======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.35/5889 is trying to acquire lock:
ffff88804391ecf8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x391/0x1610 fs/hfsplus/extents.c:264

but task is already holding lock:
ffff88803a7998e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa9/0xd30 fs/hfsplus/bitmap.c:35

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sbi->alloc_mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:580
       hfsplus_block_allocate+0xa9/0xd30 fs/hfsplus/bitmap.c:35
       hfsplus_file_extend+0xb77/0x1df0 fs/hfsplus/extents.c:468
       hfsplus_bmap_reserve+0x170/0x590 fs/hfsplus/btree.c:512
       hfsplus_create_cat+0x1ec/0x1240 fs/hfsplus/catalog.c:272
       hfsplus_mknod+0x184/0x3c0 fs/hfsplus/dir.c:532
       lookup_open+0xc17/0x1a60 fs/namei.c:4567
       open_last_lookups fs/namei.c:4767 [inline]
       path_openat+0x67c/0x1d60 fs/namei.c:4997
       do_file_open+0x23e/0x4a0 fs/namei.c:5029
       do_sys_openat2+0x115/0x200 fs/open.c:1417
       do_sys_open fs/open.c:1423 [inline]
       __do_sys_openat fs/open.c:1439 [inline]
       __se_sys_openat fs/open.c:1434 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1434
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3209 [inline]
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
       lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
       __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:580
       hfsplus_get_block+0x391/0x1610 fs/hfsplus/extents.c:264
       block_read_full_folio+0x29f/0x810 fs/buffer.c:2308
       filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2520
       do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4156
       do_read_cache_page mm/filemap.c:4222 [inline]
       read_cache_page+0x5d/0x170 mm/filemap.c:4231
       read_mapping_page include/linux/pagemap.h:1009 [inline]
       hfsplus_block_allocate+0xf7/0xd30 fs/hfsplus/bitmap.c:37
       hfsplus_file_extend+0xb77/0x1df0 fs/hfsplus/extents.c:468
       hfsplus_get_block+0x41f/0x1610 fs/hfsplus/extents.c:249
       __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030
       block_write_begin fs/buffer.c:2144 [inline]
       cont_write_begin+0x71b/0xac0 fs/buffer.c:2506
       hfsplus_write_begin+0x126/0x1e0 fs/hfsplus/inode.c:56
       generic_perform_write+0x2ad/0x8b0 mm/filemap.c:4374
       generic_file_write_iter+0xaf/0x330 mm/filemap.c:4517
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x61e/0xbb0 fs/read_write.c:687
       ksys_write+0x156/0x270 fs/read_write.c:739
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->alloc_mutex);
                               lock(&HFSPLUS_I(inode)->extents_lock);
                               lock(&sbi->alloc_mutex);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

locks held by syz.0.35/5889: 4, last CPU#1:
 #0: ffff88803b5d6510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #0: ffff88803b5d6510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
 #1: ffff88803baa6808 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff88803baa6808 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
 #2: ffff88803baa6638 (&hip->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21c/0x1df0 fs/hfsplus/extents.c:457
 #3: ffff88803a7998e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa9/0xd30 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 1 UID: 0 PID: 5889 Comm: syz.0.35 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087
 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219
 check_prev_add kernel/locking/lockdep.c:3209 [inline]
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
 mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:580
 hfsplus_get_block+0x391/0x1610 fs/hfsplus/extents.c:264
 block_read_full_folio+0x29f/0x810 fs/buffer.c:2308
 filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2520
 do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4156
 do_read_cache_page mm/filemap.c:4222 [inline]
 read_cache_page+0x5d/0x170 mm/filemap.c:4231
 read_mapping_page include/linux/pagemap.h:1009 [inline]
 hfsplus_block_allocate+0xf7/0xd30 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0xb77/0x1df0 fs/hfsplus/extents.c:468
 hfsplus_get_block+0x41f/0x1610 fs/hfsplus/extents.c:249
 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030
 block_write_begin fs/buffer.c:2144 [inline]
 cont_write_begin+0x71b/0xac0 fs/buffer.c:2506
 hfsplus_write_begin+0x126/0x1e0 fs/hfsplus/inode.c:56
 generic_perform_write+0x2ad/0x8b0 mm/filemap.c:4374
 generic_file_write_iter+0xaf/0x330 mm/filemap.c:4517
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61e/0xbb0 fs/read_write.c:687
 ksys_write+0x156/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f78c85ce159
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:00007fff9d3c51f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f78c8855fa0 RCX: 00007f78c85ce159
RDX: 0000000000010448 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f78c866503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78c8855fac R14: 00007f78c8855fa0 R15: 00007f78c8855fa0
 </TASK>