ntfs3: loop0: Failed to initialize $Extend/$Reparse.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1545/12220 is trying to acquire lock:
ffff8880246e0270 (&wnd->rw_lock){++++}-{3:3}, at: ntfs_look_for_free_space+0xd4/0x600 fs/ntfs3/fsntfs.c:362

but task is already holding lock:
ffff88805e209070 (&ni->file.run_lock#2){++++}-{3:3}, at: ntfs_extend_mft+0x13e/0x450 fs/ntfs3/fsntfs.c:511

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->file.run_lock#2){++++}-{3:3}:
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       run_unpack_ex+0x7e6/0xba0 fs/ntfs3/run.c:1117
       ntfs_read_mft fs/ntfs3/inode.c:401 [inline]
       ntfs_iget5+0x22e3/0x3750 fs/ntfs3/inode.c:533
       dir_search_u+0x1e0/0x2b0 fs/ntfs3/dir.c:264
       ntfs_lookup+0xfb/0x1f0 fs/ntfs3/namei.c:85
       __lookup_slow+0x281/0x3b0 fs/namei.c:1694
       lookup_slow+0x53/0x70 fs/namei.c:1711
       walk_component+0x2be/0x3f0 fs/namei.c:2002
       lookup_last fs/namei.c:2459 [inline]
       path_lookupat+0x169/0x440 fs/namei.c:2483
       filename_lookup+0x1f4/0x510 fs/namei.c:2512
       user_path_at_empty+0x42/0x60 fs/namei.c:2909
       user_path_at include/linux/namei.h:57 [inline]
       do_sys_truncate+0xa7/0x1a0 fs/open.c:133
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&wnd->rw_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
       lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
       down_write_nested+0x9e/0x1f0 kernel/locking/rwsem.c:1689
       ntfs_look_for_free_space+0xd4/0x600 fs/ntfs3/fsntfs.c:362
       attr_allocate_clusters+0x1c2/0x6d0 fs/ntfs3/attrib.c:159
       attr_set_size+0x14a0/0x2c60 fs/ntfs3/attrib.c:575
       ntfs_extend_mft+0x163/0x450 fs/ntfs3/fsntfs.c:512
       ntfs_look_free_mft+0x5f6/0xd40 fs/ntfs3/fsntfs.c:709
       ntfs_create_inode+0x524/0x3680 fs/ntfs3/inode.c:1343
       ntfs_mkdir+0x42/0x60 fs/ntfs3/namei.c:222
       vfs_mkdir+0x296/0x440 fs/namei.c:4113
       do_mkdirat+0x1d4/0x440 fs/namei.c:4136
       __do_sys_mkdirat fs/namei.c:4151 [inline]
       __se_sys_mkdirat fs/namei.c:4149 [inline]
       __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ni->file.run_lock#2);
                               lock(&wnd->rw_lock);
                               lock(&ni->file.run_lock#2);
  lock(&wnd->rw_lock);

 *** DEADLOCK ***

5 locks held by syz.0.1545/12220:
 #0: ffff888079938418 (sb_writers#33){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403
 #1: ffff88805e20c610 (&type->i_mutex_dir_key#22/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #1: ffff88805e20c610 (&type->i_mutex_dir_key#22/1){+.+.}-{3:3}, at: filename_create+0x1f6/0x460 fs/namei.c:3882
 #2: ffff88805e20c360
 (&ni->ni_lock#2/6){+.+.}-{3:3}, at: ni_lock_dir fs/ntfs3/ntfs_fs.h:1124 [inline]
 (&ni->ni_lock#2/6){+.+.}-{3:3}, at: ntfs_create_inode+0x171/0x3680 fs/ntfs3/inode.c:1257
 #3: ffff8880246e0128 (&wnd->rw_lock/1){+.+.}-{3:3}, at: ntfs_look_free_mft+0x164/0xd40 fs/ntfs3/fsntfs.c:571
 #4: ffff88805e209070 (&ni->file.run_lock#2){++++}-{3:3}, at: ntfs_extend_mft+0x13e/0x450 fs/ntfs3/fsntfs.c:511

stack backtrace:
CPU: 0 PID: 12220 Comm: syz.0.1545 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 down_write_nested+0x9e/0x1f0 kernel/locking/rwsem.c:1689
 ntfs_look_for_free_space+0xd4/0x600 fs/ntfs3/fsntfs.c:362
 attr_allocate_clusters+0x1c2/0x6d0 fs/ntfs3/attrib.c:159
 attr_set_size+0x14a0/0x2c60 fs/ntfs3/attrib.c:575
 ntfs_extend_mft+0x163/0x450 fs/ntfs3/fsntfs.c:512
 ntfs_look_free_mft+0x5f6/0xd40 fs/ntfs3/fsntfs.c:709
 ntfs_create_inode+0x524/0x3680 fs/ntfs3/inode.c:1343
 ntfs_mkdir+0x42/0x60 fs/ntfs3/namei.c:222
 vfs_mkdir+0x296/0x440 fs/namei.c:4113
 do_mkdirat+0x1d4/0x440 fs/namei.c:4136
 __do_sys_mkdirat fs/namei.c:4151 [inline]
 __se_sys_mkdirat fs/namei.c:4149 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6347b8d617
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 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:00007f6348b16e68 EFLAGS: 00000246
 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f6348b16ef0 RCX: 00007f6347b8d617
RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000c0
R13: 00007f6348b16eb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>