======================================================
WARNING: possible circular locking dependency detected
6.16.0-syzkaller-11322-g352af6a011d5 #0 Tainted: G        W          
------------------------------------------------------
syz.4.1014/8909 is trying to acquire lock:
ffff88805e12a250 (&wnd->rw_lock){++++}-{4:4}, at: ntfs_look_for_free_space+0xd3/0x600 fs/ntfs3/fsntfs.c:362

but task is already holding lock:
ffff8880577456d0 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:859

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->file.run_lock#2){++++}-{4:4}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       down_read+0x97/0x1f0 kernel/locking/rwsem.c:1522
       run_unpack_ex+0x7e5/0xba0 fs/ntfs3/run.c:1119
       ntfs_read_mft fs/ntfs3/inode.c:401 [inline]
       ntfs_iget5+0x232b/0x37c0 fs/ntfs3/inode.c:540
       dir_search_u+0x1df/0x2c0 fs/ntfs3/dir.c:264
       ntfs_lookup+0xfb/0x1f0 fs/ntfs3/namei.c:85
       lookup_one_qstr_excl+0x131/0x360 fs/namei.c:1697
       filename_create+0x224/0x3c0 fs/namei.c:4140
       do_mknodat+0x184/0x4d0 fs/namei.c:4272
       __do_sys_mknodat fs/namei.c:4313 [inline]
       __se_sys_mknodat fs/namei.c:4310 [inline]
       __x64_sys_mknodat+0xa7/0xc0 fs/namei.c:4310
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&wnd->rw_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
       down_write_nested+0x3e/0x60 kernel/locking/rwsem.c:1691
       ntfs_look_for_free_space+0xd3/0x600 fs/ntfs3/fsntfs.c:362
       attr_allocate_clusters+0x1c1/0x6d0 fs/ntfs3/attrib.c:159
       attr_set_size+0x14a4/0x2c70 fs/ntfs3/attrib.c:574
       ntfs_set_size+0x164/0x200 fs/ntfs3/inode.c:861
       ntfs_extend+0x1d9/0x970 fs/ntfs3/file.c:359
       ntfs_setattr+0x2e8/0xbe0 fs/ntfs3/file.c:780
       notify_change+0xb34/0xe60 fs/attr.c:552
       do_truncate+0x1a4/0x220 fs/open.c:68
       vfs_truncate+0x493/0x520 fs/open.c:118
       do_sys_truncate+0xdb/0x190 fs/open.c:141
       __do_sys_truncate fs/open.c:153 [inline]
       __se_sys_truncate fs/open.c:151 [inline]
       __x64_sys_truncate+0x5b/0x70 fs/open.c:151
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 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(&ni->file.run_lock#2);
                               lock(&wnd->rw_lock);
                               lock(&ni->file.run_lock#2);
  lock(&wnd->rw_lock);

 *** DEADLOCK ***

4 locks held by syz.4.1014/8909:
 #0: ffff88805c96e488 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff8880577458e8 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:874 [inline]
 #1: ffff8880577458e8 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
 #2: ffff888057745630 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1113 [inline]
 #2: ffff888057745630 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_set_size+0x131/0x200 fs/ntfs3/inode.c:858
 #3: ffff8880577456d0 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:859

stack backtrace:
CPU: 1 UID: 0 PID: 8909 Comm: syz.4.1014 Tainted: G        W           6.16.0-syzkaller-11322-g352af6a011d5 #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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
 down_write_nested+0x3e/0x60 kernel/locking/rwsem.c:1691
 ntfs_look_for_free_space+0xd3/0x600 fs/ntfs3/fsntfs.c:362
 attr_allocate_clusters+0x1c1/0x6d0 fs/ntfs3/attrib.c:159
 attr_set_size+0x14a4/0x2c70 fs/ntfs3/attrib.c:574
 ntfs_set_size+0x164/0x200 fs/ntfs3/inode.c:861
 ntfs_extend+0x1d9/0x970 fs/ntfs3/file.c:359
 ntfs_setattr+0x2e8/0xbe0 fs/ntfs3/file.c:780
 notify_change+0xb34/0xe60 fs/attr.c:552
 do_truncate+0x1a4/0x220 fs/open.c:68
 vfs_truncate+0x493/0x520 fs/open.c:118
 do_sys_truncate+0xdb/0x190 fs/open.c:141
 __do_sys_truncate fs/open.c:153 [inline]
 __se_sys_truncate fs/open.c:151 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:151
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe0e37feb69
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:00007fe0e165e038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007fe0e3a25fa0 RCX: 00007fe0e37feb69
RDX: 0000000000000000 RSI: 000000000008fff5 RDI: 0000200000000180
RBP: 00007fe0e3881df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe0e3a25fa0 R15: 00007fff3559aaa8
 </TASK>