======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.8.846/13935 is trying to acquire lock:
ffff88805fce2678 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453

but task is already holding lock:
ffff8880342cc0a0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock#2/1){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
       hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28
       hfsplus_file_truncate+0x39b/0xc30 fs/hfsplus/extents.c:579
       hfsplus_setattr+0x1c4/0x270 fs/hfsplus/inode.c:286
       notify_change+0xc18/0xf60 fs/attr.c:556
       do_truncate+0x1c2/0x250 fs/open.c:68
       handle_truncate fs/namei.c:4279 [inline]
       do_open fs/namei.c:4675 [inline]
       path_openat+0x2fc4/0x38a0 fs/namei.c:4830
       do_file_open+0x23e/0x4a0 fs/namei.c:4859
       do_sys_openat2+0x113/0x200 fs/open.c:1366
       do_sys_open fs/open.c:1372 [inline]
       __do_sys_open fs/open.c:1380 [inline]
       __se_sys_open fs/open.c:1376 [inline]
       __x64_sys_open+0x11e/0x150 fs/open.c:1376
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&HFSPLUS_I(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 kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
       __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
       hfsplus_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453
       hfsplus_bmap_reserve+0x128/0x520 fs/hfsplus/btree.c:358
       __hfsplus_ext_write_extent+0x2b0/0x5e0 fs/hfsplus/extents.c:104
       __hfsplus_ext_cache_extent+0x9b/0x780 fs/hfsplus/extents.c:186
       hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
       hfsplus_file_extend+0x4af/0x1d70 fs/hfsplus/extents.c:457
       hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:245
       __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142
       block_write_begin fs/buffer.c:2253 [inline]
       cont_write_begin+0x737/0xae0 fs/buffer.c:2591
       hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
       cont_expand_zero fs/buffer.c:2519 [inline]
       cont_write_begin+0x2e7/0xae0 fs/buffer.c:2581
       hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
       generic_cont_expand_simple+0x146/0x210 fs/buffer.c:2482
       hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:280
       notify_change+0xc18/0xf60 fs/attr.c:556
       do_truncate+0x1c2/0x250 fs/open.c:68
       vfs_truncate+0x4b7/0x540 fs/open.c:118
       do_sys_truncate+0xf3/0x1c0 fs/open.c:142
       __do_sys_truncate fs/open.c:154 [inline]
       __se_sys_truncate fs/open.c:152 [inline]
       __x64_sys_truncate+0x5b/0x70 fs/open.c:152
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 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#2/1);
                               lock(&HFSPLUS_I(inode)->extents_lock);
                               lock(&tree->tree_lock#2/1);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

4 locks held by syz.8.846/13935:
 #0: ffff888035942480 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
 #1: ffff888062d23f58 (&sb->s_type->i_mutex_key#40){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:1033 [inline]
 #1: ffff888062d23f58 (&sb->s_type->i_mutex_key#40){++++}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63
 #2: ffff888062d23cf8 (&hip->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453
 #3: ffff8880342cc0a0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28

