======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.7.273/7855 is trying to acquire lock:
ffff8880382d70e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa9/0xd30 fs/hfsplus/bitmap.c:35

but task is already holding lock:
ffff88802560a2b8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21c/0x1df0 fs/hfsplus/extents.c:457

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}:
       __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

-> #0 (&sbi->alloc_mutex){+.+.}-{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_block_allocate+0xa9/0xd30 fs/hfsplus/bitmap.c:35
       hfsplus_file_extend+0xb77/0x1df0 fs/hfsplus/extents.c:468
       hfsplus_create_attributes_file fs/hfsplus/xattr.c:277 [inline]
       __hfsplus_setxattr+0xd1d/0x2800 fs/hfsplus/xattr.c:431
       hfsplus_initxattrs+0x1ae/0x280 fs/hfsplus/xattr_security.c:59
       security_inode_init_security+0x29b/0x3e0 security/security.c:1370
       hfsplus_mknod+0x1de/0x3c0 fs/hfsplus/dir.c:536
       hfsplus_mkdir+0x26/0x40 fs/hfsplus/dir.c:573
       vfs_mkdir+0x408/0x620 fs/namei.c:5410
       filename_mkdirat+0x289/0x520 fs/namei.c:5443
       __do_sys_mkdirat fs/namei.c:5464 [inline]
       __se_sys_mkdirat+0x35/0x150 fs/namei.c:5461
       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(&HFSPLUS_I(inode)->extents_lock);
                               lock(&sbi->alloc_mutex);
                               lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&sbi->alloc_mutex);

 *** DEADLOCK ***

locks held by syz.7.273/7855: 5, last CPU#1:
 #0: ffff88803e708510 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff88802560ab48 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
 #1: ffff88802560ab48 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline]
 #1: ffff88802560ab48 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline]
 #1: ffff88802560ab48 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5092
 #2: ffff8880382d7178 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_mknod+0x86/0x3c0 fs/hfsplus/dir.c:521
 #3: ffff8880335ba0a0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x179/0x2e0 fs/hfsplus/bfind.c:29
 #4: ffff88802560a2b8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21c/0x1df0 fs/hfsplus/extents.c:457

stack backtrace:
CPU: 1 UID: 0 PID: 7855 Comm: syz.7.273 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_block_allocate+0xa9/0xd30 fs/hfsplus/bitmap.c:35
 hfsplus_file_extend+0xb77/0x1df0 fs/hfsplus/extents.c:468
 hfsplus_create_attributes_file fs/hfsplus/xattr.c:277 [inline]
 __hfsplus_setxattr+0xd1d/0x2800 fs/hfsplus/xattr.c:431
 hfsplus_initxattrs+0x1ae/0x280 fs/hfsplus/xattr_security.c:59
 security_inode_init_security+0x29b/0x3e0 security/security.c:1370
 hfsplus_mknod+0x1de/0x3c0 fs/hfsplus/dir.c:536
 hfsplus_mkdir+0x26/0x40 fs/hfsplus/dir.c:573
 vfs_mkdir+0x408/0x620 fs/namei.c:5410
 filename_mkdirat+0x289/0x520 fs/namei.c:5443
 __do_sys_mkdirat fs/namei.c:5464 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5461
 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: 0033:0x7f91fe8ccfc7
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007f91fcb25e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f91fcb25ee0 RCX: 00007f91fe8ccfc7
RDX: 00000000000001ff RSI: 0000200000000240 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000200000000080 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000240
R13: 00007f91fcb25ea0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>