------------
rtmutex deadlock detected
WARNING: CPU: 1 PID: 16976 at kernel/locking/rtmutex.c:1674 rt_mutex_handle_deadlock+0x28/0xb0 kernel/locking/rtmutex.c:1674
Modules linked in:
CPU: 1 UID: 0 PID: 16976 Comm: syz.9.1430 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:rt_mutex_handle_deadlock+0x28/0xb0 kernel/locking/rtmutex.c:1674
Code: 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 8c 00 00 00 48 89 f7 e8 a6 3c 01 00 90 48 c7 c7 e0 18 eb 8a e8 39 8f c0 f6 90 <0f> 0b 90 90 4c 8d 3d 00 00 00 00 65 48 8b 1c 25 08 40 a2 91 4c 8d
RSP: 0018:ffffc9000565ed30 EFLAGS: 00010246
RAX: 80a5f4c9a61d6d00 RBX: ffffc9000565edc0 RCX: 0000000000080000
RDX: ffffc9000d8ab000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000565eec8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed101712487b R12: 1ffff92000acbdb4
R13: ffffffff8ac270a9 R14: ffff888064f6a048 R15: dffffc0000000000
FS:  00007fee010866c0(0000) GS:ffff888126efc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31913ff8 CR3: 000000004e1c6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1734 [inline]
 __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
 rt_mutex_slowlock+0x692/0x6e0 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline]
 mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547
 hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x2f6/0x14c0 fs/hfs/extent.c:401
 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+0x31e/0x14c0 fs/hfs/extent.c:401
 hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
 block_write_begin fs/buffer.c:2256 [inline]
 cont_write_begin+0x789/0xb50 fs/buffer.c:2594
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2522 [inline]
 cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 hfs_file_truncate+0x19d/0xad0 fs/hfs/extent.c:495
 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:665
 notify_change+0xc18/0xf60 fs/attr.c:546
 do_truncate+0x1a4/0x220 fs/open.c:68
 do_ftruncate+0x495/0x550 fs/open.c:195
 do_sys_ftruncate fs/open.c:210 [inline]
 __do_sys_ftruncate fs/open.c:215 [inline]
 __se_sys_ftruncate fs/open.c:213 [inline]
 __x64_sys_ftruncate+0x92/0xf0 fs/open.c:213
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fee02e1efc9
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:00007fee01086038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007fee03075fa0 RCX: 00007fee02e1efc9
RDX: 0000000000000000 RSI: 0000000008800000 RDI: 0000000000000006
RBP: 00007fee02ea1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fee03076038 R14: 00007fee03075fa0 R15: 00007ffc92a97e58
 </TASK>