loop7: detected capacity change from 0 to 64
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.7.1772/15471 is trying to acquire lock:
ffff888058a841f8 (&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:
ffff8880339a40b0 (&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/mutex.c:598 [inline]
       __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
       hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_get_block+0x51b/0xbd0 fs/hfs/extent.c:366
       block_read_full_folio+0x29f/0x830 fs/buffer.c:2420
       filemap_read_folio+0x117/0x380 mm/filemap.c:2450
       do_read_cache_folio+0x358/0x590 mm/filemap.c:4037
       do_read_cache_page mm/filemap.c:4103 [inline]
       read_cache_page+0x5d/0x170 mm/filemap.c:4112
       read_mapping_page include/linux/pagemap.h:1001 [inline]
       __hfs_bnode_create+0x521/0xb20 fs/hfs/bnode.c:388
       hfs_bnode_find+0x24c/0xf50 fs/hfs/bnode.c:433
       hfs_brec_find+0x172/0x510 fs/hfs/bfind.c:135
       hfs_brec_read+0x24/0x110 fs/hfs/bfind.c:174
       hfs_cat_find_brec+0x15c/0x3f0 fs/hfs/catalog.c:194
       hfs_fill_super+0x4ae/0x6a0 fs/hfs/super.c:354
       get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
       vfs_get_tree+0x92/0x2b0 fs/super.c:1751
       fc_mount fs/namespace.c:1208 [inline]
       do_new_mount_fc fs/namespace.c:3651 [inline]
       do_new_mount+0x302/0xa10 fs/namespace.c:3727
       do_mount fs/namespace.c:4050 [inline]
       __do_sys_mount fs/namespace.c:4238 [inline]
       __se_sys_mount+0x313/0x410 fs/namespace.c:4215
       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/mutex.c:598 [inline]
       __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
       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+0x78c/0xb50 fs/buffer.c:2594
       hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
       generic_perform_write+0x2c5/0x900 mm/filemap.c:4255
       generic_file_write_iter+0x117/0x550 mm/filemap.c:4398
       new_sync_write fs/read_write.c:593 [inline]
       vfs_write+0x5c9/0xb30 fs/read_write.c:686
       ksys_write+0x145/0x250 fs/read_write.c:738
       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 ***

5 locks held by syz.7.1772/15471:
 #0: ffff888078c637b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1232
 #1: ffff888066e6e420 (sb_writers#31){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline]
 #1: ffff888066e6e420 (sb_writers#31){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #2: ffff888057f01ca0 (&sb->s_type->i_mutex_key#40){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
 #2: ffff888057f01ca0 (&sb->s_type->i_mutex_key#40){+.+.}-{4:4}, at: generic_file_write_iter+0xeb/0x550 mm/filemap.c:4395
 #3: ffff888057f01af8 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x14c0 fs/hfs/extent.c:397
 #4: ffff8880339a40b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 1 UID: 0 PID: 15471 Comm: syz.7.1772 Not tainted syzkaller #0 PREEMPT(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/mutex.c:598 [inline]
 __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
 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+0x78c/0xb50 fs/buffer.c:2594
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4255
 generic_file_write_iter+0x117/0x550 mm/filemap.c:4398
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 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: 0033:0x7f966e98efc9
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:00007f966cbf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f966ebe6090 RCX: 00007f966e98efc9
RDX: 00000000000101bf RSI: 0000200000000380 RDI: 0000000000000005
RBP: 00007f966ea11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f966ebe6128 R14: 00007f966ebe6090 R15: 00007ffd90c8a498
 </TASK>
hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: fs/hfs/bnode.c:520 at hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520, CPU#0: syz.7.1772/15471
Modules linked in:
CPU: 0 UID: 0 PID: 15471 Comm: syz.7.1772 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520
Code: 82 8b 89 ee e8 20 3d 88 fe e9 cf fc ff ff e8 16 1c 21 ff 4c 89 ef e8 ae bf b3 08 48 c7 c7 a0 40 82 8b 89 ee e8 00 3d 88 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:ffffc9000470ee20 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff8880339a4000 RCX: bde0149f3f55e600
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa6c0 R12: 0000000000000000
R13: ffff8880339a40e0 R14: ffff888078443e00 R15: dffffc0000000000
FS:  00007f966cbf66c0(0000) GS:ffff888125cef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8ff31a6b0 CR3: 000000006174e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 hfs_bmap_alloc+0x5bb/0x640 fs/hfs/btree.c:326
 hfs_btree_inc_height+0xf6/0xac0 fs/hfs/brec.c:490
 hfs_brec_insert+0x7c2/0xc60 fs/hfs/brec.c:148
 __hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124
 __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+0x78c/0xb50 fs/buffer.c:2594
 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4255
 generic_file_write_iter+0x117/0x550 mm/filemap.c:4398
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 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: 0033:0x7f966e98efc9
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:00007f966cbf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f966ebe6090 RCX: 00007f966e98efc9
RDX: 00000000000101bf RSI: 0000200000000380 RDI: 0000000000000005
RBP: 00007f966ea11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f966ebe6128 R14: 00007f966ebe6090 R15: 00007ffd90c8a498
 </TASK>