stack backtrace:
CPU: 1 UID: 0 PID: 13935 Comm: syz.8.846 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 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 kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
 __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
 mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
 hfsplus_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453
 hfsplus_bmap_reserve+0x128/0x520 fs/hfsplus/btree.c:358
 __hfsplus_ext_write_extent+0x2b0/0x5e0 fs/hfsplus/extents.c:104
 __hfsplus_ext_cache_extent+0x9b/0x780 fs/hfsplus/extents.c:186
 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
 hfsplus_file_extend+0x4af/0x1d70 fs/hfsplus/extents.c:457
 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142
 block_write_begin fs/buffer.c:2253 [inline]
 cont_write_begin+0x737/0xae0 fs/buffer.c:2591
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 cont_expand_zero fs/buffer.c:2519 [inline]
 cont_write_begin+0x2e7/0xae0 fs/buffer.c:2581
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 generic_cont_expand_simple+0x146/0x210 fs/buffer.c:2482
 hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:280
 notify_change+0xc18/0xf60 fs/attr.c:556
 do_truncate+0x1c2/0x250 fs/open.c:68
 vfs_truncate+0x4b7/0x540 fs/open.c:118
 do_sys_truncate+0xf3/0x1c0 fs/open.c:142
 __do_sys_truncate fs/open.c:154 [inline]
 __se_sys_truncate fs/open.c:152 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:152
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc7a434c629
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:00007fc7a25a6028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007fc7a45c5fa0 RCX: 00007fc7a434c629
RDX: 0000000000000000 RSI: 0000000000041bfc RDI: 0000200000000040
RBP: 00007fc7a43e2b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc7a45c6038 R14: 00007fc7a45c5fa0 R15: 00007ffd4c5266d8
 </TASK>
------------[ cut here ]------------
rtmutex deadlock detected
WARNING: kernel/locking/rtmutex.c:1674 at rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674, CPU#1: syz.8.846/13935
Modules linked in:
CPU: 1 UID: 0 PID: 13935 Comm: syz.8.846 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674
Code: 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 81 00 00 00 48 89 f7 e8 56 3a 01 00 48 8d 3d bf 4a 49 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1d 33 c3 29 07 4c 8d
RSP: 0018:ffffc900059d6d10 EFLAGS: 00010286
RAX: 0000000080000000 RBX: ffffc900059d6da0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8ba643e0 RDI: ffffffff8f6d5780
RBP: ffffc900059d6ea8 R08: ffffffff8f6a25b7 R09: 1ffffffff1ed44b6
R10: dffffc0000000000 R11: fffffbfff1ed44b7 R12: 1ffff92000b3adb0
R13: ffffffff8b2406dd R14: ffff8880342cc048 R15: dffffc0000000000
FS:  00007fc7a25a66c0(0000) GS:ffff888126443000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f356c651000 CR3: 000000005e186000 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+0x760/0x7b0 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
 mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552
 hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28
 hfsplus_ext_read_extent fs/hfsplus/extents.c:216 [inline]
 hfsplus_file_extend+0x46d/0x1d70 fs/hfsplus/extents.c:457
 hfsplus_bmap_reserve+0x128/0x520 fs/hfsplus/btree.c:358
 __hfsplus_ext_write_extent+0x2b0/0x5e0 fs/hfsplus/extents.c:104
 __hfsplus_ext_cache_extent+0x9b/0x780 fs/hfsplus/extents.c:186
 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
 hfsplus_file_extend+0x4af/0x1d70 fs/hfsplus/extents.c:457
 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142
 block_write_begin fs/buffer.c:2253 [inline]
 cont_write_begin+0x737/0xae0 fs/buffer.c:2591
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 cont_expand_zero fs/buffer.c:2519 [inline]
 cont_write_begin+0x2e7/0xae0 fs/buffer.c:2581
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 generic_cont_expand_simple+0x146/0x210 fs/buffer.c:2482
 hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:280
 notify_change+0xc18/0xf60 fs/attr.c:556
 do_truncate+0x1c2/0x250 fs/open.c:68
 vfs_truncate+0x4b7/0x540 fs/open.c:118
 do_sys_truncate+0xf3/0x1c0 fs/open.c:142
 __do_sys_truncate fs/open.c:154 [inline]
 __se_sys_truncate fs/open.c:152 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:152
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc7a434c629
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:00007fc7a25a6028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007fc7a45c5fa0 RCX: 00007fc7a434c629
RDX: 0000000000000000 RSI: 0000000000041bfc RDI: 0000200000000040
RBP: 00007fc7a43e2b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc7a45c6038 R14: 00007fc7a45c5fa0 R15: 00007ffd4c5266d8
 </TASK>
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	41 57                	push   %r15
   b:	41 56                	push   %r14
   d:	41 55                	push   %r13
   f:	41 54                	push   %r12
  11:	53                   	push   %rbx
  12:	83 ff dd             	cmp    $0xffffffdd,%edi
  15:	0f 85 81 00 00 00    	jne    0x9c
  1b:	48 89 f7             	mov    %rsi,%rdi
  1e:	e8 56 3a 01 00       	call   0x13a79
  23:	48 8d 3d bf 4a 49 04 	lea    0x4494abf(%rip),%rdi        # 0x4494ae9
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	4c 8d 3d 00 00 00 00 	lea    0x0(%rip),%r15        # 0x36
  36:	65 48 8b 1d 33 c3 29 	mov    %gs:0x729c333(%rip),%rbx        # 0x729c371
  3d:	07
  3e:	4c                   	rex.WR
  3f:	8d                   	.byte 0x8d