======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.1061/17493 is trying to acquire lock:
ffff888038826258 (&wnd->rw_lock){++++}-{4:4}, at: ntfs_look_for_free_space+0xd9/0x650 fs/ntfs3/fsntfs.c:362

but task is already holding lock:
ffff88807d4dbf10 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:861

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->file.run_lock#2){++++}-{4:4}:
       down_read+0x97/0x200 kernel/locking/rwsem.c:1537
       run_unpack_ex+0x7fa/0xb90 fs/ntfs3/run.c:1135
       ntfs_read_mft fs/ntfs3/inode.c:401 [inline]
       ntfs_iget5+0x2416/0x38f0 fs/ntfs3/inode.c:542
       dir_search_u+0x1fd/0x2e0 fs/ntfs3/dir.c:265
       ntfs_lookup+0x100/0x1d0 fs/ntfs3/namei.c:85
       __lookup_slow+0x2d2/0x440 fs/namei.c:1916
       lookup_slow+0x53/0x70 fs/namei.c:1933
       walk_component fs/namei.c:2279 [inline]
       lookup_last fs/namei.c:2780 [inline]
       path_lookupat+0x3f5/0x8c0 fs/namei.c:2804
       filename_lookup+0x256/0x5d0 fs/namei.c:2833
       __do_sys_mount_setattr fs/namespace.c:5123 [inline]
       __se_sys_mount_setattr+0x1a0/0x280 fs/namespace.c:5091
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 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 kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
       down_write_nested+0x3e/0x60 kernel/locking/rwsem.c:1706
       ntfs_look_for_free_space+0xd9/0x650 fs/ntfs3/fsntfs.c:362
       attr_allocate_clusters+0x1bd/0x6b0 fs/ntfs3/attrib.c:159
       attr_set_size+0x14cf/0x2cf0 fs/ntfs3/attrib.c:574
       ntfs_set_size+0x164/0x200 fs/ntfs3/inode.c:863
       ntfs_fallocate+0xab0/0x1140 fs/ntfs3/file.c:746
       vfs_fallocate+0x672/0x7f0 fs/open.c:340
       ksys_fallocate fs/open.c:364 [inline]
       __do_sys_fallocate fs/open.c:369 [inline]
       __se_sys_fallocate fs/open.c:367 [inline]
       __x64_sys_fallocate+0xc0/0x110 fs/open.c:367
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x14d/0xf80 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.4.1061/17493:
 #0: ffff888055dcc480 (sb_writers#25){++++}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
 #0: ffff888055dcc480 (sb_writers#25){++++}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:339
 #1: ffff88807d4dc128 (&sb->s_type->i_mutex_key#35){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #1: ffff88807d4dc128 (&sb->s_type->i_mutex_key#35){+.+.}-{4:4}, at: ntfs_fallocate+0x2f1/0x1140 fs/ntfs3/file.c:606
 #2: ffff88807d4dbe70 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
 #2: ffff88807d4dbe70 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_set_size+0x131/0x200 fs/ntfs3/inode.c:860
 #3: ffff88807d4dbf10 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:861

stack backtrace:
CPU: 0 UID: 0 PID: 17493 Comm: syz.4.1061 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 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 kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
 down_write_nested+0x3e/0x60 kernel/locking/rwsem.c:1706
 ntfs_look_for_free_space+0xd9/0x650 fs/ntfs3/fsntfs.c:362
 attr_allocate_clusters+0x1bd/0x6b0 fs/ntfs3/attrib.c:159
 attr_set_size+0x14cf/0x2cf0 fs/ntfs3/attrib.c:574
 ntfs_set_size+0x164/0x200 fs/ntfs3/inode.c:863
 ntfs_fallocate+0xab0/0x1140 fs/ntfs3/file.c:746
 vfs_fallocate+0x672/0x7f0 fs/open.c:340
 ksys_fallocate fs/open.c:364 [inline]
 __do_sys_fallocate fs/open.c:369 [inline]
 __se_sys_fallocate fs/open.c:367 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c3a75bf79
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:00007f4c389b6028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f4c3a9d5fa0 RCX: 00007f4c3a75bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f4c3a7f27e0 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000008ffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c3a9d6038 R14: 00007f4c3a9d5fa0 R15: 00007ffff8780278
 </TASK>